Table of Contents

Table of Contents

Table of Contents

used in this

Proxy Statement the terms “we,” “us,” “our” “Company” or “Trinseo” refer to Trinseo S.A. Proxy materials, including this Proxy Statement are being first provided to shareholders on or about October 20, 2017. Our registered address is 46A avenue John F. Kennedy,L-1855 Luxembourg, Grand Duchy of Luxembourg.

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Table of Contents

QUESTIONS AND ANSWERS ABOUT THE SPECIALGENERAL MEETING AND THE PROXY MATERIALS

Where is the Extraordinary Meeting being held?

We will hold the Extraordinary Meeting at 5:20 p.m., local time on Tuesday, November 28, 2017 at the Sofitel Luxembourg Europe hotel located at 4, rue du Fort Niedergrünewald, BP 512 / Quartier Européen Nord,L-2015 Luxembourg, Grand Duchy of Luxembourg. When you arrive in the lobby, check in at the front desk and ask to be directed to the Trinseo Extraordinary Meeting. We reserve the right to request that you to present a photo ID and verify your status as a shareholder. We will not permit cameras or other recording devices at the Extraordinary Meeting. All cell phones must be turned off once the Extraordinary Meeting is convened.

What will shareholders vote on at the Extraordinary Meeting?

Shareholders will be asked to vote:

Special Meeting at 11:00 a.m., local time, on Wednesday, November 20, 2019 at the Sofitel Luxembourg Europe hotel located at 4, rue du Fort Niedergrünewald, BP 512 / Quartier Européen Nord, L‑2015 Luxembourg, Grand Duchy of Luxembourg. When you arrive in the lobby, check in at the front desk and ask to be directed to the Trinseo Special Meeting. We reserve the right to request that you present a photo ID and verify your status as a shareholder. We will not permit cameras or other recording devices at the Special Meeting. All cell phones must be turned off once the Special Meeting is convened. October 11, 2019 we commenced mailing of a Notice of Internet Availability of Proxy Materials to our shareholders of record and beneficial owners. The Notice explains how to access the proxy materials on the Internet and how to vote your proxy for the Special Meeting. If you received the Notice by mail and would like to receive a printed copy of our proxy materials, please follow the instructions for requesting printed materials included in the Notice.   1. To elect one Class III director, Mr. Henri Steinmetz,two directors specifically named in the proxy statement, each to serve for a term until the 2020Company’s next annual general meetingmeeting; . To approve,  Changes to the Company’s compensation program for non-executive directors. Where is the Special General Meeting being held? We will hold the Special General Meeting at 11:00 a.m., local time, on Wednesday, November 20, 2019 at the Sofitel Luxembourg Europe hotel located at 4, rue du Fort Niedergrünewald, BP 512 / Quartier Européen Nord, L‑2015 Luxembourg, Grand Duchy of shareholders;Luxembourg. When you arrive in the lobby, check in at the front desk and ask to be directed to the Trinseo Special General Meeting. We reserve the right to request that you present a photo ID and verify your status as a shareholder. We will not permit cameras or other recording devices at the Special General Meeting. All cell phones must be turned off once the Special General Meeting is convened.   2. What will shareholders vote on at the Special General Meeting? Shareholders will be asked to vote: 1.   To elect two directors specifically named in the proxy statement, each to serve a term until the Company’s next annual meeting; and 2.   Any other business properly brought before the Extraordinary Meeting of Shareholders.Special General Meeting. We do not expect any other matters to be presented at the meeting. If other matters are properly presented for voting, the persons named as proxies will vote in accordance with their best judgment on those matters. Who is entitled to vote at the Extraordinary Meeting?   Shareholders of record as of the close of business on October 17, 2017 are entitled to vote at the Extraordinary Meeting. On that date, there were 43,703,314 of our ordinary shares outstanding. Each ordinary share is entitled to one vote. What is a shareholder2019 Proxy Statement        3 Table of record?Contents If your shares are registered directly in your name with our transfer agent, American Stock Transfer & Trust Company, LLC, you are considered the shareholder of record for those shares. As the shareholder of record, you have the right to vote your shares. If your shares are held in a stock brokerage account or by a bank, or other holder of record, you are considered the beneficial owner of shares held in street name. Your broker, bank, or other holder of record is the shareholder of record for those shares. As the beneficial owner, you have the right to direct your broker, bank, or other holder of record on how to vote your shares. What constitutes a quorum for consideration of proposals at the Extraordinary Meeting? Under our Articles of Association, the holders of a majority of the ordinary shares outstanding and entitled to vote at the Extraordinary Meeting shall constitute a quorum for the transaction of business at the Extraordinary Meeting. Ordinary shares represented in person or by proxy will be counted for purposes of determining whether a quorum is present. Abstentions and brokernon-votes (if any) will be treated as present at the Extraordinary Meeting and will be counted for quorum purposes. How many votes are required at the Extraordinary Meeting to elect the director nominee? The proposal to elect the director nominee requires the affirmative vote of a majority of the ordinary shares represented in person or by proxy at the Extraordinary Meeting and entitled to vote. 2017 Proxy Statement 1 QUESTIONS AND ANSWERS ABOUT THE EXTRAORDINARYSPECIAL GENERAL MEETING AND THE PROXY MATERIALS   How do I vote? Who is entitled to vote at the Special General Meeting? Shareholders of record as of the close of business on October 18, 2019 are entitled to vote at the Special General Meeting. On that date, there were 39,280,112 of our ordinary shares outstanding. Each ordinary share is entitled to one vote. What is a shareholder of record? If your shares are registered directly in your name with our transfer agent, American Stock Transfer & Trust Company, LLC, you are considered the shareholder of record for those shares. As the shareholder of record, you have the right to vote your shares. If your shares are held in a stock brokerage account or by a bank, or other holder of record, you are considered the beneficial owner of shares held in street name. Your broker, bank, or other holder of record is the shareholder of record for those shares. As the beneficial owner, you have the right to direct your broker, bank, or other holder of record on how to vote your shares.  What constitutes a quorum for consideration of proposals at the Special General Meeting? Under our Articles of Association, the holders of a majority of the ordinary shares outstanding and entitled to vote at the Special General Meeting shall constitute a quorum for the transaction of business at the Special General Meeting. Ordinary shares represented in person or by proxy will be counted for purposes of determining whether a quorum is present. Abstentions and broker non-votes (if any) will be treated as present at the Special General Meeting and will be counted for quorum purposes and will vote in accordance with their best judgment on those matters. How many votes are required to elect directors and to adopt the other proposals at the Special General Meeting? The election of directors and each of the other proposals related to the ordinary resolutions to be voted on require the affirmative vote of a majority of the ordinary shares represented in person or by proxy at the Special General Meeting and entitled to vote.  For advisory votes, the Board takes the voting results under advisement.  How do I vote? If you are a shareholder of record, you may vote in person at the meeting. If you do not wish to vote in person or if you will not be attending the Special General Meeting, you may vote by telephone, or over the Internet, by following the instructions provided in the voting instructions.  You may also complete, sign, and date your proxy card and return it in the prepaid envelope that was included with the proxy materials that you received. If you are a beneficial owner of shares and you wish to vote in person at the Special General Meeting, you must obtain a proxy for the Special General Meeting from your broker, bank, or other shareholder of record and present it to the inspector of election with your ballot. If you do not wish to vote in person or will not be attending the Special General Meeting, you may vote by following the instructions provided in the voting instructions you received from the shareholder of record of your shares. You should have received a proxy card and voting instructions from the shareholder of record of your shares. If you are a shareholder of record, you will receive one proxy card for the Special General Meeting.   If you are a shareholder of record, you may vote in person at the meeting. If you do not wish to vote in person or if you will not be attending the meeting, you may vote by telephone, or over the Internet, by following the instructions provided on your proxy card. You may also complete, sign, and date your proxy card and return it in the prepaid envelope that was included with the printed materials. If you are a beneficial owner of shares and you wish to vote in person at the Extraordinary Meeting, you must obtain a proxy from your broker, bank, or other shareholder of record and present it to the inspector of election with your ballot. If you do not wish to vote in person or will not be attending the Extraordinary Meeting, you may vote by following the proxy voting instructions provided with the proxy materials you received from the shareholder of record of your shares. If you received a printed copy of the proxy materials, you should have received a proxy card and voting instructions from the shareholder of record of your shares. If you submit a signed proxy card for the Extraordinary Meeting but do not fill out the voting instructions, the persons named as proxy holders will vote the shares represented by your proxy “FOR” authorizing the Company, with approval of the Board, to elect one Class III director, Mr. Henri Steinmetz, to serve for a term until the 2020 annual general meeting of shareholders. If there are not sufficient votes to approve the Proposal at the Extraordinary Meeting, in accordance with the Company’s Articles of Association, the chairman may adjourn the Extraordinary Meeting to permit the further solicitation of proxies. Additionally, under Luxembourg law, the Board may adjourn the Extraordinary Meeting for up to four weeks. The persons named as proxies will vote those proxies for such adjournment, unless marked to be voted against the Proposal, to permit the further solicitation of proxies. Abstentions and brokernon-votes, if any, will not have any effect on the result of the vote for adjournment. If any nominee should become unavailable, your shares will be voted for another nominee selected by the Board or for only the remaining nominees. Brokers are not permitted to vote your shares on the Proposal. If your shares are held in the name of a broker or nominee and you do not instruct the broker or nominee how to vote or if you abstain or withhold authority to vote, your shares will not be counted as having been voted, but will be counted as in attendance at the meeting for purposes of a quorum. If you do not vote your shares, you will not have a say on the important proposal to be voted upon at the Extraordinary Meeting. What happens if I abstain from voting or my broker withholds my vote? For the proposal to be considered at the meeting, abstentions are treated as shares that are represented and entitled to vote, so abstaining has the same effect as a negative vote. Shares held by brokers that do not have discretionary authority to vote on the proposal and that have not received voting instructions from their customers are not counted as being represented or entitled to vote on the proposal, which has the effect of reducing the number of affirmative votes needed to approve the proposal. Should I submit a proxy even if I plan to attend the Extraordinary Meeting in person? To ensure that your vote is recorded promptly, please vote as soon as possible, even if you plan to attend the Extraordinary Meeting in person. If you attend the Extraordinary Meeting in person and are a shareholder of record, you may also submit your vote in person, and any previous votes that you submitted will be superseded by the vote that you cast at the Extraordinary Meeting. Internet and phone voting will becut-off at 11:59 p.m., Eastern Time, on November 27, 2017. Who will bear the cost of soliciting votes for the Extraordinary Meeting? We will bear the expense of the solicitation of proxies for the Extraordinary Meeting. Solicitation of proxies may be made by mail, in person or telephone by officers, directors and other employees of the Company and by employees of Broadridge Financial Solutions, Inc. (“Broadridge”). We will reimburse Broadridge and the Company’s banks, brokers, and other custodians, nominees and fiduciaries for their reasonable costs in the preparation and mailing of proxy materials to shareholders. A shareholder may also choose to vote electronically by accessing the Internet site stated on their proxy card or proxy voting instructions or by using the toll-free telephone number provided in in its proxy card or proxy voting instructions. Shareholders that vote through the Internet should understand that there may be costs associated with electronic access, such as usage charges from Internet access providers and telephone companies, which will be borne by the shareholder. Can I revoke my proxy? Your proxy may be revoked by giving notice of revocation to Trinseo in writing, by accessing the Internet site, by using the 2 2017 Proxy Statement 4        2019ProxyStatement Table of Contents QUESTIONS AND ANSWERS ABOUT THE EXTRAORDINARYSPECIALGENERAL MEETING AND THE PROXY MATERIALS toll-free telephone number, or in person at the Extraordinary Meeting. A shareholder may also change his or her vote by executing and returning to the Company a later-dated proxy, by submitting a later-dated electronic vote through the Internet site, by using the toll-free telephone number or in person at the applicable Extraordinary Meeting. The Internet and telephone procedures for voting and for revoking or changing a vote are designed to authenticate shareholders’ identities, to allow shareholders to give their voting instructions and to confirm that shareholders’ instructions have been properly recorded. If you are a shareholder of record and submit a signed proxy card for the Special General Meeting but do not fill out the voting instructions, the persons named as proxy holders will vote the shares represented by your proxy “FOR” the authorization of the Company, with approval of the Board, to elect two directors specifically named in the proxy statement, each to serve a term until the Company’s next annual meeting. If there are not sufficient votes to approve one or more of the proposals at the Special General Meeting, in accordance with the Company’s Articles of Association, the chairman may adjourn the Special General Meeting to permit the further solicitation of proxies. Additionally, under Luxembourg law, the Board may adjourn the Special General Meeting for up to four weeks. The persons named as proxies will vote those proxies for such adjournment, unless marked to be voted against the proposal, to permit the further solicitation of proxies. Abstentions and broker non-votes, if any, will not have any effect on the result of the vote for adjournment. If any nominee should become unavailable, your shares will be voted for another nominee selected by the Board or for only the remaining nominees. Brokers are not permitted to vote your shares on any matter.  If your shares are held in the name of a broker or nominee and you do not instruct the broker or nominee how to vote with respect to the election of directors or if you abstain or withhold authority to vote on any matter, your shares will not be counted as having been voted on those matters, but will be counted as in attendance at the meeting for purposes of a quorum. If you do not vote your shares, you will not have a say on the important issues to be voted upon at the Special General Meeting. What happens if I abstain from voting on a matter or my broker withholds my vote? For each matter to be considered at the Special General Meeting, abstentions are treated as shares that are represented and entitled to vote, so abstaining has the same effect as a negative vote. Shares held by brokers that do not have discretionary authority to vote on a particular proposal and that have not received voting instructions from their customers are not counted as being represented or entitled to vote on the proposal, which has the effect of reducing the number of affirmative votes needed to approve the proposal.   2019 Proxy Statement        5 Table of Contents QUESTIONS AND ANSWERS ABOUT THE SPECIAL GENERAL MEETING AND THE PROXY MATERIALS Should I submit a proxy even if I plan to attend the Special General Meeting in person? To ensure that your vote is recorded promptly, please vote as soon as possible, even if you plan to attend the Special General Meeting in person. If you attend the Special General Meeting in person and are a shareholder of record, you may also submit your vote in person, and any previous votes that you submitted will be superseded by the vote that you cast at the Special General Meeting. Internet and phone voting will be cut-off at 11:59 p.m., Eastern Time, on November 18, 2019. Can I revoke my proxy? Your proxy may be revoked by giving notice of revocation to Trinseo in writing, by accessing the Internet site, by using the toll-free telephone number, or in person at the Special General Meeting. A shareholder may also change his or her vote by executing and returning to the Company a later-dated proxy, by submitting a later-dated electronic vote through the Internet site, by using the toll-free telephone number or in person at the Special General Meeting. The Internet and telephone procedures for voting and for revoking or changing a vote are designed to authenticate shareholders’ identities, to allow shareholders to give their voting instructions and to confirm that shareholders’ instructions have been properly recorded. Who will bear the cost of soliciting votes for the Special General Meeting? We will bear the expense of the solicitation of proxies for the Special General Meeting. Solicitation of proxies may be made by mail, in person or telephone by officers, directors and other employees of the Company and by employees of Broadridge Financial Solutions, Inc. (“Broadridge”). We agreed to pay Broadridge a fee of approximately $43,000 for their assistance with the solicitation of proxies. Additionally, we will reimburse Broadridge and the Company’s banks, brokers, and other custodians, nominees and fiduciaries for their reasonable costs in the preparation and mailing of proxy materials to shareholders. A shareholder may also choose to vote electronically by accessing the Internet site stated in the voting instructions or by using the toll-free telephone number stated in the voting instructions. Shareholders that vote through the Internet should understand that there may be costs associated with electronic access, such as usage charges from Internet access providers and telephone companies, which will be borne by the shareholder. 2017 Proxy Statement 3 PROPOSAL 1—ELECTION OF CLASS III DIRECTOR   6        2019ProxyStatement Table of Contents PROPOSAL 1 Proposal 1—1–Election of Class III DirectorDirectors Trinseo has a classified board of directors currently consisting of three directors with terms expiring in 2018 (Class I), three directors with terms expiring in 2019 (Class II), and two directors with terms expiring in 2020 (Class III). At each annual general meeting of shareholders, directors in one class are elected for a full term of three years to succeed those directors whose terms are expiring. The Class III director nominee, Mr. Henri Steinmetz, will stand for election to serve for a term expiring at the 2020 annual general meeting. The persons named in the enclosed proxy will vote to elect Mr. Steinmetz unless the proxy is marked otherwise. Mr. Steinmetz has indicated his willingness to serve, if elected. However, if Mr. Steinmetz should be unable to serve, the ordinary shares represented by proxies may be voted for a substitute nominee designated by the Board. Management has no reason to believe that Mr. Steinmetz will not serve his term as a director. We seek nominees with established strong professional reputations, sophistication, business acumen and experience in the global materials, chemical and related manufacturing industries. We also seek nominees with experience in substantive areas that are important to our business such as chemical industry expertise, international operations; accounting, finance and capital structure; strategic planning and leadership of complex organizations; human resources and development practices; and innovation. In addition, we believe that our nominees should possess the professional and personal qualifications necessary for board service, and we have highlighted particularly noteworthy attributes in each of the biographies of our directors and our nominee below. Mr. Steinmetz is a new director nominee nominated by the Board to fill the seat vacated by Jeannot Krecké and is standing for election at this Extraordinary General Meeting. If elected, he will hold office until our 2020 annual general meeting of shareholders and until his successor is duly elected and qualified. Mr. Steinmetz offers our Board decades of experience in the chemical industry as well as a global perspective and significant chief executive officer experience. Mr. Steinmetz will not be able to serve as a director unless his appointment is approved by a majority of the votes cast by our shareholders. Trinseo has a Board consisting of three directors with terms expiring in 2020 (Class III), three directors with terms expiring in 2021 (Class I) and four directors with terms expiring annually. Last year our shareholders approved an amendment to our Articles of Association to declassify our Board.  With this amendment, as the term of each of the director classes expires, each class of directors will only be elected for an annual term. Therefore, each of the two director nominees will stand for election at the Company’s next annual general meeting. The persons named in the enclosed proxy will vote to elect Mr. Mark Tomkins and Ms. Sandra Beach Lin as directors unless the Proxy is marked otherwise. Each of the nominees has indicated his or her willingness to serve, if elected. However, if a nominee should be unable to serve, the ordinary shares represented by proxies may be voted for a substitute nominee designated by the Board. Management has no reason to believe that any of the above-mentioned persons will not serve his or her term as a director. We seek nominees with established strong professional reputations, sophistication, business acumen and experience in the global materials, chemical and related manufacturing industries. We also seek nominees with experience in substantive areas that are important to our business such as chemical industry expertise, international operations; accounting, finance and capital structure; strategic planning and operational leadership of complex organizations; human resources and development practices; and innovation. In addition, we believe that our nominees should possess the professional and personal qualifications necessary for board service, and we have highlighted particularly noteworthy attributes in each of the biographies of our directors and our nominees below. 2019 Director Nominees The individuals listed below have been nominated by the Board upon the recommendation of the nominating and corporate governance committee and are standing for election at this Special General Meeting. If elected, they will hold office until our 2020 annual general meeting of shareholders and until their successors are duly elected and qualified.   If Mr. Mark Tomkins and Ms. Sandra Beach Lin nominations are not approved, they will not serve as members of the Company’s Board.   YOUR BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT YOU VOTE “FOR” THE ELECTION OF HENRI STEINMETZ AS A CLASS III DIRECTOR. . YOUR BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT YOU VOTE “FOR” THE ELECTION OF EACH OF THE NOMINEES AS DIRECTOR.   4 2017 Proxy Statement 2019 Proxy Statement        7 Table of Contents PROPOSAL 1—ELECTION OF CLASS III DIRECTOR1 2019 Director Nominee with Term Expiring in 2020 (Class III Director) Mr. Mark Tomkins Age: 64 HENRI STEINMETZ Age:61 Professional Experience: Since 2016From 2005 to 2006, Mr. Steinmetz has served as Chief Executive Officer of the Ceramtec Group, a global supplier of advanced ceramics. From 2009 to 2016, Mr. SteinmetzTomkins was Executive Director and Chief Executive Officer of Ruetgers N.V., Europe’s leading manufacturer of chemical raw materials made from coal tar. Prior to joining Ruetgers N.V., Mr. Steinmetz was President of Sulzer Metco, a worldwide technology leader in coating materials, from 2004 to 2008, and an Executive Vice President at Great Lakes Chemical Corporation from 2000 to 2004. Education: Mr. Steinmetz graduated with a M.S. in metallurgy from the Technical University Clausthal, Germany and has an MBA from INSEAD Fontainebleau, France. Other Public Company Directorships: None Director Qualifications: Mr. Steinmetz has significant global chief executive officer experience and decades of chemical industry experience, which make him well-positioned to provide significant contributions to our Board. 2017 Proxy Statement 5 PROPOSAL 1—ELECTION OF CLASS III DIRECTOR Directors with Terms Expiring in 2018 (Class I Directors) JOSEPH ALVARADO Age:65 Director Since:March 2017 Committee Membership: •    Audit •    Environmental, Health, Safety & Public Policy Professional Experience: Mr. Alvarado is Chairman and Chief Executive Officer of Commercial Metals Company (NYSE: CMC), a global manufacturer, recycler and marketer of steel and other metals. He joined CMC in April 2010 as ExecutiveSenior Vice President and Chief OperatingFinancial Officer was named Presidentof Innovene, at the time, a leading petrochemical and Chief Operating Officer in April 2011, and became President and Chief Executive Officer in September 2011. In January 2017, he passed his President title to his Chief Operating Officer. He has been Chairman of CMC’s board of directors since January 2013.polymers company.  Prior to joining CMC, heInnovene, Mr. Tomkins was Senior Vice President, Chief Financial Officer and Chief Operating OfficerTreasurer of Lone Star Technologies, Inc.Vulcan Minerals, a mineral exploration company, from 20042001 to 2007. In June 2007, following the acquisition of Lone Star Technologies, Inc. by United States Steel Corporation, Mr. Alvarado was named President of U.S. Steel Tubular Products, Inc.2005. He joined Great Lakes Chemical Corp., a division of United States Steel Corporation, a position he held until March 2009. Mr. Alvarado began his career at Inland Steel Company in 1976chemical research, production, sales and spent 21 years with thedistribution company in roles of increasing responsibility. He then served in executive roles with Birmingham Steel Corporation and Ispat North America Inc. until joining Lone Star Technologies. Education: Mr. Alvarado has an MBA from Cornell University and a B.A. degree in Economics from University of Notre Dame. Other Public Company Directorships: Commercial Metals Company (NYSE: CMC) since 2011 Spectra Energy Corp (NYSE: SE) from 2011 until February 2017 Director Qualifications: Mr. Alvarado brings years of experience in a cyclical commodities-driven industry and significant perspective on global operations and strategic planning. 6 2017 Proxy Statement PROPOSAL 1—ELECTION OF CLASS III DIRECTOR JEFFREY J. COTE Age:50 Director Since:May 2014 Committee Membership: •    Audit •    Compensation Professional Experience: Mr. Cote has served as Chief Operating Officer of Sensata Technologies Holding N.V. (NYSE: ST) since July 2012 and as Executive Vice President of its Global Sensing Solutions business since November 2015. He joined Sensata as Senior Vice President and Chief Financial Officer in January 2007, and was appointed Executive Vice President in July 2007. From March 2005from 1998 to December 2006, Mr. Cote was Chief Operating Officer of the law firm Ropes & Gray. From January 2000 to March 2005, Mr. Cote was Chief Operating, Financial and Administrative Officer of Digitas. Previously he worked for Ernst & Young LLP from 1989 until 1997. Mr. Cote is a certified public accountant.2001. Education: Mr. Cote receivedTomkins graduated with a B.A. degreeBachelor of Science in Business AdministrationFinance and a Master of AccountingQuantitative Management and has an MBA from Florida AtlanticEastern Illinois University. Other Public Company Directorships: NoneCurrent Directorships- ServiceMaster (NYSE:  SERV) since 2015 WR Grace & Co (NYSE:  GRA) since 2006 Past Directorships- Klockner Pentaplast since 2016 (Advisory) Elevance Renewable Sciences from 2007 to 2014 CVR Energy (NYSE:  CVI) from 2007 to 2012 Director Qualifications:Mr. Tomkins is a certified public accountant. Mr. Tomkins’ financial, accounting and management expertise, along with his experience on other public and private company boards, qualify him to serve on the Company’s Board. Mr. Cote brings significant management, capital markets 8        2019ProxyStatement Table of Contents PROPOSAL 1 2019 Director Nominee with Term Expiring in 2020 Ms. Sandra Beach Lin Age: 61 Professional Experience: From 2010 to 2011, Ms. Beach Lin was President and accountingChief Executive Officer of Calisolar, Inc., a manufacturer of solar silicon and multicrystalline solar cells. Prior to joining Calisolar, she was Corporate Executive Vice President, then Corporate Executive Vice President, at Celanese Corporation, a global technology and specialty materials company, from 2007 to 2010. Ms. Beach Lin joined Avery Dennison Corporation, a global leader in pressure-sensitive adhesives technology as Group Vice President from 2005 to 2007.  Prior to joining Avery Dennison, from 2002 to 2005, she was President, Alcoa Closure Systems International, a division of Alcoa Incorporated, a global aluminum leader.   From 1994 to 2001, Ms. Beach Lin held various executive positions at Honeywell International, a Fortune 100 diversified technology and manufacturing leader. Education: Ms. Beach Lin graduated with a Bachelor of Business Administration in General Management from the University of Toledo, Ohio and has an MBA in Marketing and Policy and Control from the University of Michigan, Michigan. Other Public Company Directorships: Current Directorships – American Electric Power (NYSE:  AEP) since 2012 Interface Biologics since 2012 Polyone (NYSE: POL) since 2013 Past Directorships- WESCO Internationals from 2002 to 2019 Director Qualifications: Ms. Beach Lin’s extensive senior executive experience, including as a Chief Executive Officer, leading global businesses in multiple industries provides her with valuable skills to ourserve on the Company’s Board. Ms. Lin has a deep understanding of the specialty chemicals industry, a strong operational foundation and wide-ranging international experience. 2019 Proxy Statement        9 Table of Contents PROPOSAL 1     PIERRE-MARIE DE LEENERFrank A. Bozich Age: 58 Age:60 Director Since:May 2014 Since June 2019 Committee Membership: •    Audit •    Environmental, Health, Safety & Public Policy Professional Experience: Mr. De Leener served as interim CEO of Braas Monier Building Group SA from January 2016 to November 2016Bozich became the Company’s President and has been Chairman of its Board of Directors since June 2014. Prior to that, he served as Executive Vice President for PPG Industries, Inc. from July 2010 until December 2012. From June 2008 until August 2011, Mr. De Leener also served as President of PPG Europe S.A. Mr. De Leener previously served as Chief Executive Officer in March 2019. From May 2013 until February 2019, Mr. Bozich had been the President and Chief Executive Officer at the SI Group, Inc., a leading global developer and manufacturer of SigmaKalonphenolic resins and chemicals used in the production of antioxidants, engineering plastics, fuels and lubes, rubber and pharmaceutical ingredients. Prior to joining SI Group Inc.,  Mr. Bozich held several executive management positions at BASF Corporation, a multi-national chemicals and manufacturing corporation, including President of BASF’s Catalysts Division from 1998 until January 2008. In addition, Mr. De Leener served as a member2010 to 2013, Group Vice President of Precious and Base Metal Service, and Group Vice President of the Total Fina operating committee from 1998 until 2001.Integration Management Office. Prior to BASF, Mr. Bozich was Group Vice President, Enterprise Technologies and Ventures at Engelhard Corporation, which was acquired by BASF in 2006. He has also held leadership positions at Rohm and Haas; Croda Adhesives, Inc.; and Apex Adhesives, which he founded in 1986. Education: Mr. De Leener receivedBozich holds a B.A.bachelor’s degree in Economics and PhilosophyChemistry and a Master of Chemical Engineeringmaster’s degree in Business Administration from Catholicthe University of Louvain, Belgium.Chicago, as well as a master’s degree in Chemistry from the University of Illinois. Other Public Company Directorships: NoneCurrent Directorships- OGE Energy Corp (NYSE: OGE) since 2016 Director Qualifications: Mr. De Leener brings valuable managementBozich is an accomplished Chief Executive Officer known for his strong personal leadership and track record of driving business growth and corporate transformation. His breadth of experience in leading chemical industry experience to our Board.businesses in diverse and dynamic global markets is well-suited for the Company’s strategic priorities. 10        2019ProxyStatement Table of Contents PROPOSAL 1   2017 Proxy Statement 7 PROPOSAL 1—ELECTION OF CLASS III DIRECTOR Directors with Terms Expiring in 2019 (Class II Directors)   PHILIP  MARTENS Age: 59 Age:57 Director Since:September 2016 Committee Membership: •    Compensation •    Nominating & Corporate Governance Professional Experience: From February 2011 to April 2015, Mr. Martens served as President and Chief Executive Officer of Novelis, Inc., a leader in aluminum rolled products and can recycling with worldwide operations. He joined Novelis as President and Chief Operating Officer in April 2009. Prior to his employment with Novelis, Mr. Martens served as Senior Vice President of light vehicle systems for ArvinMeritor Inc., a distributor for engine and transmission parts and President and Chief Executive Officer designate of Arvin Innovation, a leading global provider of dynamic motion and control automotive systems. From 1987 to 2005, Mr. Martens held various product development and engineering roles at Ford Motor Company, including his most recent role as a group vice presidentGroup Vice President of product creation from 2003 to 2005. Education: Mr. Martens has an MBA from University of Michigan and received his B.S. degree in mechanical engineering from Virginia Polytechnic Institute. Other Public Company Directorships: Graphic Current Directorships- Packaging Holding Company (NYSE: GPK) – since 2013 Past Directorships- Plexus Corporation (NASDAQ: PLXS) – from 2010 until Februaryto 2017 Director Qualifications: Mr. Martens brings to the board of directorsCompany’s Board significant leadership and management experience in global manufacturing operations, along with innovation expertise. 2019 Proxy Statement        11 Table of Contents PROPOSAL 1 8 2017 Proxy Statement PROPOSAL 1—ELECTION OF CLASS III DIRECTOR   CHRISTOPHER D. PAPPAS Age: 63 Age:62 Director Since:October 2010 Committee Membership: •    Environmental, Health, Safety & Public Policy Professional Experience: Mr. Pappas joined Trinseo aswas the Company’s President and Chief Executive Officer in June 2010 and served as interim chief financial officerChief Financial Officer from November 2015 until June 2016. Mr. Pappas transitioned to the role of Special Adviser to Trinseo’s new President and Chief Executive Officer, Mr. Frank A. Bozich, effective March 2019 and through May 2019. Prior to joining Trinseo, Mr. Pappas held a number of executive positions at NOVA Chemicals of increasing responsibility from July 2000 to November 2009, most recently as President and Chief Executive Officer from May 2009 to November 2009, President & Chief Operations Officer from October 2006 to April 2009 and Vice President and President of Styrenics from July 2000 to September 2006. Before joining NOVA Chemicals, Mr. Pappas was Commercial Vice President of DuPont Dow Elastomers where he joined as Vice President of ethylene elastomers in 1995. Mr. Pappas began his chemicals career in 1978 with The Dow Chemical Company (“Dow”) where he held various sales and managerial positions until 1995. Education: Mr. Pappas holds a B.S. degree in Civil Engineering from the Georgia Institute of Technology and an MBA from the Wharton School of Business at The University of Pennsylvania. Other Public Company Directorships: Current Directorships- FirstEnergy Corp. (NYSE: FE) since 2011 Univar, Inc. (NYSE: UNVR) since 2015 Director Qualifications: Mr. Pappas is highly qualified to serve on ourthe Company’s Board due to his public company board experience and his more than 3040 years of managementbusiness experience with major companies in the chemical industry, and by his previous leadership of the Company since its formation. In these roles he has also acquired and demonstrated substantial financial expertise which is valuable to the Company’s Board. 12        2019ProxyStatement Table of Contents PROPOSAL 1 2017 Proxy Statement 9 PROPOSAL 1—ELECTION OF CLASS III DIRECTOR   STEPHEN M. ZIDE Age: 59 Age:57 Chairman Director Since:June 2010 Committee Membership: •    Compensation •    Nominating & Corporate Governance Professional Experience: Mr. Zide is a senior advisor toretired from Bain Capital, in theLP, a private equity business,investment firm, in 2017, having joined the firm in 1997. From 2001 through 2015, Mr. Zide wasserved as a senior advisor of Bain Capital from 2016 through 2017 and as a Managing Director of Bain Capital.from 2001 through 2015. Prior to joining Bain Capital, Mr. Zide was a partner of the law firm of Kirkland & Ellis LLP, where he was a founding member of the New York office and specialized in representing private equity and venture capital firms. Education: Mr. Zide received an MBA from Harvard Business School, a Juris Doctorate from Boston University School of Law, and a B.A. degree from the University of Rochester. Other Public Company Directorships: Current Directorships- Sensata Technologies B.V. (NYSE: ST) since 2010 Past Directorships- HD Supply Holdings, Inc. (NASDAQ: HDS) from 2007 to 2014 Innophos Holdings, Inc. (NASDAQ: IPHS) from 2004 to 2013 Director Qualifications: Mr. Zide brings to the Company’s Board extensive negotiating and financing expertise gained from his training and experience as a legal advisor, and later as a private equity professional and financial advisor. In addition, Mr. Zide has had significant involvement with the Company since its 2010 formation, and has served as a director of numerous public and private companies during his career in private equity and law. 10 2017 Proxy Statement 2019 Proxy Statement        13 Table of Contents PROPOSAL 1—ELECTION OF CLASS III DIRECTOR1 Directors with Terms Expiring in 2020 (Class III Directors)     K’LYNNE  JOHNSON Age: 50 Age:49 Director Since:March 2017 Committee Membership: •    Compensation •    Nominating & Corporate Governance Professional Experience: Ms. Johnson served as President and Chief Executive Officer of Elevance Renewable Sciences Inc., a specialty chemicals company, from 2007 to 2015, and as Chairwoman from 2015 to 2016. Ms. Johnson joined Elevance after over 20 years’ experience working within the oil and petrochemicals industry for Amoco Corporation and BP p.l.c. (joining BP after its merger with Amoco in 1998). During this time she held both operational and functional roles, culminating in her role as Senior Vice President of Global Derivatives within BP’s global Innovene business, which included P&L accountability for multiple global commodity and specialty chemicals businesses. Education: Ms. Johnson graduated from Brigham Young University with a degree in Management and Organizational Behavior (M.O.B.) and a B.S. in Psychology. Other Public Company Directorships: FMC Current Directorships- Corporation (NYSE: FMC) since 2013 Director Qualifications: Ms. Johnson brings to our boardthe Company’s Board valuable experience in operational leadership and chemical industry and technological expertise. 14        2019ProxyStatement Table of Contents PROPOSAL 1     DONALD T. MISHEFF Age: 62 Age:61 Director Since:February 2015 Committee Membership: •    Audit •    Nominating & Corporate Governance Professional Experience: Mr. Misheff served as managing partner from 2003 until his retirement in 2011 of the Northeast Ohio offices of Ernst & Young LLP, a public accounting firm. As the managing partner of the Northeast Ohio offices of Ernst & Young LLP, Mr. Misheff advised many of the region’s largest companies on financial and corporate governance issues. He began his career with Ernst & Young LLP in 1978 as part of the audit staff and later joined the tax practice, specializing in accounting/financial reporting for income taxes, purchase accounting, and mergers and acquisitions. He has more than 30 years of experience performing, reviewing, and overseeing the audits of financial statements of a wide range of public companies. Education: Mr. Misheff graduated from the University of Akron with a B.S. degree in Accounting. Other Public Company Directorships: Current Directorships- TimkenSteel Corporation (NYSE: TMST) since 2014 First Energy Corp. (NYSE: FE) since 2012 Director Qualifications: Mr. Misheff brings extensive financial, accounting and public company corporate governance experience to ourthe Company’s Board. 2019 Proxy Statement        15 Table of Contents PROPOSAL 1 HENRI STEINMETZ Age: 62 Director Since: November 2017 Committee Membership:      Nominating & Corporate Governance      Environmental, Health, Safety & Public Policy Professional Experience: Since 2016, Mr. Steinmetz has served as Chief Executive Officer of the Ceramtec Group, a global supplier of advanced ceramics. From 2009 to 2016, Mr. Steinmetz was Executive Director and Chief Executive Officer of Ruetgers N.V., Europe’s leading manufacturer of chemical raw materials made from coal tar. Prior to joining Ruetgers N.V., Mr. Steinmetz was President of Sulzer Metco, a worldwide technology leader in coating materials, from 2004 to 2008, and an Executive Vice President at Great Lakes Chemical Corporation from 2000 to 2004. Education: Mr. Steinmetz graduated with a M.S. in metallurgy from the Technical University Clausthal, Germany and has an MBA from INSEAD Fontainebleau, France. Other Public Company Directorships: None Director Qualifications: Mr. Steinmetz brings significant global chief executive officer experience and decades of chemical industry experience to the Company’s Board. 16        2019ProxyStatement Table of Contents PROPOSAL 1 Directors with Terms Expiring in 2021 JOSEPH  ALVARADO Age: 66 Director Since: March 2017 Committee Membership: Audit Environmental, Health, Safety & Public Policy Professional Experience: Mr. Alvarado served as Chief Executive Officer of Commercial Metals Company (NYSE: CMC), a global manufacturer, recycler and marketer of steel and other metals, from September 2011 until September 2017, and as Chairman of CMC’s board of directors from January 2013 until January 2018. He joined CMC in April 2010 as Executive Vice President and Chief Operating Officer, was named President and Chief Operating Officer in April 2011, and became President and Chief Executive Officer in September 2011. In January 2017, he passed his President title to his Chief Operating Officer. Prior to joining CMC, he was President and Chief Operating Officer of Lone Star Technologies, Inc. from 2004 to 2007. In June 2007, following the acquisition of Lone Star Technologies, Inc. by United States Steel Corporation, Mr. Alvarado was named President of U.S. Steel Tubular Products, Inc., a division of United States Steel Corporation, a position he held until March 2009. Mr. Alvarado began his career at Inland Steel Company in 1976 and spent 21 years with the company in roles of increasing responsibility. He then served in executive roles with Birmingham Steel Corporation and Ispat North America Inc. until joining Lone Star Technologies. Education: Mr. Alvarado has an MBA from Cornell University and a B.A. degree in Economics from University of Notre Dame. Other Public Company Directorships: Current Directorships- Kennametal Inc. (NYSE: KMT) since 2018 PNC Financial Services Group Inc. (PNC) since 2019 Past Directorships- Commercial Metals Company (NYSE: CMC) from 2013 to 2018 Spectra Energy Corp (NYSE: SE) from 2011 to 2017 Director Qualifications: Mr. Alvarado brings years of experience in a cyclical commodities-driven industry and significant perspective on global manufacturing operations and strategic planning to the Company’s Board. 2019 Proxy Statement        17 Table of Contents PROPOSAL 1 JEFFREY J. COTE Age: 52 Director Since: May 2014 Committee Membership: Audit Compensation Professional Experience: Mr. Cote has been President and Chief Operating Officer of Sensata Technologies Holding plc (NYSE: ST) since January 2019.  Prior to his appointment, Mr. Cote had served as Chief Operating Officer of Sensata Technologies Holding plc (NYSE: ST) since July 2012 and as Executive Vice President of its Global Sensing Solutions business since November 2015. He joined Sensata as Senior Vice President and Chief Financial Officer in January 2007, and was appointed Executive Vice President in July 2007. From March 2005 to December 2006, Mr. Cote was Chief Operating Officer of the law firm Ropes & Gray. From January 2000 to March 2005, Mr. Cote was Chief Operating, Financial and Administrative Officer of Digitas. Previously he worked for Ernst & Young LLP from 1989 until 1997. Mr. Cote is a certified public accountant. Education: Mr. Cote received a B.A. degree in Business Administration and a Master of Accounting from Florida Atlantic University. Other Public Company Directorships: None Director Qualifications: Mr. Cote brings significant management, financial and accounting experience to the Company’s Board. 18        2019ProxyStatement Table of Contents PROPOSAL 1 PIERRE-MARIE  DE  LEENER Age: 60 Director Since: May 2014 Committee Membership: Audit Environmental, Health, Safety & Public Policy Professional Experience: Mr. De Leener served as interim Chief Executive Officer of Braas Monier Building Group SA from January 2016 to November 2016 and as Chairman of its board of directors from June 2014 to March 2017. Prior to that, he served as Executive Vice President for PPG Industries, Inc. from July 2010 until December 2012. From June 2008 until August 2011, Mr. De Leener also served as President of PPG Europe S.A. and as Chief Executive Officer of SigmaKalon Group from 1998 until January 2008. Education: Mr. De Leener received a B.S. degree in Economics and Philosophy and a Master of Chemical Engineering degree from Catholic University of Louvain, Belgium. Other Public Company Directorships: None Director Qualifications: Mr. De Leener brings valuable executive management and chemical industry experience to the Company’s Board.   2017 Proxy Statement 11 CORPORATE GOVERNANCE   2019 Proxy Statement        19 Table of Contents CORPORATE GOVERNANCE Corporate Governance Board Nominees. Under its charter, our nominating and corporate governance committee is responsible for recommending to the Board candidates to stand election to the Board at the Company’s annual general meeting of shareholders and for recommending candidates to fill vacancies on the Board that may occur between annual general meetings. It is the policy of the Board that directors should possess the highest personal and professional ethics, integrity and values. Board members are expected to become and remain informed about the Company, its business and its industry and rigorously prepare for, attend and participate in all Board and applicable committee meetings. The committee evaluates each individual in the context of the Board as a whole, with the objective of recommending a group that can best perpetuate the success of our business and represent shareholdershareholders’ interests through the exercise of sound judgment using its diversity of experience. In addition, the Board considers, in light of our business and Board composition, each director nominee’s experience, qualifications, attributes and skills that are identified in the biographical information contained under “Proposal 1—Election of Class III Director.”1”. The nominating and corporate governance committee considers properly submitted recommendations for candidates to the Board from shareholders. Any shareholder may submit in writing nominations of persons for consideration for each shareholder meeting at which directors are to be elected by not later than the 90th calendar day nor earlier than the 120th calendar day before the date of the annual general meeting. Any shareholder recommendations for consideration by the Board should include the candidate’s name, biographical information, information regarding any relationships between the candidate and the shareholder within the last three years, a statement of recommendation of the candidate from the shareholder, a description of our shares beneficially owned by the shareholder, a description of all arrangements between the candidate and the recommending shareholder and any other person pursuant to which the candidate is being recommended, a written indication of the candidate’s willingness to serve on the Board of Directors, any other information required to be provided under securities laws and regulations, and a written indication to provide such other information as the Board may reasonably request. Recommendations should be sent to Angelo N. Chaclas, Corporate Secretary, Trinseo S.A., 1000 Chesterbrook Boulevard, Suite 300, Berwyn, PA 19312. The Board evaluates candidates for the position of director recommended by shareholders or others in the same manner as candidates from other sources. The Board will determine whether to interview any candidates and may seek additional information about candidates from third-party sources. The Company has engaged an executive search firm to identify potential Board nominees on behalf of the Board. The executive search firm is instructed to identify candidates meeting the Board’s desires with respect to diversity, experience, skill, and qualifications and perform preliminary screenings of such candidates on behalf of the Board. The Board specifically requested the executive search firm identify at least one candidate who was a Luxembourg resident. Mr. Steinmetz is a Luxembourg resident. Board Independence. Our Corporate Governance Guidelines provide that our Board shall consist of such number of directors who are independent as is required and determined in accordance with applicable laws and regulations and requirements of the NYSE.New York Stock Exchange ("NYSE"). The Board evaluates any relationships of each director and nominee with Trinseo and makes an affirmative determination whether or not such director or nominee is independent. Under our Corporate Governance Guidelines, an “independent” director is one who meets the qualification requirements for being an independent director under applicable laws and the corporate governance listing standards of the NYSE. Our Board reviews any transactions and relationships between each director or any member of his or her immediate family and Trinseo. The purpose of this review is to determine whether there were any such relationships or transactions and, if so, whether they were inconsistent with a determination that the director was independent. As a result of this review, our Board has affirmatively determined that all of our current directors and nominees, except for Mr.Messrs. Bozich and Pappas, are independent under the governance and listing standards of the NYSE. 20        2019ProxyStatement Table of Contents CORPORATE GOVERNANCE Diversity and Board Expertise. While we do not have a formal policy with respect to diversity, we believe that the diversity considerations are an important element, among many, when identifying director nominees who will best serve the needs of the Company and the interests of our shareholders. We believe diversity considerations enable us to provide sound and prudent guidance by developing a Board with a diverse range of talents, ages, skills, character, expertise, professional experiences, and backgrounds. Risk Oversight. Risk is inherent in every material business activity that we undertake. Our business exposes us to strategic, credit, market, compliance, operational and reputational risks. To support our corporate goals and objectives, risk appetite, and business and risk strategies, we maintain a governance structure that delineates the responsibilities for risk management activities, and the governance and oversight of those activities, between management and our Board. The Board is committed to 12 2017 Proxy Statement CORPORATE GOVERNANCE strong, independent oversight of management and risk through a governance structure that includes other Board committees. Under our structure, it is management’s responsibility to manage risk and bring to the Board’s attention risks that are material to Trinseo. The Board has oversight responsibility for the systems established to report and monitor the most significant risks applicable to Trinseo. The Board administers its risk oversight role directly and through its committee structure and the committees’ regular reports to the Board at Board meetings. The Board divides its risk oversight responsibilities between itself and its committees by having each review or assess key issues or areas of responsibility as follows: Board of Directors •    Strategic, financial, and execution risks and exposures associated with our annual and multi-year business plans Acquisitions and divestures •    Capital expenditure and budget planning Major litigation, investigations, and other matters that present material risk to our operations, plans, prospects, or reputation •    Acquisitions and divestures •    Senior management succession planning Audit Committee •    Risks associated with financial accounting matters, including financial reporting, accounting, disclosure, and internal controls over financial reporting Supervision and selection of our external and internal auditors •    Our ethics and compliance programs •    Related party transactions Compensation Committee •    Risks related to the design of our executive compensation programs, plans, and arrangements Senior management succession planning Nominating and Corporate Governance Committee •    Risks related to our governance structures and processes Director succession planning Environmental, Health, Safety and Public Policy Committee •    Our environmental, health and safety risk management programs •    The alignment of our environmental, health, safety, sustainability, social and public policy program with the Company’s business strategy and creation of stakeholder value Board Leadership Structure. Under our Corporate Governance Guidelines, our Board may select a Chairman of the Board of Directors at any time, who may also be an executive officer of the Company. The Board has currently chosen to separate the roles of Chairman and Chief Executive Officer. Mr. Zide, our currentnon-executive Chairman of the Board of Directors, has served as a director since 2010 and brings to the Board extensive knowledge and expertise in strategy, mergers and acquisitions. The Board believes that the separate roles of Mr. Zide and Mr. Pappas,Bozich, our Chief Executive Officer, are in the best interest of Trinseo and its 2019 Proxy Statement        21 Table of Contents CORPORATE GOVERNANCE shareholders, at this time. Mr. Zide hasin-depth knowledge of our business arising from his many years of service to Trinseo and, as a result, provides effective leadership for the Board and support for Mr. PappasBozich and other management. The structure permits Mr. PappasBozich to devote his attention to leading Trinseo and to executing on our business strategy. Board Attendance. We expect our boardBoard members to prepare for, attend and participate in all boardBoard and applicable committee meetings. Our Board held 7seven meetings in 2016.2018. The audit, compensation, and nominating and corporate governance committees held 9, 5,eight, eight, and 4five meetings in 2016,2018, respectively. No Board member attended less than 75% of our boardBoard and committee meetings, as applicable, in 2016.2018. We do not have a policy for the attendance of our directors at our annual general meeting of shareholders. We had twofour directors in attendance for our 20162018 annual general meeting of shareholders for which no shareholders attended. Under Luxembourg law we are required to receive notice by the meeting’s record date of a shareholder’s intention to attend the annual general meeting of shareholders in person. Additionally, our annual general meeting of shareholders, unless there is an exceptional circumstance, are held in Luxembourg. Executive Sessions. Our Corporate Governance Guidelines provide that thenon-management directors of the Board meet in executive session at least once during each regularly scheduled Board meeting to review matters concerning the relationship of the Board with the management directors and other members of senior management and such other matters as it deems appropriate. Additionally, the Board is required to have least one executive session annually of its independent directors. Mr. Zide acts as the chair of these executive sessions. Board Annual Performance Reviews. Pursuant to our Corporate Governance Guidelines the Board annually conducts a self-evaluation of the Board as a whole. In accordance with the written charters of our audit committee, compensation committee 2017 Proxy Statement 13 CORPORATE GOVERNANCE and nominating and corporate governance committee, we also evaluate each committee’s performance on an annual basis and report to the Board the findings. Code of Business Conduct. We have adopted a written Code of Business Conduct applicable to all directors, officers and employees and a written Code of Ethics for Senior Financial Employees, applicable to our Chief Executive Officer, Chief Financial Officer, Treasurer, Principal Accounting Officer, Controller, and all employees performing similar functions. These policies are designed to maintain the integrity of our business and financial reporting. These codes cover, among other things, professional conduct, conflicts of interest, accurate recordkeeping and reporting, public communications and the protection of confidential information, as well as adherence to laws and regulations applicable to the conduct of our business. Copies of these codes can be found under the “Corporate Governance” tab and then the “Ethics and Compliance” link on the Investor Relations section of our website,www.investor.trinseo.com. Corporate Governance Guidelines. We have adopted Corporate Governance Guidelines that outline the Board’s governance policies and practices. The current version of our Corporate Governance Guidelines can be found under the “Corporate Governance” tab and then the “Ethics and Compliance” link on the Investor Relations section of our website,www.investor.trinseo.com. Communications with Directors. Shareholders and other interested parties may communicate directly with the Board, thenon-management directors or the independent directors as a group, or specified individual directors by writing to such individual or group c/o Corporate Secretary, Trinseo S.A., 1000 Chesterbrook Boulevard, Suite 300, Berwyn, PA 19312. The Corporate Secretary will forward such communications to the relevant group or individual at or prior to the next meeting of the Board. The Board has instructed our Corporate Secretary to review the correspondence prior to forwarding it, and in his discretion, not to forward certain items if he deems them to be of a commercial or frivolous nature or otherwise inappropriate for the Board’s consideration. In these cases, he may forward some of the correspondence elsewhere in the Company for review and possible response. 22        2019ProxyStatement Table of Contents CORPORATE GOVERNANCE Luxembourg Corporate Governance.  As a Luxembourg company, we are subject to laws that can significantly restrict our Board’s ability to grant certain rights to shareholders under our articles of association.  For example, Luxembourg law: · Imposes a supermajority requirement in order to amend our articles of association, which cannot be amended by the Board or our shareholders; · Prohibits a plurality carve out from our majority voting requirement in a contested director election; and · Requires shareholder action by written consent in lieu of a meeting to be unanimous.   14 2017 Proxy Statement 2019 Proxy Statement        23 Table of Contents BOARD STRUCTURE AND COMMITTEE COMPOSITION Board Structure and Committee Composition We have a standing audit committee, compensation committee and a nominating and corporate governance committee with the composition and responsibilities described below. Each committee operates under a charter that has been approved by our Board of Directors.Board. A copy of each charter can be found by clicking on “Corporate Governance” and then “Committee Composition” in the Investor Relations section of our website,www.investor.trinseo.com. The members of each committee are appointed by the Board of Directors and each member serves until his or her successor is elected and qualified, unless he or she is earlier removed or resigns. In addition, from time to time, special committees may be established under the direction of the Board of Directors when necessary to address specific issues. The table below provides information about the membership of our standing audit, compensation, and nominating and corporate governance committees during fiscal 2016:2018: Nominating and Corporate Name Audit Compensation Governance Joseph Alvarado X Jeffrey J. Cote X* X Pierre-Marie De Leener X K’Lynne Johnson X* X Philip R. Martens X X Donald T. Misheff X X* Henri Steinmetz X Christopher D. Pappas Stephen M. Zide X X   Name    Audit     Compensation     Nominating and Corporate Governance   Jeffrey J. Cote      X *      X (1)    Pierre-Marie De Leener      X       Philip R. Martens        X (2)      X (2)  Donald T. Misheff      X         X (1)  Christopher D. Pappas          X *  Michel G. Plantevin        X     Stephen M. Zide              X *      X   * Chair (1) Mr. Cote and Mr. Misheff were appointed as members of our compensation and nominating and corporate governance committees, respectively, effective March 30, 2016. (2) Mr. Martens was appointed as a member of our compensation and nominating and corporate governance committees on September 27, 2016. *Denotes the Committee’s Chair for fiscal 2018. Ms. Johnson replaced Mr. Zide as compensation committee chair effective February 2019. Audit Committee The purpose of the audit committee is set forth in the audit committee charter. The audit committee’s primary duties and responsibilities are to: · Appoint or replace, compensate and oversee the outside auditors for the purpose of preparing or issuing an audit report or related work or performing other audit, review or attest services for us and will report directly to the audit committee. · Pre-approve all auditing services and permitted non-audit services (including the fees and terms thereof) to be performed for us by our outside auditors, which are approved by the audit committee prior to the completion of the audit. · Review and discuss with management and the outside auditors the annual audited and quarterly unaudited financial statements, our disclosures under “Management’s Discussion and Analysis of Financial Condition and Results of Operations”, and the selection, application and disclosure of critical accounting policies and practices used in such financial statements. · Review and approve all related party transactions as defined under Item 404(a) of Regulation S-K. · Discuss with management and the outside auditors significant financial reporting issues and judgments made in connection with the preparation of our financial statements, including any significant changes in our selection or application of accounting principles, any major issues as to the adequacy of our internal controls and any special steps adopted in light of material control deficiencies. Appoint or replace, compensate and oversee the outside auditors for the purpose 24        2019ProxyStatement Table of preparing or issuing an audit report or related work or performing other audit, review or attest services for us and will report directly to the audit committee.Contents BOARD STRUCTURE AND COMMITTEE COMPOSITION Pre-approve all auditing services and permittednon-audit services (including the fees and terms thereof) to be performed for us by our outside auditors, which are approved by the audit committee prior to the completion of the audit. Review and discuss with management and the outside auditors the annual audited and quarterly unaudited financial statements, our disclosures under “Management’s Discussion and Analysis of Financial Condition and Results of Operations”, and the selection, application and disclosure of critical accounting policies and practices used in such financial statements. Review and approve all related party transactions as defined under Item 404(a) ofRegulation S-K. Discuss with management and the outside auditors significant financial reporting issues and judgments made in connection with the preparation of our financial statements, including any significant changes in our selection or application of accounting principles, any major issues as to the adequacy of our internal controls and any special steps adopted in light of material control deficiencies. A copy of the charter, which satisfies the applicable standards of the Securities and Exchange Commission (the “SEC”) and the NYSE is available on our website.website,  www.trinseo.com. The audit committee currently consists of Donald T. Misheff, Joseph Alvarado, Jeffrey J. Cote, and Pierre-Marie De Leener.Leener, and Donald T. Misheff. Our Board has determined that each of Messrs. Misheff,Alvarado, Cote, and De Leener and Misheff are independent directors pursuant to Rule 10A-3(b)10A‑3(b)(1) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and Section 303A.02 of the New York Stock Exchange Listed Company Manual. Each of Messrs. MisheffCote and CoteMisheff is also an “audit committee financial expert” within the meaning of Item 407(d)(5) ofRegulation S-K. Mr. Cote also serves as chair of the audit committee. 2017 Proxy Statement 15 BOARD STRUCTURE AND COMMITTEE COMPOSITION Compensation Committee Compensation Committee The purpose of the compensation committee is to assist the Board in fulfilling its responsibilities relating to oversight of the compensation of our directors, executive officers and other employees and the administration of our benefits and equity-based compensation programs. The compensation committee reviews and recommends to our Board compensation plans, policies and programs and approves specific compensation levels for all executive officers. The compensation committee currently consists of Jeffrey J. Cote, K’Lynne Johnson, Philip R. Martens, and Stephen M. Zide. Messrs. Cote and Martens and Ms. Johnson joined the compensation committee in March 2016, September 2016, and April 2017, respectively. Mr. Zide serves as chair of the compensation committee. A copy of its charter, which satisfies the applicable standards of the SEC and the NYSE, is available on our website.website,  www.trinseo.com. Pursuant to its charter, the compensation committee may delegate to subcommittees of the compensation committee any of the responsibilities of the full committee. Nominating and Corporate Governance Committee The purpose of the nominating and corporate governance committee is to (i) identify, screen and review individuals qualified to serve as directors (consistent with criteria approved by our Board) and recommend to our Board candidates for nomination for election at the annual meeting of shareholders or to fill Board vacancies or newly created directorships; (ii) develop and recommend to our Board and oversee the implementation of our corporate governance guidelines; (iii) oversee evaluations of our Board and (iv) recommend to our Board candidates for appointment to board committees. The nominating and corporate governance committee currently consists of K’Lynne Johnson, Philip R. Martens, Donald T. Misheff, Henri Steinmetz, and Stephen M. Zide. Messrs. Misheff and Martens joined the nominating and corporate governance committee in March 2016 and September 2016, respectively. Ms. Johnson joined the nominating and corporate governance committee in April 2017. Mr. Misheff serves as chair of the nominating and corporate governance committee. Our Board has adopted a written charter under which the nominating and corporate governance committee operates. A copy of the charter is available on our website.website,  www.trinseo.com. Compensation Committee Interlocks and Insider Participation None of our executive officers serves as a member of the board of directors or the compensation committee of any other company that has any executive officers serving as a member of our Board or compensation committee.   16 2017 Proxy Statement 2019 Proxy Statement        25 Table of Contents OUR COMPANY’S EXECUTIVE OFFICERS Our Company’s Executive Officers Biographical information concerning our President and Chief Executive Officer, Christopher D. Pappas,Frank A. Bozich, who also serves as a member of our board of directors,Board, is set forth above under Proposal 1—Election of Class III Director.1. Barry J. Niziolek,David P. Stasse,Executive Vice President and Chief Financial Officer. Officer. Mr. Niziolek,Stasse, age 61, became48, joined the Company’s Chief Financial OfficerCompany in June 2016. From September 2006 through August 2015, Mr. Niziolek was aJuly 2013 as Vice President and Controller at E.I. DuPont de Nemours &Treasurer with responsibility for all treasury matters, including cash management, risk management, relationships with rating agencies and commercial banks, and financing matters. Mr. Stasse assumed his current position with the Company (“DuPont”)in July 1, 2019. Mr. Stasse joined the Company from Freescale Semiconductor, Inc., a global semiconductor manufacturer that serves the automotive, networking, consumer and industrial markets, where he was responsible forserved as Vice President and Treasurer since July 2008. Mr. Stasse holds a MBA in Finance from the company’s accounting controls, financial reporting,University of Maryland and financial planning and analysis. During his 34 years at DuPont, he held a wide rangeBachelor of finance roles, including as chief financial officer for the titanium and coatings businesses, as well as chief financial officer for the crop protection business. At DuPont, Mr. Niziolek acquired substantial experience in finance leadership, governance and compliance, board interactions, mergers and acquisitions, risk management, capital structure, corporate planning, new business development, and investor relations. Mr. Niziolek began his career at KPMG, where he was a senior auditor. Mr. Niziolek has a bachelor of scienceScience degree in accountingBusiness Logistics from Wilkes University and his MBA from University of Delaware. He is a certified public accountant.Penn State University. Timothy M. Stedman, Senior Vice President, Corporate Development and Business President, Feedstocks, Plastics and Global Integrated Business Services.Strategy Mr. Stedman, age 47,49, joined the Company as Senior Vice President and Business President, Basic Plastics & Feedstocks, in November 2015. In this role, he was responsible for business leadership for polystyrene,co-polymers, polycarbonate, and styrene monomer. In his current role, which began in October 2017, Mr. StedmanStedman’s role changed and he also became responsible for the Company’s performance plastics business. As part of histhis role, he servesserved as a member of the operating committee of the Plastics Division of the American Chemistry Council. On October 7, 2019, Mr. Stedman’s role changed to Senior Vice President, Corporate Development and Strategy. In his current role, Mr. Stedman is responsible for mergers and acquisition strategy and implementation.  Prior to joining the Company, Mr. Stedman spent more than 20 years with ExxonMobil Chemical working in the U.K., the U.S., and Belgium. Most recently, Mr. Stedman was the Europe Business Director for ExxonMobil Chemical’s Basic Chemicals business, and prior to that was the Site Manager for the Fife Ethylene Plant (steam cracker) in Scotland. Mr. Stedman also led Global Sales and Marketing organizations for several ExxonMobil Chemical’s Polymers and Intermediates businesses, including the Santoprene business that was formally part of the Advanced Elastomers Systems joint venture with Monsanto. Mr. Stedman currently serves on the boards of PlasticsEurope, a trade association for plastics manufacturers, and the American Chemistry Council – Plastics Division. Mr. Stedman previously served on the boards of Petrochemicals Europe and the European Petrochemical Association until September 2015 and was also a member of the Energy and Climate Change Leadership Group of the International Council of Chemical Associations (ICCA). Mr. Stedman holds a degree in Chemical Engineering and French from the University of Manchester Institute of Science and Technology, U.K., and the EcoleÉcole Nationale Supérieure des Industries Chimiques, Nancy, France. He is also a Chartered Engineer and a Fellow of the Institute of Chemical Engineers (U.K.). Hayati Yarkadas, Senior Vice President and Business President, Latex Binders, Synthetic Rubber and Global Procurement. Mr. Yarkadas, age 49, joined the Company in November 2015 to lead the rubber, latex, and performance plastics businesses. Since October 2017, Mr. Yarkadas now leads the latex binders and synthetic rubber businesses, along with the global procurement function and leadership of the Asia Pacific region. Mr. Yarkadas has more than 20 years of experience in the materials business. From July 2013 to November 2015, Mr. Yarkadas led the food ingredient business of Tate & Lyle in Europe as Senior Vice President and General Manager, based in London. Prior to that, Mr. Yarkadas spent over 17 years with DuPont in many of its worldwide locations. Most recently Mr. Yarkadas served as General Manager of the DuPont Teijin Films joint venture from May 2009 to May 2013. Previously, he was Global Business Director for DuPont Advanced Glass Interlayers and held a series of roles in sales, sales management, Six Sigma, marketing, product management and business management in plastics and chemicals. Throughout his career, Mr. Yarkadas gained significant operating and global leadership skills with various roles in Turkey, the U.K., Switzerland, the U.S., and Luxembourg. Mr. Yarkadas has a master’s degree in Mechanical Engineering from Istanbul Technical University and an MBA from Imperial College London. Angelo N. Chaclas, Senior Vice President, Chief Legal Officer, and Corporate Secretary.Mr. Chaclas, age 54,56, has been the Company’s Chief Legal Officer, Senior Vice President, and Corporate Secretary since January 2015. In his role, he provides legal support for all capital markets, transactional, compliance, commercial, regulatory, governance, intellectual property and other operational activities of the Company worldwide. Mr. Chaclas joined the Company in 2010 as Associate General Counsel and Chief Intellectual Property Counsel, where he managed the Company’s global intellectual property portfolio and supported the legal activities of several of the Company’s commercial businesses. Prior to joining the Company in 2010, Mr. Chaclas was Deputy General Counsel and Chief Counsel for the software division of Pitney Bowes where he led its Intellectual Property, Technology Law and Procurement legal functions. Mr. Chaclas holds a bachelor’s degree in Mechanical Engineering from Tufts University and a Juris Doctorate from Pace University. Marilyn N. Horner, Senior Vice President—Human Resources. Ms. Horner, age 59, joined the Company as Alice Heezen,  Senior Vice President, Human Resources.  Ms. Heezen, age 49, became the Company’s Senior Vice President, Human Resources in April 2018 after joining the Company in January 2017 as Director of Human Resources in January 2011.for Europe, Middle East, and Africa region. Prior to joining the Company, Ms. Horner held a numbershe was Head of executive positions at NOVA 26        2019ProxyStatement Table of Contents 2017 Proxy Statement 17 OUR COMPANY’S EXECUTIVE OFFICERS Chemicals where she started her career in 1988. She served as the Senior Vice President and Chief Human Resources Officer for NOVA ChemicalsADAMA Agricultural Solutions Europe from 2008July 2013 to December 2010.2016. Ms. HornerHeezen has also held the positions of Vice President Financesenior HR leadership roles at Fiberweb Plc, a London listed global specialty industrial and Controller, Olefins / Polyolefins Division; Vice President Human Resourcesconstruction materials business from 2010 to 2013; BG Group, a global oil and gas company, from 2005 to 2009; and REXAM Plc, a global consumer packaging company, from 2001 to 2005. Ms. Heezen holds a master’s degree in Social and Organizational Effectiveness; and Vice President to the Chief Executive Officer. Ms. Horner holds a Bachelor of Commerce degree and an MBAPsychology from the University of Windsor in Ontario, Canada.Leiden, The Netherlands. E. Jeffery Denton, Senior Vice President—Corporate Development and BusinessSupply Chain Services.Mr. Denton, age 52,54, joined the Company as Vice President—Shared Services and Feedstocks in June 2010 and was named Vice President—Corporate Development and Business Services in October 2014, and subsequently Senior Vice PresidentPresident—Corporate Development and Business Services in October 2015. In October 2019, Mr. DentonDenton’s role changed to Vice President—Supply Chain Services. In this role, he is responsible for the Company’s  Procurement, Information Technology and Corporate DevelopmentSupply Chain functions. He previously served in a similar role with respect to the Procurement and Supply Chain functions at the Company (when it was a division of Dow) from September 2009 until June 2010 and as the Director of Joint Venture Implementation at Dow from February 2006 until September 2009.Company. Mr. Denton received a bachelor’s degree in Business Administration from Alma College. Catherine C. Maxey,Keenan, Vice President—Public Affairs, Sustainability and Environment, Health and Safety.Ms. Maxey,Keenan, age 51,53, joined the Company as Vice President—Public Affairs and Business Intelligence in June 2010. Previously she held positions of increasing responsibility at Dow, which she joined in 1988, most recently as Public Affairs director for Mergers & Acquisitions, Joint Ventures, Dow Portfolio Optimization/Divestitures and Manufacturing and Engineering from March 2009 until June 2010. She also served as Dow’s Business Public Affairs Director for Performance Chemicals from 2003 to June 2008. Ms. MaxeyKeenan received a bachelor’s degree in Journalism/Science Writing from Lehigh University. David P. Stasse, Vice President—Treasury and Corporate Finance. Mr. Stasse, age 47, joined the Company in July 2013 as Ryan Leib, Vice President and TreasurerTreasurer. Succeeded Dave Stasse in July 2019. Mr. Leib, age 42, joined Trinseo in August of 2013 as Assistant Controller and was promoted to Corporate Controller in 2014. In 2017, he was promoted to Vice President, Global Controller, and Principal Accounting Officer. Leib has led the Company’s global consolidation, accounting policies and procedures, internal controls compliance to comply with the Sarbanes-Oxley act (SOX), certified our financial filings with the U.S. SEC, and was the primary liaison with Trinseo’s Audit Committee.   Prior to joining Trinseo, Mr. Leib was a senior manager with PricewaterhouseCoopers LLP, where he spent 13 years providing auditing and accounting services to large multinational public companies. During his time with PwC, he also spent two years in their national office providing client companies with technical guidance on complex accounting issues. He has his bachelor’s degree in accounting from St. Joseph’s University and is a Certified Public Accountant (CPA). Tim Thomas, Vice President—Manufacturing and Operational Excellence. Mr. Thomas, age 53, has been with the Company since its inception and has previously held positions of increasing responsibility related to the Company’s manufacturing operations, including Global Business Manufacturing Leader—Latex and Operations Director—Performance Materials.  As of October 7, 2019, Mr. Thomas’ role changed to a newly created role, Vice President—Manufacturing and Operational Excellence. In this role, he has responsibility for all treasurymanufacturing operations globally, including all production sites and investor relations matters, including cash management, risk management, relationships with rating agenciesplants, technical centers, quality, engineering, process automation, process safety, maintenance and commercial banks, and financing matters. Mr. Stasse joined the Company from Freescale Semiconductor, Inc., a global semiconductor manufacturer that serves the automotive, networking, consumer and industrial markets, where he served as Vice President and Treasurer since July 2008, and Assistant Treasurer from August 2006 to July 2008. Mr. Stasse holds a MBA in Finance from the University of Maryland and a Bachelor of Sciencereliability.  He has his bachelor’s degree in Business LogisticsChemical Engineering from PennYoungstown State University.   18 2017 Proxy Statement 2019 Proxy Statement        27 Table of Contents TRANSACTIONS WITH RELATED PERSONS Transactions with Related Persons Certain Relationships and Related Transactions Our Conflict of Interest Policy is designed to help our directors, executive officers, and employees address situations that may involve a conflict of interest, which may include related party transactions. These include situations in which an individual’s personal interests are in conflict with the interests of the Company; situations in which an individual or family member receives personal benefits as a result of his or her position with the Company; and situations that may otherwise cast doubt on his or her ability to act objectively with or on behalf of the Company. The Company annually surveys our executive officers and directors regarding potential conflicts of interest. If such conflicts are reported or found, the Legal Department and/or our Chief Compliance Officer will seek to mitigate or eliminate such potential or actual conflictconflicts of interest. Our audit committee charter requires that the audit committee review and approve all related party transactions. The Company also has a written related parties policy. When related party transactions between us and our officers, directors and principal shareholders and their affiliates, are approved by the audit committee, it does so with the understanding that the terms of such transaction are no less favorable to us than those that we could obtain from unaffiliated third parties. Share Repurchase and Secondary Offerings   On March 24, 2016, our former Parent, Bain Capital Everest Manager Holding SCA, sold an aggregate 28        2019ProxyStatement Table of 10,600,000 of our ordinary shares in a registered, underwritten public offering to Goldman, Sachs & Co. (the “Underwriter”). Concurrent with that offering, the Company repurchased a total of 1,600,000 of our ordinary shares from the Underwriter at a price of $35.63 per share, the same price per share paid by the Underwriter. As a result of the share repurchase, our former Parent received approximately $57,008,000 in proceeds from the Company. Five of our directors at that time, Messrs. Zide, Thomas, Plantevin, Hauser, and Vasseur, were affiliated with our former Parent. Therefore, the decision to repurchase 1,600,000 of our shares at $35.63 was delegated to a committee of disinterested directors consisting of our audit committee members.Contents During the year ended December 31, 2016, our former Parent also sold 37,269,567 ordinary shares pursuant to the Company’s shelf registration statement filed with the SEC. In connection with these secondary offerings, the Company incurred advisory, accounting, legal and printing expenses on behalf of the former Parent of $2.5 million during the year ended December 31, 2016. The Company was obligated to pay these expenses under a June 17, 2010 registration rights agreement entered into with our former Parent at the time of our Company’s formation. These expenses were included within “Selling, general and administrative expenses” in the Company’s 2016 consolidated statement of operations contained in its 2016 Annual Report onForm 10-K. During the period of these transactions, six of our directors, Messrs. Zide, Thomas, Plantevin, Hauser and Vasseur and Ms. Springham, were affiliated with our former Parent. 2017 Proxy Statement 19 STOCK OWNERSHIP INFORMATION Stock Ownership Information The following table sets forth information regarding the beneficial ownership of our ordinary shares, nominal value $0.01, as of October 17, 201718,  2019 by: · each person or group of affiliated persons known by us to be the beneficial owner of more than 5% of our ordinary shares; · each of our named executive officers, director nominees and directors; and · each person or group of affiliated persons known by us to be the beneficial owner of more than 5% of our ordinary shares; each of our named executive officers, director nominees and directors; and all of our directors, director nominees and executive officers as a group. As of October 17, 2017,18, 2019, we had 43,703,31439,280,112 ordinary shares outstanding (excluding treasury shares), all of which were held by public investors (including certain of our directors and executive officers), the details of which are reflected in the table below. Information with respect to beneficial ownership has been furnished by each director, director nominee, executive officer or beneficial owner of more than 5% of our ordinary shares. We have determined beneficial ownership in accordance with SEC rules. These rules generally attribute beneficial ownership of shares to persons who possess sole or shared voting or investment power with respect to such shares. The information does not necessarily indicate beneficial ownership for any other purpose. Under these rules, the number of shares of ordinary shares deemed outstanding includes shares issuable upon exercise of options and held by the respective person or group which may be exercised or converted within 60 days after October 17, 2017.18, 2019. These shares are deemed to be outstanding and beneficially owned by the person holding those options for the purpose of computing the percentage ownership of that person or entity, but they are not treated as outstanding for the purpose of computing the percentage ownership of any other person or entity. Mr. Pugh has been excluded from the table since he is no longer required to file reports with the SEC for all of his equity transactions due to his March 1, 2017 retirement. As of March 1, 2017, Mr. Pugh held 83,880 shares, which included 56,151 vested options. Unless otherwise indicated below, the address for each listed director, director nominee, executive officer and shareholder is c/o Trinseo S.A., 1000 Chesterbrook Boulevard, Suite 300, Berwyn, Pennsylvania 19312. The inclusion in the following table of those shares, however, does not constitute an admission that the named shareholder is a direct or indirect beneficial owner. Unless otherwise indicated and subject to applicable community property laws, to our knowledge, each shareholder named in the following table possesses sole voting and investment power over the shares listed, except for those jointly owned with that person’s spouse. 2019 Proxy Statement        29 Table of Contents STOCK OWNERSHIP INFORMATION               Number of         Shares of   Percent Name      Company      of Class(1) M&G Investment Management Limited(2)   6,574,844    16.7% Boston Partners(3)   4,278,233    10.9% BlackRock, Inc.(4)   6,086,170    15.5% LSV Asset Management(5)   2,365,886    6.0% Christopher D. Pappas(6)   477,661    1.2% Barry J. Niziolek(7)   43,953    * Timothy M. Stedman(8)   32,563    * Hayati Yarkadas(9)   39,161    * Angelo N. Chaclas(10)   37,885    * Joseph Alvarado   3,397    * Jeffrey J. Cote   12,833    * Pierre-Marie De Leener   10,694    * K’Lynne Johnson   3,427    * Philip R. Martens    4,916    * Donald T. Misheff    8,241    * Henri Steinmetz   1,355    * Stephen M. Zide    28,327    * Frank A. Bozich   15,000    * Sandra Beach Lin   —    * Mark Tomkins   2,800   * All Directors, Nominees and Executive Officers as a Group (20 persons)(11)   728,698    1.9% *       Indicates less than one percent. (1) The ownership percentages set forth in this column are based on the Company’s outstanding ordinary shares (excluding treasury shares) as of October 18, 2019 and assumes that each of the beneficial owners continued to own the number of shares reflected in the table on such date. Name (2) Number On February 5, 2019, M&G Investment Management Limited ("M&G Investment") filed Schedule 13G with the SEC reporting beneficial ownership of Shares 6,574,844 of Company Percentage our ordinary shares as of December 31, 2018, with sole voting power and sole dispositive power over such shares. The address of M&G Investment is Governor’s House, Laurence Pountney Hill, London, EC4R OHH. Management (3) On January 9, 2019, Boston Partners filed Schedule 13G with the SEC reporting beneficial ownership of 4,278,233 of our ordinary shares as of December 31, 2018, with sole voting power over 3,299,956 shares, shared voting power over 4,654 shares, and sole dispositive power over 4,278,233 shares. The address of Boston Partners is One Beacon Street, 30th Floor, Boston, MA 02108. Christopher D. Pappas(1) 32,733 * Barry J. Niziolek(2) 9,134 * Timothy M. Stedman 2,111 * Hayati Yarkadas(3) 9,610 * Joseph Alvarado — * Jeffrey J. Cote 9,422 * Pierre-Marie De Leener 7,894 * K’Lynne Johnson — * Philip R. Martens 1,505 * Donald T. Misheff 4,844 * Henri Steinmetz — * Stephen M. Zide 4,930 * All Directors, Nominees and Executive Officers as a Group (18 persons)(4) 115,091 * On September 10, 2019, BlackRock, Inc. filed Schedule 13G with the SEC reporting beneficial ownership of 6,086,170 of our ordinary shares as of August 31, 2019, with sole voting power over 5,975,229 shares and sole dispositive power over 6,086,170 shares. The address of BlackRock, Inc. is 55 East 52nd Street, New York, NY 10055. * Indicates less than one percent. (5) On February 13, 2019, LSV Asset Management filed Schedule 13G with the SEC reporting beneficial ownership of 2,365,886 of our ordinary shares as of December 31, 2018, with sole voting power over 1,421,661 shares and sole dispositive power over 2,365,886 shares. The address of LSV Asset Management is 155 N. Wacker Drive, Suite 4600, Chicago, IL 60606. (1) (6) The number of shares of the Company includes 22,733332,451 vested options. (2) The number of shares of the Company consists of 9,134 vested options. (7) (3) The number of shares of the Company includes 7,51039,453 vested options. (4) (8) The number of shares of the Company includes 66,08523,433 vested options. (9) 20 2017 Proxy Statement The number of shares of the Company includes 30,943 vested options. (10) The number of shares of the Company includes 24,113 vested options. (11) The number of shares of the Company includes 430,531 vested options. SECTION 16(A) BENEFICIAL OWNERSHIP REPORTING COMPLIANCE   30        2019ProxyStatement Table of Contents Equity Compensation Plan Information Equity Compensation Plan Information The following table sets forth certain information as of December 31, 2018 with respect to compensation plans under which ordinary shares of the Company may be issued.                     Number of securities to   Weighted-average   Number of securities remaining     be issued upon exercise   exercise price of   available for future issuance under     of outstanding options,   outstanding options,   equity compensation plans  (excluding        warrants and  rights      warrants and rights      securities reflected in column (a)) Plan Category   (a)   (b)   (c) Equity compensation plans approved by securityholders   1,542,849  (1) $ 46.72  (2) 1,882,247  Equity compensation plans not approved by securityholders   —      —    —  Total   1,542,849    $ 46.72    1,882,247  (1) Includes 492,149 restricted stock units, 116,362 performance award stock units, and 934,338 options to purchase shares that have been granted under the approved Trinseo S.A. 2014 Omnibus Incentive Plan and remain outstanding as of December 31, 2018. The restricted stock units and performance stock units will result in the issuance of shares immediately upon vesting, with the vesting of performance stock units subject to the Company’s relative TSR performance. The options to purchase shares will result in securities to be issued upon exercise. (2) Represents the weighted-average exercise price of the above-mentioned options to purchase shares only.  The Company’s performance award stock units and restricted stock units do not have associated exercise prices. Section 16(a) Beneficial Ownership Reporting Compliance Section 16(a) of the Securities Exchange Act of 1934, as amended, requires our directors,  and executive officers, beneficial owners of more than 10% of our ordinary shares, among others (the “reporting persons”), to file with the SEC an initial report of ownership of our stock on a Form 3 and reports of changes in ownership on a Form 4 or a Form 5. Persons subject to Section 16 are required by SEC regulations to furnish us with copies of all Section 16(a) forms that they file. Under SEC rules, certain forms of indirect ownership and ownership of company stock by certain family members are covered by these reporting requirements. When requested, we assist our executive officers and directors in preparing initial ownership reports and reporting ownership changes and will file these reports on their behalf. Based solely on a review of Forms 3, 4 and 5 filed with the copies of such forms in our possession,SEC and onany written representationsrepresentation from our current directors and executive officers,the reporting person that no Form 5 is required, we believe all of our executive officers and directorsthe reporting persons filed the required reports on a timely basis under Section 16(a) during 2016.2018.     2017 Proxy Statement 21 2019 Proxy Statement        31 Table of Contents COMPENSATION DISCUSSION AND ANALYSIS Compensation Discussion and Analysis This compensation discussion and analysis (CD&A) section is intended to provide information about our 20162018 compensation objectives and programs for our named executive officers. For 2016,2018, our named executive officers, or NEOs, were:   Name Position Christopher D. Pappas President and Chief Executive Officer Martin Pugh*Officer* Executive Vice President and Chief Operating Officer Barry J. Niziolek Executive Vice President and Chief Financial OfficerOfficer** Timothy M. Stedman Senior Vice President and Business President Basic Plastics and Feedstocks Hayati Yarkadas Senior Vice President and Business President Performance Materials Angelo N. Chaclas Senior Vice President, Chief Legal Officer, Chief Compliance Officer and Corporate Secretary   * Mr. Pugh retired from the Company effective March 1, 2017. *Mr. Pappas retired from his position as President and Chief Executive Officer effective March 4, 2019 at which time Mr. Bozich assumed this role. Mr. Pappas was still employed as a Special Advisor to the Chief Executive Officer until his retirement on May 3, 2019. **Mr. Niziolek retired from his position as Executive Vice President and Chief Financial Officer effective July 1, 2019 at which time Mr. Stasse assumed this role. This CD&A is divided into the following sections: · Executive Summary · Compensation Philosophy and Design · How We Make Compensation Decisions · 2018 Compensation Structure & Performance · Executive Summary Compensation Philosophy and Design How We Make Compensation Decisions 2016 Compensation Structure & Performance Other Compensation and Tax Matters Executive Summary Business Performance Business Achievements We had record financial performancefinished 2018 with lower than anticipated profitability due to challenging market dynamics and economic conditions toward the end of the year, particularly in 2016, which included steady improvement withinNovember and December. Despite this, the Company delivered strong cash generation throughout 2018 and returned significant cash to our Performance Materials division,shareholders, purchasing approximately 2.2 million ordinary shares for an aggregate purchase price of $142.9 million and declaring quarterly dividends for an aggregate value of $1.56 per ordinary share, or $67.2 million.  We continue to prioritize sustainability as well as record results fromdemonstrated by another strong year for our Basic Plastics & Feedstocks division. Our results reflected our continued efforts on investing in growth areas, reducing costs through streamlining our portfolio and asset footprint, generating cash, and improving our net leverage and reducing interest expense. We also had record environmental, health and safety performance as measured by our Responsible Care® program goals, with zerono process safety incidents and only two spills and four recordable injuries. As a result the annual cash incentive plan bonuses paid to our NEOs ranged from approximately 144% to 150% of the target bonus amount.spills. Consideration of 20162018 Advisory Vote on Executive Compensation The compensation committee regularly reviewsOver the philosophy, objectivespast three years, our Board members supported by our investor relations and elements oflegal functions have conducted meaningful engagement and dialogue regarding our executive compensation programs in relationand corporate governance practices. Through these engagements, we have heard from a substantial proportion of our shareholders and learned a great deal. We consider the insights we receive from this feedback and the results of our annual advisory say-on-pay proposal to our short- and long-term business objectives. As part of this review,be a critical component to the compensation committee considerscommittee’s design and oversight of the views of shareholders as reflected in their annual advisory vote on ourCompany’s executive compensation proposal. At our 2016 annual general meetingprograms.  We continually evaluate 32        2019ProxyStatement Table of shareholders, our executive compensation proposal received support from approximately 83.4% of the votes cast. We continue to evaluate Contents COMPENSATION DISCUSSION AND ANALYSIS opportunities to enhance our compensation programs to attract top talent and provide further alignment with the interests of our shareholders. In 2016At the 2018 Annual General Meeting of Shareholders, our advisory shareholder vote on executive compensation received less than majority support from our voting shareholders, with only 44% of the votes cast in favor of our advisory executive compensation proposal.  This marked a significant change from the prior year where our advisory executive compensation proposal received support from approximately 96% of the votes cast.  While the compensation committee believed that the Company’s executive compensation programs had been effective in achieving the Company’s compensation philosophy and objectives, our shareholders disagreed. Based on the engagement with our shareholders ahead of the 2018 Annual General Meeting and the feedback from the proxy advisory firms, we adoptedlearned that the primary objection to our compensation programs was the historical 280G gross-up provision that remained in Mr. Pappas’ employment agreement, which had been amended in 2017. During 2018, we amended Mr. Pappas’ employment agreement to remove the historical 280G gross-up provision.  No other executives besides Mr. Pappas had a clawback policy that allows incentive-based280G gross-up provision in their employment agreement, nor have any of our other executives had such a provision in their employment agreement since our formation. The compensation committee further reinforced its commitment to be clawed backdiscontinue the provision of these gross-ups in the Company’s executive employment agreements by excluding any such provision in the Company’s employment agreement with its new Chief Executive Officer and President, Mr. Bozich. To further understand our shareholders’ concerns reflected in our 2018 say-on-pay results and our shareholders’ reception to the extent it was awarded on the achievement of financial results that become subject to an accounting restatement that should have resultedactions taken thus far in the executive receiving a lower amount of compensation had our financial results been properly reported. See “Compensation Philosophy and Design—Maintaining Best Practices Regarding Executive Compensation.” For 2017, we have also changedresponse, our compensation programcommittee chair, along with certain members of management, initiated further shareholder outreach during the first quarter of 2019.  These efforts included reaching out to put a greater focus onat-risk, long-term incentive-based compensation by including performance award stock units (“PSUs”) as a componentshareholders representing approximately 71% of our executives’ target equity compensation. Executive target equity compensation will now be delivered inoutstanding shares. Shareholders representing approximately 50% of the form of stock options (30%), restricted stock units (30%),Company’s outstanding shares responded to our outreach efforts and PSUs (40%). We believe the addition of PSUs, along with providing a higher concentration of equity compensation in PSUs over the other equity compensation components, will provide greater alignment betweenagreed to have discussions about our executive compensation programprograms. Shareholders accepting an invitation for a discussion were each offered the opportunity to speak with a compensation committee member. However, most shareholders declined this opportunity and the creation of shareholder value throughdiscussed their concerns with the Company’s long-term strategic initiatives.investor relations representatives directly.   The balance of our shareholders contacted declined our invitation to speak with management or compensation committee members or did not respond to our request for a discussion. We believe at least some of the shareholders who declined the opportunity to engage did so because they do not have ongoing or significant concerns with the current design of our executive compensation programs. These discussions were helpful in deepening our understanding of the expectations of our investors regarding the design and disclosure surrounding our executive compensation programs. From these discussions, we confirmed that a significant portion of our shareholders are satisfied with our executive compensation programs and philosophy in light of the actions we have taken in response to our most recent say-on-pay results. 22 2017 Proxy Statement Our compensation committee appreciated this feedback and used these discussions as an opportunity to more fully explain its compensation philosophy and decisions. These discussions will continue to influence the compensation committee’s decision process with respect to the design and disclosure of its executive compensation programs, along with influencing our nominating and corporate governance committee and Board regarding its decision processes surrounding our governance and sustainability practices and disclosures going forward. 2019 Proxy Statement        33 Table of Contents COMPENSATION DISCUSSION AND ANALYSIS The PSUs will vest on the third anniversary of the grant date, subject to the Company’s relative total shareholder return (“TSR”) performance, assuming the reinvestment of dividends, against the performance of 59 other chemical companies with shares traded on a major U.S. stock exchange and have a market capitalization exceeding $500 million dollars at the time the award is granted. The amount of PSUs that will vest are generally as follows: Trinseo Percentile Ranking Relative to Peer Group % of Target Shares Vested*  Under 25th percentile 0%  25th percentile 50%  50th percentile 100%  75th percentile 200%  * Vesting is interpolated between the 25th and 50th and between the 50th and 75th percentiles Regardless of the targets above vesting will be capped at 100% of target if the Company’s TSR is negative for the performance period. Additionally, the total value of the awards delivered at vesting is capped at three times the target shares multiplied by the grant date share price. Because we assume reinvestment of dividends, dividend equivalents will accrue during the performance period. However, dividend equivalents will be paid only if and to the extent the PSUs vest, since we do not believe the executives should receive the benefit of such dividend earnings if the performance criteria associated with the PSU award is otherwise not met. Beginning in 2016, our Board began changing the composition of the compensation committee and has added additional members from its newly appointed directors. We believe the new composition will provide a fresh perspective on compensation matters. Compensation Philosophy and Design Overview Our executive compensation policies and programs are designed to attract, retain and motivate key executives through competitive and cost effective programs that reinforce executive accountability and reward the achievement of business and individual results. Executive compensation consists of four main elements: (1) base salary, (2) annual cash incentive awards, (3) long-term incentive compensation, and (4) retirement savings and benefit programs. The relative weighting of each element is aligned with our philosophy of linking pay to performance. A substantial percentage of our executives’ compensation is provided in the form of performance-based variable compensation with a greater emphasis on variable components for our senior executives. Annual cash awards are directly linked to corporate results and short-term performance measures, including financial andnon-financial goals. Our equity incentive awards align our executives’ interestinterests with those of our shareholders and our long-term business objectives. Executive retirement and benefits programs are generally consistent with the broader employee programs offered in the country where an executive primarily provides services to the Company. We provide limited perquisites to our executives and senior management, and such perquisites are only provided to the extent that they reflect particular business needs and objectives. We strive to provide our NEOs with a compensation package that is market competitive within our industry and recognizes and rewards superior individual and company performance. 2017 Proxy Statement 23 COMPENSATION DISCUSSION AND ANALYSIS Compensation Mix The chart below shows the 20162018 target mix of compensation between salary and short- and long-term incentive compensation for Mr. Pappas and our other NEOs as a group. Long-term incentive compensation remains the largest component of our NEOs’ compensation in order to incentivize long-term value creation and to provide continued alignment between the interests of our NEOs and shareholders.   CEO Target Compensation Average Target Compensation for All Other NEOS Maintaining Best Practices Regarding Executive Compensation Our compensation committee intends to compensate our NEOs in a manner that is consistent with the objectives and design principles outlined above. We have adopted the following compensation practices, which are intended to promote strong corporate governance and alignment with shareholdershareholder’s interests: 34        2019ProxyStatement Table of Contents COMPENSATION DISCUSSION AND ANALYSIS Compensation Committee Practices   Clawback and Recoupment Policies We have the right to clawbackclaw back incentive-based compensation to the extent it was awarded on the achievement of financial results subject to an accounting restatement that should have resulted in the executive receiving a lower amount of compensation had our financial results been properly reported. The Company’s board of directors can recoup this compensation by requiring the reimbursement of compensation previously paid, cancelling outstanding vested or unvested equity awards, or taking any other action permitted by law. Our equity award agreements also provide for the recoupmentreimbursement of all or part of any annual incentive compensation if there is a breach by the executive of his award agreement or anynon-competition,non-solicitation, confidentiality or similar covenant or agreement with us or an overpayment of incentive compensation due to inaccurate financial data. Share Ownership GuidelinesRequirements The compensation committee has adopted share ownership guidelinesrequirements (i) equal to six times base salary for the CEO, and (ii) equal to two times base salary for our other NEOs. The guideline must be achieved by January 1, 2021, or for newly hired executives 5 years from their hire date. Until the guidelineownership requirement is met, the executive must retain as a holding requirement: (i) 50% of the shares issued after vesting and settlement of restricted stock units (“RSUs”) (shares net of all applicable taxes), and (ii) 50% of the shares issued following the exercise of a stock option or the vesting and settlement of performance stock units (“PSUs”) (after satisfaction of the exercise price and net of all applicable taxes and full cost to exercise)exercise, as applicable). 24 2017 Proxy Statement COMPENSATION DISCUSSION AND ANALYSIS Mitigate Undue Risk and Risk Assessment The compensation committee regularly assesses whether our compensation programs and arrangements for our employees are designed not to encourage excessive risk-taking.  We mitigate undue risk in our compensation program by instituting strong governance policies such as capping potential payments, utilizing multiple performance metrics, striking a balance between short- and long-term incentives and adopting share ownership requirements. Compensation at Risk We grant a high percentage ofat-risk compensation to our executive officers. We believe this is essential to creating a culture ofpay-for-performance. Risk AssessmentNo 280G Gross-Up Provisions The compensation committee regularly assesses whether our compensation programsno longer permits 280G gross-up provisions in the Company’s executive employment agreements and arrangementsamendments. Double-Trigger Change-in-Control Provisions Our executive officers do not receive change in control benefits under their equity awards or their employment agreements unless their employment is also terminated without cause (or by the executive for our employees encourage excessive risk-taking to ensure that our plans and awards are designed and workinggood reason) within a specified period following a change in a manner that does not encourage excessive risk taking.control. Anti-Hedging and Pledging Policy We prohibit our directors, executive officers, and all employees from hedging or pledging the Company’s securities. Independent Compensation Consultant The compensation committee retains and annually reviews the independence of its compensation consultant. 2019 Proxy Statement        35 Table of Contents COMPENSATION DISCUSSION AND ANALYSIS How We Make Compensation Decisions Our compensation committee is responsible for, among other matters: (1) reviewing key executive compensation goals, policies, plans and programs; (2) reviewing the compensation of our executive officers; (3) reviewing and approving employment agreements and other similar arrangements between the Company and our executive officers; and (4) administering our equity-based plans and other incentive compensation plans. Our Chief Executive Officer and President reviews annually with the compensation committee each NEO’s performance (other than his own) and recommends to the compensation committee appropriate base salary, annual cash incentive awards and long-term equity incentive awards (to the extent applicable with respect to a particular year) for these NEOs. Based upon the recommendations of our Chief Executive Officer and President, and after considering the objectives of our executive compensation program, as described above, as well as the factors described below under “—“Use of Benchmarking Comparison Data”Data”, the compensation committee makesmade the final recommendation to the Board for annual compensation packages of our executive officers. With respect to our Chief Executive Officer and President, the compensation committee and/or the Board reviews annuallyreviewed his annual performance and the compensation committee recommendsrecommended to the Board his base salary, annual cash incentive awards and grants of long-term equity incentive awards based on the compensation committee’s assessment of his performance, as approved by the Board. In making decisions with respect to any element of a NEO’s compensation, the compensation committee considered the total compensation that may be awarded to the executive, including salary, annual cash incentive awards and long-term incentive compensation. In addition, in reviewing and approving employment agreements for our NEOs, the compensation committee considered the other benefits to which the officer is entitled by the agreement, including compensation payable upon termination of the executive’s employment under a variety of circumstances. Our goal is to award compensation that is competitive to attract and retain highly qualified leaders and that motivates them to drive strong business performance. We believe that our compensation programs align executive and shareholder interests, while allowing compensation to vary based on each executive’s individual contributions to the Company and to the Company’s overall performance. Use of Benchmarking Comparison Data In 2015, the compensation committee selected a peer group of companies, with assistance from Willis Towers Watson, for use in making 2016 compensation decisions, with respect to the total mix and amount of compensation. This peer group consists of companies in the chemical and chemical-related industries, as well as companies in the container and packaging and paper and forest product industries. The compensation committee reviewed various market-based metrics of the peer group that it deemed appropriate, which included enterprise value, revenue, market capitalization, and EBITDA margins, to establish compensation benchmarks. 2017 Proxy Statement 25 COMPENSATION DISCUSSION AND ANALYSIS The compensation committee may annually review the companies included in our peer group and may add or eliminate companies as it determines to be appropriate. The peer group selected for making fiscal 2016 compensation decisions consisted of the following 22 companies: A. Schulman, Inc. Eastman Chemical Company PolyOne Corporation Axiall Corporation Ferro Corporation Resolute Forest Products Inc. Berry Plastics Group, Inc. Graphic Packaging Holding Company RPM International Inc. Boise Cascade Company Greif, Inc. Silgan Holdings Inc. Cabot Corporation HB Fuller Company Stepan Company Celanese Corporation Kraton Performance Polymers, Inc. Tronox Limited Chemtura Corporation Olin Corporation Domtar Corporation OMNOVA Solutions Inc. Additionally, the compensation committee reviewed various data from Willis Towers Watson databases to supplement data from the peer group. This data allowed the compensation committee to obtain a broader understanding of market compensation levels.Independent Compensation Consultant The compensation committee has retained Willis Towers Watson as its independent compensation consultant. Willis Towers Watson provides the compensation committee with advice on a broad range of executive compensation matters. The scope of their services includes, but is not limited to, the following: · Apprising the compensation committee of compensation-related trends and developments in the marketplace; · Informing the compensation committee of regulatory developments relating to executive compensation practices; · Providing the compensation committee with an assessment of the market competitiveness of the Company’s executive compensation; · Assessing the composition of the peer companies used for comparative purposes; · Assessing the executive compensation structure to confirm that no design elements encourage excessive risk taking; and · Identifying potential changes to the executive compensation program to maintain competitiveness and ensure consistency with business strategies, good governance practices and alignment with shareholder interests. Apprising the compensation committee 36        2019ProxyStatement Table of compensation-related trends and developments in the marketplace;Contents COMPENSATION DISCUSSION AND ANALYSIS Informing the compensation committee of regulatory developments relating to executive compensation practices; Providing the compensation committee with an assessment of the market competitiveness of the Company’s executive compensation; Assessing the composition of the peer companies used for comparative purposes; Assessing the executive compensation structure to confirm that no design elements encourage excessive risk taking; and Identifying potential changes to the executive compensation program to maintain competitiveness and ensure consistency with business strategies, good governance practices and alignment with shareholder interests. During fiscal 2016,2018, Willis Towers Watson attended all regularly scheduled meetings of the compensation committee. In addition to providing the compensation committee with these executive compensation consulting services in 2016,2018, for which it received aggregate fees of $200,000,$208,000, Willis Towers Watson also provided the Company with the following additional services for which it received fees totaling $290,000:$220,000: international actuarial support for the Company’s pension and postretirement benefit plans; actuarial support for one of the Company’s domestic welfare benefit plans; and compensation support to management. Before Willis Towers Watson undertook any compensation support work for the Company’s management, the compensation committee was consulted and approved the scope of work. The compensation committee actively considered the range of the additional services that Willis Towers Watson was already providing to the Company when it made the decision to retain Willis Towers Watson as its independent compensation consultant in 2016.2018. The compensation committee assessed the independence of Willis Towers Watson pursuant to applicable SEC rules and concluded that no conflict of interest exists that would prevent Willis Towers Watson from independently representing the compensation committee. 2016Use of Benchmarking Comparison Data The compensation committee selects a peer group of companies, with assistance from Willis Towers Watson, for use in making compensation decisions with respect to the total mix and amount of compensation. This peer group consists of companies in the chemical and chemical-related industries, as well as companies in the container and packaging and paper and forest product industries. The compensation committee reviewed various market-based metrics of the peer group that it deemed appropriate, which included enterprise value, revenue, market capitalization, and EBITDA margins, to establish compensation benchmarks. The compensation committee may annually review the companies included in our peer group and may add or eliminate companies as it determines to be appropriate. The peer group selected for making fiscal 2018 compensation decisions consisted of the following 22 companies: A. Schulman, Inc. Kronos Worldwide, Inc. Silgan Holdings Inc. Ashland Global Holdings Inc. Methanex Corporation Stepan Company Cabot Corporation Minerals Technologies Inc. Tronox Limited Domtar Corporation NewMarket Corporation Valvoline Inc. H.B. Fuller Company Olin Corporation Venator Materials PLC Graphic Packaging Holding Company Platform Specialty Products Corporation W. R. Grace & Co. Greif, Inc. PolyOne Corporation Kraton Corporation RPM International Inc. Additionally, the compensation committee reviewed various data from Willis Towers Watson databases to supplement data from the peer group. This data allowed the compensation committee to obtain a broader understanding of market compensation levels. 2018 Compensation Structure & Performance The principal components of our executive compensation program include both short-term and long-term compensation. Short-term compensation consists of an executive’s annual base salary and annual cash incentive award. Long-term compensation may include grants of share-based incentives as determined by the compensation committee and approved by the Board. Certain elements of compensation of our NEOs were determined through direct negotiation with the executives at the time of their hiring. 26 2017 Proxy Statement 2019 Proxy Statement        37 Table of Contents COMPENSATION DISCUSSION AND ANALYSIS Base Salary Setting appropriate levels of base pay allows us to attract and retain an executive leadership team that will continue to meet our commitments to customers, sustain profitable growth and create value for our shareholders. The base salaries for our NEOs wereare determined based on the scope of their responsibilities and our compensation committee members’ collective knowledge of competitive compensation levels, as well as competitive compensation benchmarking data from Willis TowerTowers Watson based on our peer group.group and survey data. Base salaries are reviewed annually by the compensation committee and adjusted from time to time to reflect individual responsibilities, performance and experience, as well as market compensation levels. In 2016,2018, Mr. Pappas’ base salary was raised to $1,100,000 from $1,050,000$1,200,000, effective January 1, 2016. None2018, pursuant to the terms of his employment agreement. In addition, the other NEOs receivedcompensation committee approved increases to the base salaries for the following NEOs: 1.0% increase for Mr. Niziolek, 1.1% increase for each of Messrs. Stedman and Yarkadas, and a 3.6% increase for Mr. Chaclas. The Company’s new President and Chief Executive Officer, Mr. Bozich, is entitled to an increase to his baseannual salary in 2016.of $1,000,000 for 2019. Annual Cash Incentive Plan Our annual cash incentive plan is designed to create a pay for performance culture by aligning the compensation program to the achievement of our strategic and business objectives and with shareholder interests. Our business objectives are to: (1) provide a safe working environment; (2) deliver strong recurring profits relative to our industry; (3) effectively manage our working capital; (4) demonstrate effective cost management; and (5) provide EBITDA growth that is stronger than the industry. The actual amount that will be paid in respect of an annual cash incentive awardsaward is based on a combination of the achievement of Company performance goals as well as individual performance. The performance goals and metrics are recommended by the compensation committee to the Board at the beginning of the year. At the end of the year, the amount paid to each NEO is based on the achievement of the Company performance goals and an assessment of the executive’s overall performance. For 2016,2018, the annual cash incentive plan was designed to align our executives’ compensation with the Company’s business plan and priorities for the year, and reward performance based on the following three components: • · Responsible Care®: Injuries, Spills and Process Safety Incidents (PSIs); · EBITDA: Adjusted as described below; and · Individual Goals: Performance against defined business/functional and individual goals. Individual Goals: Performance against defined business/functional and individual goals. We believebest-in-class environmental, health and safety metrics, as well as individual performance, are important measures for establishing performance objectives and measuring the performance of our NEOs. We are a Responsible Care® company and our environment, health and safety policy states that protecting people and the environment is part of everything we do and every decision we make. Each employee has a responsibility to ensure that our products and operations meet applicable government and Company standards. The 20162018 annual cash incentive plan includes three key environment, health and safety metrics that we track for our Company—Recordable Injuries as defined by OSHA, Process Safety Incidents as defined by the American Chemistry Council, and Loss of Primary Containment, which is defineddefines a containment as any physical device used to contain a chemical or plastic resin as part of our manufacturing processes. Incentive payouts with respect to these metrics are determined based on our achievement rating for Responsible Care® performance and in accordance with the threshold, target and maximum levels set forth in the table below. In 2016,2018, Company financial performance metrics were based on an Adjusted EBITDA target of $343$430 million and threshold EBITDA of $274$365 million.  The Company’s actual Adjusted EBITDA component for purposes of the 2018 annual cash incentive plan was $325 million, (in each case,which represents the Company’s year-end Adjusted EBITDA 38        2019ProxyStatement Table of Contents COMPENSATION DISCUSSION AND ANALYSIS of $573 million excluding $144 million and $107 million in earnings from our joint ventures and Feedstocks segment, of $145 million and $73 million, respectively, and including an adjustment of $30 excluding $3million to reflect the impact ofin negative raw material timing).timing. We believe that Adjusted EBITDA is a key measure of our financial performance, removing the impacts of our capital structure (such as interest expense), asset base (such as depreciation and amortization) and tax structure as well as othernon-recurring items. Therefore, for purposes of the annual cash incentive plan, we define Adjusted EBITDA, which is considered anon-GAAP measure, as net income (loss) from continuing operations before interest expense, net provision for income taxes; depreciation and amortization expense; asset impairment charges; loss on extinguishment of long-term debt,debt; gains or losses on the disposition of businesses and assets, restructuring and othernon-recurring items. Our Adjusted EBITDA performance target metric for the 20162018 annual cash incentive awards is set consistent to our 20162018 business plan that was approved by the Board, but is also adjusted to exclude earnings from the Company’s joint ventures and its Feedstocks segment and to exclude the impacts of raw material timing. See “Item 7—Management’s Discussion and Analysis of Financial Condition and Results ofOperations—Non-GAAP Performance Measures” of our Annual Report on Form10-K 10‑K for more information on our approach to calculating Adjusted EBITDA. We exclude the earnings of our Americas Styrenics segment because as a joint ventures becauseventure the Company does not have direct control of theirits day-to-day operations. WeAdditionally, we also exclude the earnings of our Feedstocks segment and the impacts of raw material timing because market volatility within this segment and timing impacts are generally outside of our executives’ control but can have a significant positive or negative impact on the Company’s financial performance. 2017 Proxy Statement 27 COMPENSATION DISCUSSION AND ANALYSIS The table below shows the weight and targets of the component metrics, along with the payout opportunity for the annual cash incentive plan.                                       Level of                   Performance     Performance Goal      Weight      Threshold      Target      Exceeds 1. Responsible Care®                           Recordable Injuries*    5  %     7      5      3 Loss of Primary Containment*    5  %     8      6      4 Process Safety Incidents*    5  %     2      1      0 Sub-total   15  %                    2. Financial Performance                         2018 EBITDA Target (Per 2018 Business Plan)   60  %   $ 365M   $ 430M   $ 500M 3. Individual Goals   25  %                    Total Opportunity at Target   100  %                    Maximum Opportunity   200  %                      Performance Goal    Weight     Threshold      Level of Performance Target      Exceeds   1. Responsible Care®            Recordable Injuries*      5 %      8        6        4   Loss of Primary Containment*      5 %      10        7        4   Process Safety Incidents*      5 %      2        1        0   Sub-total      15 %          2. Financial Performance            2016 EBITDA Target (Per 2016 Business Plan)      60 %    $ 274M      $ 343M      $ 403M   3. Individual Goals      25 %          Total Opportunity at Target      100 %          Maximum Opportunity      200 %                            *     Metrics represent incident count. * Metrics represent incident count. In 2016,2018, our achievement rating for Responsible Care® performance qualified each NEO for a 30%167% annual cash incentive award payout for the Responsible Care®component. In addition, based on our 20162018 audited financial results, our compensation committee determined that our financial performance component resulted in 82%none of the Adjusted EBITDA portion of the bonus becoming payable. Actual results for Responsible Care® and Adjusted EBITDA financial performance are set forth below:     % of     Actual Result     Payout % of Target     Weighted Payout          Metric Weight                        Responsible Care®                              Recordable Injuries*   5  %       5     100  %   5  % Loss of Primary Containment*   5  %       2     200  %   10  % Process Safety Incidents*   5  %       0     200  %   10  % Responsible Care Total   15  %             167  %   25  % Financial Performance (Adjusted EBITDA)   60  %     $ 325M     0  %   0  %        % of Metric Weight            Level of Performance          Actual      Threshold      Target      Exceeds   Responsible Care®               Recordable Injuries*      10 %      2        8        6        4   Loss of Primary Containment*      10 %      4        10        7        4   Process Safety Incidents*      10 %  ��   0        2        1        0   Responsible Care Total      30 %             Financial Performance (Adjusted EBITDA)      82 %    $ 365M      $ 274M      $ 343M      $ 403M   *     Metrics represent incident count. * Metrics represent incident count. 2019 Proxy Statement        39 Table of Contents COMPENSATION DISCUSSION AND ANALYSIS In addition, each NEO had personal performance goals that included, depending on the individual: corporate or business EBITDA; asset, product optimization and customer profitability; organizational effectiveness; people leadership,people; and cost management. The results achieved against each of these goals were assessed by the compensation committee and ratings were assigned. During 2016,2018, the target bonus under this plan for each NEO was based on a percentage of base salary ranging from 150%, in the case of Mr. Pappas, to 75%, in the case of Mr. Pugh, 70% in the case of Mr. Niziolek, and 60%65% in the case of Messrs. Stedman, Yarkadas, and Yarkadas.Chaclas. The table below shows the 20162018 target annual incentive award for each NEO and the actual award payable, based on our performance and the individual’s performance.                       Target             NEO      Percentage      Target Amount      Actual Amount Christopher D. Pappas   150  %   $ 1,800,000    $ 843,750  Barry J. Niziolek   70  %   $ 371,000    $ 178,544  Timothy M. Stedman(1)   65  %   $ 319,600    $ 155,805  Hayati Yarkadas(1)   65  %   $ 319,600    $ 151,011  Angelo N. Chaclas   65  %   $ 282,750    $ 142,553    NEO    Target Percentage     Target Amount      Actual Amount   Christopher D. Pappas      150 %    $ 1,650,000      $ 2,467,960   Martin Pugh(1)      75 %    $ 454,500      $ 653,344   Barry J. Niziolek(2)      70 %    $ 350,000      $ 273,000   Timothy M. Stedman(1)      60 %    $ 272,700      $ 396,779   Hayati Yarkadas(1)      60 %    $ 272,700      $ 402,574   (1) Messrs. Pugh, Stedman,Stedman’s and Yarkadas’ compensation is payable in CHF and was converted using the foreign exchange rate of US$1.011.02436 to CHF1.00. This rate was determined by averaging the monthly exchange rates in effect during 2016.2018. (2) Mr. Niziolek’s actual amount waspro-rated to reflect his June 2016 hire date. 28 2017 Proxy Statement COMPENSATION DISCUSSION AND ANALYSIS The table below shows the contribution of each performance metric under our annual cash incentive plan to the actual bonus award earned by our NEOs. All values in this table are shown as a percentage of target.                         Responsible   EBITDA   Individual   Actual Award as   NEO      Care (15%)      (60%)      Goals (25%)      a % of Target   Christopher D. Pappas   167  %   0  %   88  %   47  % Barry J. Niziolek   167  %   0  %   93  %   48  % Timothy M. Stedman   167  %   0  %   95  %   49  % Hayati Yarkadas   167  %   0  %   89  %   47  % Angelo N. Chaclas   167  %   0  %   102  %   50  %   NEO    Responsible Care (15%)     EBITDA (60%)     Individual Goals (25%)     Actual Award as a % of Target   Christopher D. Pappas      200 %      136 %      150 %      149.5 %  Martin Pugh      200 %      136 %      127 %      143.8 %  Barry J. Niziolek      200 %      136 %      128 %      144.0 %  Timothy M. Stedman      200 %      136 %      134 %      145.5 %  Hayati Yarkadas      200 %      136 %      143 %      147.6 %  Long-Term Equity Incentive Compensation In February 2016,2018, our Board approved equity award grants to certain key employees, including for NEOs Pappas, Pugh, Stedman and Yarkadas. Mr. Niziolek’s equity award grant was approved in June 2016 due to timing of his start of service with the Company.NEOs. Each of our NEOs received a grant of restricted stock units and options to purchase our ordinary shares (30%), RSUs (30%), and PSUs (40%), based on a target percentage of their base salary, as shown in the table below. These awards are subject to time-based vesting conditions, with restricted share unit awardsRSUs vesting in full on the third anniversary of the date of grant, PSUs vesting in full on the third anniversary of the date of grant, subject to the Company’s relative TSR performance, and options vesting in three equal annual installments beginning on the first anniversary of the date of grant, ingrant. In each case, vesting is generally subject to athe NEO’s continuous employment with us on the applicable vesting date. OurIn 2017, the Board chose to grant long-term incentives infor the form of stock options and restricted stock units to align the interests of our executives with those of our shareholders, encourage a longer-term view on thefirst time included PSUs as part of the executive’s target equity compensation to put a greater focus on at-risk, long-term incentive-based compensation. We believe the addition of PSUs, along with providing a higher concentration of equity compensation in PSUs as compared to the RSU and stock option components, provides greater alignment between our executives, and to provide a retention tool, primarily in the form of restricted stock units since they will not vest until the third anniversary of the date of grant. Fifty percent of the grant date value of each NEO’s 2016 award was in the form of stock optionsexecutive compensation program and the other fifty percent increation of shareholder value through the formCompany’s long-term strategic initiatives. In addition, our Board considers the 40        2019ProxyStatement Table of restricted stock units. Our board considers the Contents COMPENSATION DISCUSSION AND ANALYSIS stock options to be performance-based because a stock option will only have value to the extent that our stock price increases after the date the stock option is granted. For 2017, the Board changed its long-term incentive compensation components to put a greater focus onat-risk, long-term incentive-based compensation by including performance award stock units (“PSUs”) as 40% of the executive’s target equity compensation. The PSUs will vest on the third anniversary of the grant date, subject to the Company’s relative TSR performance. We believe the addition of PSUs, along with providing a higher concentration of equity compensation in PSUs as compared to our restricted stock unit and stock option components, will provide greater alignment between our executive compensation program and the creation of shareholder value through the Company’s long-term strategic initiatives.                 LTI     LTI Name      Target %      Target Amount Christopher D. Pappas   480  %   $ 5,760,000  Barry J. Niziolek   175  %   $ 927,500  Timothy M. Stedman(1)   135  %   $ 663,785  Hayati Yarkadas(1)   135  %   $ 663,785  Angelo N. Chaclas   140  %   $ 609,000    Name      Target Percentage        Target Amount   Christopher D. Pappas        450 %       $ 4,950,000   Martin Pugh(1)        175 %       $ 1,069,006   Barry J. Niziolek        155 %       $ 775,000   Timothy M. Stedman(1)        100 %       $ 458,146   Hayati Yarkadas(1)        100 %       $ 458,146   (1) Messrs. Pugh, Stedman,Stedman’s and Yarkadas’ compensation is payable in CHF and the above target amount was converted using the foreign exchange rate of US$1.011.02436 to CHF1.00. This rate was determined by averaging the monthly exchange rates in effect during 2016.2018. PSUs granted under the 2014 Omnibus Incentive Plan will vest on the third anniversary of the grant date, subject to the Company’s relative TSR performance, assuming the reinvestment of dividends, against the performance of 50 other chemical companies with shares traded on a major U.S. stock exchange and that have a market capitalization exceeding $500 million at the time the award is granted.  The peer group for the 2018 grants is as follows: AdvanSix Inc H.B. Fuller Company Quaker Chemical Corporation Air Products and Chemicals, Inc. Huntsman Corporation Rayonier Advanced Materials Inc. Albemarle Corporation Ingevity Corporation RPM International Inc. Ashland Global Holdings Inc. Innophos Holdings, Inc. Sensient Technologies Axalta Coating Systems Ltd. Innospec Inc. Stepan Company Balchem Coproration International Flavors & Fragrances Inc. The Chemours Company Cabot Corporation Koppers Holdings Inc. The Moasic Company Celanese Corporation Kraton Corporation The Scotts Miracle-Gro Company CF Industries Holdings, Inc. Kronos Worldwide, Inc. The Sherwin-Williams Company Chase Corporation LyondellBasell Industries N.V. Tredegar Corporation Ciner Resources LP Minerals Technologies Inc. Tronox Limited Eastman Chemical Company NewMarket Corporation Valhi, Inc. Ecolab Inc. Olin Corporation Valvoline Inc. Element Solutions Inc. Platform Specialty Products Corporation W. R. Grace & Co. Ferro Corporation PolyOne Corporation Westlake Chemical Corporation FMC Corporation PPG Industries, Inc. Westlake Chemical Partners LP GCP Applied Technologies Inc. Praxair, Inc. The amount of PSUs that will vest for the 2018 awards will be as follows:                               TSE Performance   Payout % Metric      Threshold      Target      Maximum      Threshold      Target      Maximum 2018 – 2020 TSE TSR (relative to Performance Peer Group)   25th Percentile   50th Percentile   75th Percentile   50%   100%   200% *Vesting is interpolated between the 25th and 50th and between the 50th and 75th percentiles. Regardless of the targets above, vesting is capped at 100% of target if the Company’s TSR is negative for the performance period. Additionally, the total value of the awards delivered at vesting is capped at three times the target shares multiplied by the grant date share price. Because we assume reinvestment of dividends, dividend equivalents accrue during the performance period. However, dividend equivalents will be paid only if and to the extent the PSUs vest, since we do not believe the executives should receive the benefit of such dividend earnings if the performance criteria associated with the PSU award is not otherwise met.  Based off of TSR performance as of December 31, 2018, the Company’s executives would not meet the performance threshold to receive any payout under their outstanding PSU awards. 2019 Proxy Statement        41 Table of Contents COMPENSATION DISCUSSION AND ANALYSIS On September 14, 2018, Messrs. Stedman and Yarkadas also each received an equity retention award with a grant date fair value of $1.3 million consisting of 50% PSUs and 50% RSUs.  These awards vest on the same terms as the Company’s other 2018 PSU and RSU awards and utilize the same peer group selection criteria used for the 2018 annual equity awards. The Company views off-cycle equity awards as an exceptional practice and does not employ them without a distinct and necessary purpose, such as to attract or retain key executives. As the Company engaged in regular succession planning discussions, it believed securing the continued commitment of its key business presidents would be an important component to these plans and the Company’s future. Ensuring management and leadership stability through key successions and retirements was a  key concern for the Company in order to ensure these transitions did not distract the Company from its long-term strategic initiatives and business plans.  Since 2018, the Company’s former Senior Vice President of Human Resources and Mr. Pappas retired, along with Mr. Niziolek recently announcing his intention to retire by mid-year 2019. Despite the retention nature of these awards, the compensation committee believed that a substantial portion of these awards should be performance-based in order to further align the executive’s compensation incentives with the creation of shareholder value through the Company’s long-term strategic initiatives.  The compensation committee considers Messrs. Stedman and Yarkadas (and other executives who would likewise receive an off-cycle award) as ineligible for consideration for any further off-cycle equity award until the current awards have vested. Other Compensation and Tax Matters Retirement Benefits Our qualified U.S. savings plan (the “401(k) plan”) provides for (1) annual discretionary Company contributions and (2) employer matching contributions to be credited to participants’ accounts. The U.S.-based NEOs participate in this plan on the same basis as our other employees. We also maintain anon-qualified U.S. savings and deferral plan in which each of our U.S.-based NEOs participates.participate. This plan allows participants to defer a portion of their compensation on apre-tax basis, with matching contributions from the Company that are payable at a future date based on the terms of the plan. Additionally, the plan provides for discretionary Company contributions in connection with earnings that are in excess of the limitations set forth in the 401(k) Plan. 2017 Proxy Statement 29 COMPENSATION DISCUSSION AND ANALYSIS Our NEOs do not participate or have account balances in any qualified ornon-qualified defined benefit pension plans sponsored by the Company, with the exception of Messrs. Pugh, Stedman and Yarkadas who participate in our Switzerland-based defined contribution retirement plan. Additionally, under the terms of his employment agreement, Mr. Pugh received aone-time retirement allowance of $202,138, in connection with his retirement. Pursuant to the terms of Mr. Pappas’sPappas’ employment agreement, he is entitled to a retirement benefit payable in the form of a cash lump sum upon his retirement or other termination of employment in an amount determined in accordance with a formula contained in his employment agreement as described in more detail under “Executive Compensation—Pension and Other Postretirement Benefits—Supplemental Employee Retirement Benefit” below. Neither Mr. Bozich nor our other NEOs participate in any supplemental employee retirement plan, or have such a plan provided by their agreement. Severance Benefits Our NEOs are eligible for severance benefits under their employment agreements upon certain terminations of employment. The agreements provide the NEOs, except Mr. Pappas, with severance benefits in an amount equal to 1.5 times the sum of the executive’s annual base salary and target bonus. Mr. Pappas is eligible fornot entitled to any severance benefits in an amount equal to 2.0 times the sumconnection with his retirement. 42        2019ProxyStatement Table of his annual base salary and target bonus.Contents Change-in-Control Severance BenefitsCOMPENSATION DISCUSSION AND ANALYSIS We providechange-in-control severance benefits to certain executives, including our current NEOs. Thesechange-in-control severance benefits are intendedconsidered “double triggers” and designed to minimize the distraction and uncertainty that could affect key management in the event we become involved in a transaction that could result in a change in control of the Company and to enable the executives to impartially evaluate such a transaction. Under the terms of these agreements, each NEO is entitled to a lump sum payment equal to the severance benefits set forth above (rather than payment of severance benefits in installments) if the NEO experiences a termination of employment other than for cause or in the event the NEO resigns for good"good reason," as defined in the agreements, within two years following achange-in-control of the Company. Mr. Pappas is also entitled to aso-called 280Ggross-up with respect to certain payments that may be made to him in connection with a change in control, a benefit that was negotiated at the time Mr. Pappas was hired by us. The compensation committee does not intend to include apermit 280Ggross-up provisions in any newits executive employment agreements or amendments to existing agreements with any other executives.amendments. Other Compensation Other Compensation Each NEO is eligible to participate in our generally-applicable benefit plans, such as savings, medical, dental, group life, disability and accidental death and dismemberment insurance, in accordance with country practices. Additionally, the Company may offer certain perquisites to certain executives when appropriate or necessary to recruit or retain talented and qualified individuals. As a Company that operates worldwide, we often offer certain types of perquisites to our executives, such as moving or commuting expenses, in order to compensate individuals who relocate. See the footnotes to the “Summary Compensation Table” and the “Narrative“Narrative Disclosure to Summary Compensation Table and Grants of Plan Based Awards Table; Other Narrative Disclosure”Disclosure” below for more details regarding the other compensation paid to our NEOs. Tax and Accounting Considerations Prior to January 1, 2018, Section 162(m) of the Code imposesimposed a limit of $1,000,000 on the amount that a publicly-traded company may deduct for federal income tax purposes in any taxable year for compensation paid to our CEO and the three other highest-paid NEOs, other than our CFO, who are employed as of the end of the year. To the extent that compensation iswas “performance-based” within the meaning of Section 162(m) or to the extent that compensation meeting certain requirements is paid during a limited period of time following our IPO, the Section’s limitations willdid not apply. To qualify as performance based,performance-based, compensation must, among other things, be paid pursuant to a shareholder approved plan upon the attainment of objective performance criteria. On December 22, 2017, the Tax Cuts and Jobs Act amended Section 162(m) to eliminate the exemption for performance-based compensation under Section 162(m). These amendments made all compensation paid to a covered employee in excess of $1 million nondeductible, including post-termination and post-death payments, severance, deferred compensation and payments from nonqualified plans. The Tax Cuts and Jobs Act also provided a transition rule that does not apply these amendments to Section 162(m) to written binding contracts in effect on November 2, 2017 and not subsequently amended or modified. Our compensation committee believes that the tax deductibility of compensation is an important factor, but not the sole factor, in setting executive compensation policies and in rewarding superior executive performance. However, the compensation committee reserves the rightThe Company has not historically needed to approve the payment of compensation to our executive officers that does not qualify as “performance-based” within the meaning ofrely on Section 162(m) and therefore, maydue to the large amount of its executives’ compensation services performed outside the United States. Therefore, its compensation programs have not be deductible for federal income tax purposes.been materially impacted by the changes to Section 162(m). In determining variable compensation program designs, our compensation committee also considers other tax and accounting implications of particular forms of compensation, such as the implications of Section 409A of the Code governing deferred compensation arrangements and favorable accounting treatment afforded certain equity based plans that are settled in shares. 30 2017 Proxy Statement 2019 Proxy Statement        43 Table of Contents COMPENSATION DISCUSSION AND ANALYSIS Timing of Awards We regularly award annual equity grants to our executive officers in February of each year, so as to provide apre-set schedule for our equity grants that won’t be impacted by events external or internal to the Company. New hires may, depending on the timing of their hire, be eligible for a grant at the next board meeting following his or her hire.   2017 Proxy Statement 31 EXECUTIVE COMPENSATION   44        2019ProxyStatement Table of Contents EXECUTIVE COMPENSATION Executive Compensation Summary Compensation Table The following table sets forth information regarding the compensation paid to or earned by our NEOs for the years ended December 31, 2016, 2015,2018, 2017, and 2014,2016, as applicable. For additional information, please read the footnotes and narrative disclosures that follow the table.                                                                                                                  Changes in                                                         Pension                                                   Value                                                   and Non-                                                   qualified                                             Non-Equity   Deferred                                 Stock   Option   Incentive Plan   Compensation   All Other       Name and       Salary   Bonus   Awards   Awards   Compensation   Earnings   Compensation     Principal Position   Year   ($)(1)   ($)(2)   ($)(3)   ($)(4)   ($)(5)   ($)(6)(7)   ($)(8)   Total ($) Christopher D. Pappas   2018   $ 1,200,000   $ —   $ 4,239,343   $ 1,725,105   $ 843,750   $ 492,829   $ 168,206   $ 8,669,233 President and Chief   2017   $ 1,150,000   $  —   $ 3,913,374   $ 1,621,518   $ 2,448,324   $ 762,155   $ 196,378   $ 10,091,749 Executive Officer   2016   $ 1,100,000   $  —   $ 2,475,010   $ 2,409,702   $ 2,467,960   $ 315,140   $ 180,961   $ 8,948,773 Barry J. Niziolek   2018   $ 530,000   $ —   $ 682,665   $ 277,787   $ 178,544   $ —   $ 69,081   $ 1,738,077 EVP & Chief Financial Officer   2017   $ 525,000   $  —   $ 589,216   $ 244,127   $ 512,412   $  —   $ 66,272   $ 1,937,027     2016   $ 259,615   $  —   $ 387,524   $ 387,964   $ 273,000   $  —   $ 20,135   $ 1,328,238 Timothy M. Stedman(9)    2018   $ 491,693   $ 261,212   $ 1,876,672   $ 208,234   $ 155,805   $ 341,112   $ 110,475   $ 3,445,203 SVP and Business President   2017   $ 483,408   $ 463,054   $ 395,595   $ 163,885   $ 415,291   $ 145,531   $ 122,911   $ 2,189,675     2016   $ 454,500   $ 459,550   $ 229,083   $ 223,033   $ 396,779   $ 163,198   $ 138,796   $ 2,064,939 Hayati Yarkadas(9)   2018   $ 491,693   $ 348,282   $ 1,876,672   $ 208,234   $ 151,011   $ 353,404   $ 120,095   $ 3,549,391 SVP and Business President   2017   $ 483,408   $ 284,956   $ 395,595   $ 163,885   $ 408,040   $ 144,513   $ 141,363   $ 2,021,760     2016   $ 454,500   $ 202,000   $ 229,083   $ 223,033   $ 402,574   $ 162,184   $ 174,301   $ 1,847,675 Angelo N. Chaclas   2018   $ 435,000   $ —   $ 448,224   $ 182,397   $ 142,553   $ —   $ 58,079   $ 1,266,253 SVP, CLO, CCO and   2017   $ 420,000   $  —   $ 410,597   $ 170,110   $ 515,960   $  —   $ 57,939   $ 1,574,606 Corporate Secretary   2016   $ 390,000   $  —   $ 243,755   $ 237,328   $ 476,587   $  —   $ 43,043   $ 1,390,712   Name and Principal Position   Year     Salary ($)(1)     Bonus ($)(2)     Stock Awards ($)(3)     Option Awards ($)(4)     Non-Equity Incentive Plan Compensation ($)(5)     Changes in Pension Value and Non- qualified Deferred Compensation Earnings ($)(6)(7)     All Other Compensation ($)(8)     Total ($)   Christopher D. Pappas President and Chief Executive Officer     2016     $ 1,100,000     $ —     $ 2,475,010     $ 2,409,702     $ 2,467,960     $ 315,140     $ 180,961     $ 8,948,773       2015     $ 1,050,000     $ —     $ 2,100,000     $ 2,100,000     $ 2,693,250     $ 2,048,653     $ 164,000     $ 10,155,903       2014     $ 1,000,001     $ 500,000     $ —     $ —     $ 1,218,725     $ 2,865,711     $ 165,104     $ 5,749,541   Martin Pugh(9) EVP & Chief Operating Officer     2016     $ 606,000     $ —     $ 534,518     $ 520,402     $ 653,344     $ 415,550     $ —     $ 2,729,814       2015     $ 622,200     $ —     $ 467,560     $ 467,560     $ 662,249     $ 184,440     $ —     $ 2,404,009       2014     $ 603,900     $ 549,000     $ —     $ —     $ 271,030     $ 424,591     $ —     $ 1,848,521   Barry J. Niziolek EVP & Chief Financial Officer     2016     $ 259,615     $ —     $ 387,524     $ 387,964     $ 273,000     $ —     $ 20,135     $ 1,328,238   Timothy M. Stedman(9) SVP and Business President, Basic Plastics and Feedstocks     2016     $ 454,500     $ 459,550     $ 229,083     $ 223,033     $ 396,779     $ 163,198     $ 138,796     $ 2,064,939   Hayati Yarkadas(9) SVP and Business President, Performance Materials     2016     $ 454,500     $ 202,000     $ 229,083     $ 223,033     $ 402,574     $ 162,184     $ 174,301     $ 1,847,675   (1) (1) The amount shown for Mr. Niziolek for 2016 represents the portion of base salary he received during the period between his hire date of June 13 and December 31, 2016. Prior to Mr. Niziolek’s hiring Mr. Pappas served as the Company’s interim Chief Financial Officer.2016 (2) (2) The amount in this column for Mr. Pappas reflects his special retention award paid in 2014. The amount in this column for Mr. Pugh reflects a retention bonus as part of his employment agreement, of which CHF 500,000 was paid in 2014. The amountamounts in this column for Messrs. Stedman and Yarkadas reflect signing bonuses of CHF 455,000 and CHF 200,000, respectively, paid in 2016. The signing bonuses for Messrs. Stedman and Yarkadas were contingent on the executive’s continued employment through thehis first, anniversary of their employmentsecond, and third anniversaries, respectively, with the Company and were compensation for equity grants from previous employers that were forfeited upon their employment with the Company. Please see “—Narrative Disclosure to Summary Compensation Table and Grants of Plan Based Awards Table; Other Narrative Disclosure”Disclosure” for a description of the staggered signing bonuses due to Messrs. Stedman and Yarkadas under their respective employment agreements. (3) (3) The amount in this column reflects the fair value of restricted stock unitRSU and PSU awards granted in the periods presented, calculated in accordance with ASC 718. The assumptions used for determining fair value are described in Note 17 to our consolidated financial statements filed with our Annual Report on Form10-K. 10‑K. There were no grants of restricted stock unitRSU awards and PSU awards under the 2014 Omnibus Incentive Plan prior to 2015.2015 and 2017, respectively. For purposes of this table it is presumed that the PSU awards will be settled at target levels.   (4) (4) The amount in this column reflects the fair value of option awards granted in the periods presented, computed using the Black-Scholes pricing model, whose inputs and assumptions are as of the grant dates and described in Note 17 to our consolidated financial statements filed with our Annual Report on Form10-K. There were no grants of option awards under the 2014 Omnibus Incentive Plan prior to 2015. 10‑K. (5) (5) This amount includes each NEO’s earned cash incentive payout as discussed in “Compensation“Compensation Discussion and Analysis—Compensation Elements—Annual Cash Incentive Plan” above. For Mr. Chaclas, this amount includes incentive payouts under the Company's 2013 and 2014 Long-Term Incentive Plans. Please see “— Narrative Disclosure to Summary Compensation Table and Grants of Plan” above. Based Awards Table; Other Narrative Disclosure” for a description of these plans. (6) (6) The amount in this column reflects the aggregate change in the actuarial present value of the applicable named executive officer’s accumulated benefit under our defined benefit pension plan and arrangements in respect of each year in the table, as follows: fortable. Messrs. Pappas, Pugh, StedmanNiziolek and Yarkadas for the year December 31, 2016 $315,140, $415,550, $163,198, and $162,184, respectively; for Messrs. Pappas and Pugh for the year December 31, 2015 $2,048,653 and $184,440, respectively; for Messrs. Pappas and Pugh for the year ended December 31, 2014 $2,865,711 and $424,591, respectively. Mr. Niziolek didChaclas do not participate in pension and other postretirement benefit arrangements. Please see “—Pension and Other Postretirement Benefits” for a description of these arrangements. (7) (7) No amount is reported with respect to earnings onnon-qualified deferred compensation plans because above market rates are not provided under such plans. See “—U.S.Non-Qualified Deferred Compensation Table” below for information with respect to the NEOs’ deferred compensation amounts for 2016.2018. 2019 Proxy Statement        45 Table of Contents EXECUTIVE COMPENSATION (8) 32 2017 Proxy Statement EXECUTIVE COMPENSATION (8) Included in “All Other Compensation” for fiscal year 20162018 were the following items:                                                               Non-qualified                                               401k   deferred   Dependent   Relocation   Living   Tax             NEO   Plan(i)   comp plan(ii)   Education(iii)   Services(iv)   Stipend(v)   Gross-up(vi)   Other(vii)   Total Christopher D. Pappas   $  24,750   $  143,075   $  —   $ —   $  —   $  —   $  381   $ 168,206 Barry J. Niziolek   $  24,750   $  43,950   $  —   $ —   $  —   $  —   $  381   $ 69,081 Timothy M. Stedman   $  —   $  —   $  —   $ 21,974   $  55,315   $  22,440   $  10,747   $ 110,475 Hayati Yarkadas   $  —   $  —   $ 86,030   $ —   $  —   $ 25,206   $  8,859   $ 120,095 Angelo N. Chaclas   $ 24,750   $  32,948   $  —   $ —    $  —   $  —   $  381   $ 58,079   NEO   401k Plan(i)     Non-qualified deferred comp plan(ii)     Dependent Education(iii)     Executive Education(iv)     Living Stipend(v)     Tax Gross-up(vi)     Other(vii)     Total   Christopher D. Pappas   $ 21,327     $ 158,050       —       —       —       —     $ 1,584     $ 180,961   Barry J. Niziolek   $ 19,404       —       —       —       —       —     $ 731     $ 20,135   Timothy M. Stedman     —       —       —       —     $ 72,720     $ 51,036     $ 15,040     $ 138,796   Hayati Yarkadas     —       —     $ 93,200     $ 15,755       —     $ 58,175     $ 7,171     $ 174,301   (i) Represents Company matching and discretionary contributions to the 401(k) Plan for Messrs. Pappas, Niziolek, and Niziolek.Chaclas. (ii) Represents Company matching and discretionary contributions to ournon-qualified deferred compensation plan (such amounts are also included in the “U.S.Non-Qualified Deferred Compensation Table” below). (iii) Represents education expenses provided to Mr. Yarkadas’ dependents, which primarily consists of the payment of $89,765 of tuition for his two minor children provided for in his employment agreement, with the remainder being local language lessons for his spouse.dependents. Please see “—Narrative Disclosure to Summary Compensation Table and Grants of Plan Based Awards Table; Other Narrative Disclosure” for a description of Mr. Yarkadas’ employment agreement. (iv) Represents reimbursements for executive and local language education for Mr. Yarkadas. (v) Represents Mr. Stedman’s temporary CHF 6,000 monthly incidental living expense allowance.allowance through September 2018. Please see “—Narrative Disclosure to Summary Compensation Table and Grants of Plan Based Awards Table; Other Narrative Disclosure” for a description of Mr. Stedman’s employment agreement. (vi) (v) Mr. Stedman received certain relocation services under his employment agreement.  Please see “— Narrative Disclosure to Summary Compensation Table and Grants of Plan Based Awards Table; Other Narrative Disclosure” for a description of Mr. Stedman’s employment agreement. (vi) Mr. Stedman received agross-up for tax purposes on the living stipend paid to him. Mr. Yarkadas received agross-up for tax purposes on the tuition paid on behalf of his minor children. Please see “—Narrative Disclosure to Summary Compensation Table and Grants of Plan Based Awards Table; Other Narrative Disclosure” for a description of Messrs. Stedman’s and Yarkadas’ employment agreements. (vii) Represents the aggregate of all other compensation items paid to the NEOs for personal benefits, which individually do not exceed $10,000. For Messrs. Pappas, Niziolek, and NiziolekChaclas, these amounts represent group life insurance premiums. For Messrs. Stedman andMr. Yarkadas, the amount in this column includes $7,915represents a child education allowance provided by the Swiss government and $7,171, respectively,tuition for tax planning services.language classes. For Mr. Stedman, the amounts in this column also includes $7,125 inrepresent tax planning services and personal commuting expenses paid to him under histhis employment agreement. Please see “—Narrative Disclosure to Summary Compensation Table and Grants of Plan Based Awards Table; Other Narrative Disclosure” for a description of Mr. Stedman’s employment agreement. (9) (9) Compensation for Messrs. Pugh, Stedman and Yarkadas was paid or is payable in CHF. The amount of compensation earned or received during 2016, 2015,2018, 2017 and 20142016 was converted using the foreign exchange rate of US$1.02436 to CHF1.00, US$ 1.0177 to CHF 1.00, and US$1.01 to CHF1.00, US$1.037 to CHF1.00, and US$1.098 to CHF1.00, respectively.respectively. These rates have been determined by averaging the monthly exchange rates in effect for each calendar year. 46        2019ProxyStatement Table of Contents EXECUTIVE COMPENSATION Grant of Plan-Based Awards Table The following table shows all plan-based awards granted to the NEOs during 2016.2018. All equity awards were granted under our 2014 Omnibus Incentive Plan (OIP) as a target percentage of each NEOs base salary with the target value of the equity award comprised of stock options (30%), RSUs (30%), and PSUs (40%). See “Compensation Discussion and Analysis—Compensation Elements—Long-Term Equity Incentive Compensation” for more information regarding the 2018 equity awards.  All NEOs earned cash incentive awards for 20162018 performance under the Company’s annual cash incentive plan (ACIP).                                                 Estimated Future Payouts                               Under Non-Equity                               Plan  Awards(1)                                           All other               Grant                     stock   All other           Date                     awards:   option   Exercise   Closing   Fair Value                     Number   awards:   or Base   Stock   of Stock                     of   Number of   Price of   Price on   and                     shares of   securities   Option   Grant   Option     Grant   Threshold   Target   Maximum   stock or   underlying   Awards   Date   Awards Name   Date   ($)   ($)   ($)   units (#)   options (#)   ($/Shy)   ($/Sh)   ($) Christopher D. Pappas                                                                        OIP—Options   2/22/2018    —    —   -    —   77,385      81.20    —   $ 1,725,105 OIP—RSUs   2/22/2018    —    —   -   21,281    —    —   81.20   $ 1,728,017 OIP—PSUs   2/22/2018    —    —   -   28,374    —    —   81.20   $ 2,511,326 ACIP   1/1/2018    —   1,800,000   3,600,000    —    —    —    —      — Barry J. Niziolek                                                OIP—Options   2/22/2018    —    —    —    —   12,461   81.20    —   $ 277,787 OIP—RSUs   2/22/2018    —    —    —   3,427    —    —   81.20   $ 278,272 OIP—PSUs   2/22/2018    —    —    —   4,569    —    —   81.20   $ 404,393 ACIP   1/1/2018    —   371,000   742,000    —    —    —    —     0 Timothy M. Stedman                                                OIP—Options   2/22/2018    —    —    —    —   9,341   81.20    —   $ 208,234 OIP—RSUs   2/22/2018    —    —    —   2,569    —    —   81.20   $ 208,603 OIP—PSUs   2/22/2018    —    —    —   3,425    —    —   81.20   $ 303,140 OIP—RSUs   9/14/2018    —    —    —   8,672    —    —   74.95   $ 649,966 OIP—PSUs   9/14/2018    —    —    —   8,672    —    —   74.95   $ 714,963 ACIP         —    319,600   639,201    —    —    —    —      — Hayati Yarkadas                                                OIP—Options   2/22/2018    —    —    —    —   9,341   81.20    —   $ 208,234 OIP—RSUs   2/22/2018    —    —    —   2,569    —    —   81.20   $ 208,603 OIP—PSUs   2/22/2018    —    —    —   3,425    —    —   81.20   $ 303,140 OIP—RSUs   9/14/2018    —    —    —   8,672    —    —   74.95   $ 649,966 OIP—PSUs   9/14/2018    —    —    —   8,672    —    —   74.95   $ 714,963 ACIP   1/1/2018    —   319,600   639,201   —    —    —   —     — Angelo N. Chaclas                                          OIP—Options   2/22/2018    —   —   —   —   8,182   81.20   —-   $ 182,397 OIP—RSUs   2/22/2018    —   —   —   2,250    —    —   81.20   $ 182,700 OIP—PSUs   2/22/2018    —   —   —   3,000    —    —   81.20   $ 265,524 ACIP   1/1/2018    —   282,750   565,500    —    —    —   —-     —             Estimated Future Payouts Under Non-Equity Plan Awards(1)                                 Name   Grant Date     Threshold ($)     Target ($)     Maximum ($)     All other stock awards: Number of shares of stock or units (#)     All other option awards: Number of securities underlying options (#)     Exercise or Base Price of Option Awards ($/Sh)     Closing Stock Price on Grant Date ($/Sh)     Grant Date Fair Value of Stock and Option Awards ($)(2)   Christopher D. Pappas                   OIP—Options     2/22/2016       —       —       —       —       243,419       26.97       —     $ 2,409,702   OIP—RSUs     2/22/2016       —       —       —       91,769       —       —       26.97     $ 2,475,010   ACIP     2/18/2016       —       1,650,000       3,300,000       —       —       —       —       —   Martin Pugh                   OIP—Options     2/22/2016       —       —       —       —       52,569       26.97       —     $ 520,402   OIP—RSUs     2/22/2016       —       —       —       19,819       —       —       26.97     $ 534,518   ACIP     2/18/2016       —       454,500       909,000       —       —       —       —       —   (1) 2017 Proxy Statement 33 EXECUTIVE COMPENSATION           Estimated Future Payouts Under Non-Equity Plan  Awards(1)                                 Name   Grant Date     Threshold ($)     Target ($)     Maximum ($)     All other stock awards: Number of shares of stock or units (#)     All other option awards: Number of securities underlying options (#)     Exercise or Base Price of Option Awards ($/Sh)     Closing Stock Price on Grant Date ($/Sh)     Grant Date Fair Value of Stock and Option Awards ($)(2)   Barry J. Niziolek                   OIP—Options     6/22/2016       —       —       —       —       27,404       47.45       —     $ 387,964   OIP—RSUs     6/22/2016       —       —       —       8,167       —       —       47.45     $ 387,524   ACIP     6/21/2016       —       350,000       700,000       —       —       —       —       —   Timothy M. Stedman                   OIP—Options     2/22/2016       —       —       —       —       22,530       26.97       —     $ 223,033   OIP—RSUs     2/22/2016       —       —       —       8,494       —       —       26.97     $ 229,083   ACIP     2/18/2016       —       272,700       545,400       —       —       —       —       —   Hayati Yarkadas                   OIP—Options     2/22/2016       —       —       —       —       22,530       26.97       —     $ 223,033   OIP—RSUs     2/22/2016       —       —       —       8,494       —       —       26.97     $ 229,083   ACIP     2/18/2016       —       272,700       545,400       —       —       —       —       —   (1) Represents awards provided under our annual cash incentive plan discussed above under  “See “Compensation Discussion and Analysis—Compensation Elements—Annual Cash Incentive Plan”. The maximum amount represents two times the target amount. The actual amounts earned by the NEOs with respect to 20162018 are included in the“Non-Equity “Non-Equity Incentive Plan Compensation” column of the Summary Compensation Table above.   (2) Equity awards under the 2014 Omnibus Incentive Plan were granted based on a target percentage of each NEOs base salary with the target value of the equity award generally being split evenly between option awards and RSUs. See “Compensation Discussion and Analysis—Compensation Elements—Long-Term Equity Incentive Compensation” for more information regarding the 2016 equity awards. Narrative Disclosure to Summary Compensation Table and Grants of Plan-Based Awards Table; Other Narrative Disclosure We have entered into an executive employment agreement with Mr. Pappas, with his employment commencing on June 17, 2010 and having an initial term of three years. On April 11, 2013, the agreement with Mr. Pappas was amended and restated with retroactive effect as of January 2, 2013, and was extended until June 30, 2017. On March 30, 2016, Mr. Pappas’ agreement was amended again and was extended to December 31, 2018 and is subject to extension by mutual2018. On December 21, 2017, the agreement betweenwith Mr. Pappas was amended and restated again with no fixed term.  On December 20, 2018, Mr. Pappas’ employment agreement was amended to remove his 280G gross-up provision and amended the Company.term of his agreement to be one to three months after his successor was employed. 2019 Proxy Statement        47 Table of Contents EXECUTIVE COMPENSATION Mr. Niziolek entered into an employment agreement with the Company on June 13, 2016 with an initial term of one year, and subject to automaticone-year extensions beginning on the expiration of the initial term. The automatic extension of the agreement may be terminated with at least 90 days’ prior written notice from Mr. Niziolek or the Company stating their intent not to extend the employment term. Messrs. Pugh, Stedman and Yarkadas have also entered into employment agreements with us with employment dates commencing on March 1, 2013 in the case of Mr. Pugh, and November 1, 2015 in the case of Messrs. Stedman and Yarkadas. Mr. Pugh’s employment agreement expired on the effective date of his retirement, March 1, 2017.2015. The employment agreements with Messrs. Stedman and Yarkadas have no fixed term but their agreements may be terminated by either party providing at least six months’ prior written notice of the intent to terminate. Mr. Chaclas entered into an employment agreement with the Company with effective date commencing on January 1, 2015. The agreement provides for an initial term of three years and is subject to automatic one-year extensions beginning on the expiration of the initial term. The automatic extension of the agreement may be terminated with at least 90 days' prior written notice from Mr. Chaclas or the Company stating the intent not to extend the employment term. Under his employment agreement Mr. Pappas iswas entitled to receive an annual base salary of $1,100,000 in 2016, $1,150,000 in 2017, and $1,200,000 in 2018 under his employment agreement. Under$1,200,000. Based on their agreements, Messrs. Pugh, Niziolek, Stedman, Yarkadas, and YarkadasChaclas are entitled to receive annual base salaries in 20162018 of $530,000, CHF 600,000, $500,000,480,000, CHF 450,000480,000 and CHF 450,000,$435,000, respectively. These salaries are subject to annual review by the Board (or a committee thereof) during the first 90 days of each calendar year, and the base salary in respect of such calendar year may be increased above, but not decreased below, its level for the preceding calendar year. Each NEO is also entitled to participate in our employee and fringe benefit plans as may be in effect from time to time on the same general basis as our other employees. 34 2017 Proxy Statement EXECUTIVE COMPENSATION Under their employment agreements, Messrs. Pappas, Pugh, Niziolek, Stedman, Yarkadas, and YarkadasChaclas had target bonus opportunities under our annual cash incentive plan equal to 150%, 75%, 70%, 60%65%, 65%, and 60%65%, respectively, of their base salaries. For 2016,2018, these payouts were paid abovebelow target, but belowprimarily due to the plan maximum of 200%.Company’s financial performance versus target for the year. See “Compensation Discussion and Analysis—2018 Compensation Elements—AnnualStructure and Performance —Annual Cash Incentive Plan” for additional details on how the cash incentive awards were determined. Additionally, under their employment agreements, Messrs. Stedman and Yarkadas are entitled to staggered signing bonuses to be paid on the first, second, and third anniversaries of their employment, and are contingent on their continued employment through the respective anniversary date. These staggered signing bonuses were negotiated by the executives to compensate them for forfeited equity compensation that they would have received had they stayed with their previous employers. For 2016,2018, Messrs. Stedman and Yarkadas receivedlump-sum gross payments of CHF 455,000 and CHF 200,000, respectively. Subject to their continued employment for 2017 and 2018, Mr. Stedman will be entitled to his remaining staggered signing bonuses of CHF 455,000 and CHF 255,000 and Mr. Yarkadas will be entitled to his remaining staggered signing bonuses of CHF 280,000 and CHF 340,000, respectively.respectively, which represented the final signing bonus installment under their employment agreements. Under his employment agreement, Mr. Stedman iswas required to relocate to the Zurich, Switzerland metropolitan area on the earlier of September 30, 2018, or the date his spouse relocatesrelocated to this area. At the time of his relocation, which occurred in 2018, Mr. Stedman will bewas eligible to receive relocation services. For fiscal 2016,2018, Mr. Stedman received an aggregate stipend of $72,720$55,315 for living expenses and $51,036$22,440 in taxgross-ups related theseto this living expenses.expense stipend. Until the earlier of September 30, 2018 or the date his spouse relocatesrelocated to Zurich, Mr. Stedman receivesreceived a monthly allowance of CHF 6,000(grossed-up (grossed-up for tax at the marginal rate) for incidental living expenses while living in Zurich. During this period Mr. Stedman iswas also entitled to the reimbursement of the fare for one economy class flight taken per week between Switzerland and the United Kingdom. During 20162018 Mr. Stedman received $7,125$5,192 in such commuting reimbursements. For 2019, Mr. Stedman will not be entitled to any further living or commuting costs. 48        2019ProxyStatement Table of Contents EXECUTIVE COMPENSATION As part of his relocation to Zurich, Switzerland, the Company, under Mr. Yarkadas’ employment agreement, pays the tuition for the international school education,grossed-up for tax at the marginal rate, for a period of 4 and 7 years for his oldest and youngest child, respectively. For fiscal 2016,2018, the Company paid $89,765$86,030 in tuition for Mr. Yarkadas’ children for which Mr. Yarkadas also received $58,175$25,206 in tax gross-ups. gross-ups.Prior to becoming part of our executive leadership team, Mr. Chaclas was eligible to participate in incentive programs not available to our other NEOs. Mr. Chaclas participated in the Company's 2013 and 2014 Long-Term Incentive Plan. These Long-Term Incentive Plans were designed to provide long-term incentives to our employees who did not receive long-term incentive compensation in the form of equity awards in our former parent, Bain Capital Everest Manager Holding SCA. Each Long-Term Incentive Plan set three-performance year Adjusted EBITDA targets with each year having equal weighting. See “Compensation Discussion and Analysis – 2018 Compensation Structure & Performance – Annual Cash Incentive Plan” for more information as to how the Company calculates its Adjusted EBITDA targets with respect to its incentive plans. The payout factor was determined by averaging the actual payout percentage approved by the compensation committee for each performance year. The cash incentive for these plans was paid out in the year following the last annual EBITDA target for each plan.  These plans resulted in cash awards to Mr. Chaclas of $130,267 and $158,292 in 2016, and 2017, respectively. Each of our NEOs participated in our 2014 Omnibus Incentive Plan. For 2016,2018, Messrs. Pappas, Pugh, Niziolek, Stedman, Yarkadas and YarkadasChaclas received an annual target equity incentive award under the plan of 450%480%, 175%, 155%135%, 100%135%, and 100%140%, respectively, of their base salaries. The value of the equity award is split among stock options (30%), RSUs (30%), and PSUs (40%). Additionally, on September 14, 2018, both Messrs. Stedman and Yarkadas were granted an equity retention award with a grant value of $1.3 million and consisting of 50% PSUs and 50% restricted stock units RSUs. See “Compensation Discussion and Analysis—2018 Compensation Structure and Performance—Long-Term Equity Incentive Compensation” for more information about the compensation committee’s practices and philosophy with respect to these awards. The RSUs will vest in full on the third anniversary of the grant date, generally split evenlysubject to the executive’s continued employment with the Company. The PSUs will vest on the third anniversary of the grant date, subject generally to the executive’s continued employment and to the Company’s relative total shareholder return (“TSR”) performance, assuming the reinvestment of dividends, against the performance of 48 other chemical companies with shares traded on a major U.S. stock exchange and that have a market capitalization exceeding $500 million dollars at the time the award is granted. The threshold, target and maximum payout, which represents the 25th, 50th, and 75th percentile of TSR performance relative to peers, would be 50%, 100%, and 200% of the PSU award’s target amount, respectively. The number of PSUs ultimately vested will be interpolated between RSUsthe 25th and options.50th percentiles and between the 50th and 75th percentiles. Regardless of the foregoing targets, vesting of the PSUs is capped at 100% of target if the Company’s TSR is negative for the three-year performance period. Additionally, the total value of the awards delivered at vesting is capped at three times the target shares multiplied by the grant date share price. Because the Company assumes reinvestment of dividends, dividend equivalents accrue during the performance period. However, dividend equivalents will be paid only if, and to the extent, the PSUs vest.  The option awards issued under the 2014 Omnibus Incentive Plan, which contain an exercise term of nine years from the grant date, vest in three equal annual installments beginning on the first anniversary the grant date, generally subject to the employee remaining continuously employed on the applicable vesting date. Upon a termination of employment due to the employee’s death or retirement or a termination of employment by the Company without cause in connection with a restructuring or redundancy or due to the employee’s disability prior to a vesting date, the options will vest in full or will continue to vest on the original vesting schedule, 2019 Proxy Statement        49 Table of Contents EXECUTIVE COMPENSATION depending on the type of termination. In the event employmentthe employee voluntarily resigns or is terminated for cause, all vested and unvested options will be forfeited. RSUs granted under the 2014 Omnibus Incentive Plan vest in full on third anniversary of the grant date, generally subject to the employee remaining continuously employed by the Company on the vesting date. Upon a termination of employment due to the employee’s death or retirement or a termination of employment by the Company without cause in connection with a restructuring or redundancy or due to the employee’s disability prior to the vesting date, the RSUs will vest in full or in part, depending on the type of termination. In the event employmentthe employee voluntarily resigns or is terminated for cause, all unvested RSUs will be forfeited. Prior to November 2016, dividend and dividend equivalents did not accumulate on unvested RSUs. In November 2016, the board of directors approved an amendment to all outstanding RSUs, entitlingBeginning in 2017, each award holder to anwas entitled amount equal to any cash dividend or repayment of equity paid by the Company upon one ordinary share for each RSU held by the award holder (“dividend equivalents”) beginning in 2017.. Award holders have no right to receive the dividend equivalents unless and until the associated RSUs vest. The dividend equivalents will be payable in cash and will not accrue interest. PSUs granted under the 2014 Omnibus Incentive Plan will vest on the third anniversary of the grant date, subject to the Company’s relative TSR performance, assuming the reinvestment of dividends, against the performance of 49other chemical companies with shares traded on a major U.S. stock exchange and that have a market capitalization exceeding $500 million dollars at the time the award is granted. The amount of PSUs that will vest are generally as follows: 2017 Proxy Statement Trinseo Percentile Ranking Relative to Peer Group % of Target Shares Vested* Under 25th percentile 0 % 35 25th percentile 50 % 50th percentile 100 % 75th percentile 200 % EXECUTIVE COMPENSATION*     Vesting is interpolated between the 25th and 50th and between the 50th and 75th percentiles Regardless of the targets above, vesting is capped at 100% of target if the Company’s TSR is negative for the performance period. Additionally, the total value of the awards delivered at vesting is capped at three times the target shares multiplied by the grant date share price. Because we assume reinvestment of dividends, dividend equivalents accrue during the performance period. However, dividend equivalents will be paid only if and to the extent the PSUs vest, since we do not believe the executives should receive the benefit of such dividend earnings if the performance criteria associated with the PSU award is otherwise not met. Upon a termination of employment due to the employee’s death or retirement or a termination of employment by the Company without cause in connection with a restructuring or redundancy or due to the employee’s disability prior to the vesting date, PSUs will vest in full or in part, depending on the type of termination. In the event the employee voluntarily resigns or is terminated for cause, all unvested PSUs will be forfeited.   50        2019ProxyStatement Table of Contents EXECUTIVE COMPENSATION Outstanding Equity Awards at FiscalYear-End Table The table below sets forth certain information regarding outstanding and unvested equity awards held by the NEOs as of December 31, 2016.2018. The awards below represent RSUs, PSUs, and options issued under our 2014 Omnibus Incentive Plan.                                         Option Awards   Stock Awards             Equity               Equity Incentive             Incentive Plan           Equity Incentive   Plan Awards:             Awards:           Plan Awards:   Market or Payout         Number of   Number of           Number of   Value of         Securities   Securities           Unearned Shares,   Unearned Shares,         Underlying   Underlying   Option       Units, or Other   Units or Other         Unexercised   Unexercised   Exercise   Option   Rights that  have   Rights  that     Grant   Options (#)   Options (#)(1)   Price   Expiration   Not   have Not Vested Name   Date   Exercisable   Unexercisable   ($)   Date   Vested (#)(4)   ($)(3) Christopher D. Pappas     2/22/2018     —     77,385     81.20     2/22/2027     49,655     $ 2,273,206     2/16/2017   26,223   52,446   71.45   2/16/2026   52,954   $ 2,424,234     2/22/2016   81,179   81,140   26.97   2/22/2025   91,769   $ 4,201,185     2/27/2015   91,891       18.14   2/27/2024   —   $ — Barry J. Niziolek   2/22/2018   —   12,461   81.20   2/22/2027   7,996   $ 366,057     2/16/2017   3,948   7,896   71.45   2/16/2026   7,973   $ 365,004     6/22/2016   18,269   9,135   47.45   6/22/2025   8,167   $ 373,885 Timothy M. Stedman   9/14/2018   —               17,344     794,008     2/22/2018       9,341   81.20   2/22/2027   5,994   $ 274,405     2/16/2017   2,650   5,301   71.45   2/16/2026   5,353   $ 245,060     2/22/2016   7,510   7,510   26.97   2/22/2025   8,494   $ 388,855 Hayati Yarkadas   9/14/2018   —               17,344   $ 794,008     2/22/2018   —   9,341   81.20   2/22/2027   5,994   $ 274,405     2/16/2017   2,650   5,301   71.45   2/16/2026   5,353   $ 245,060     2/22/2016   15,020   7,510   26.97   2/22/2025   8,494   $ 388,855 Angelo N. Chaclas   2/22/2018   —   8,182   81.20   2/22/2027   5,250   $ 240,345     2/16/2017   2,751   5,502   71.45   2/16/2026   5,556   $ 254,354     2/22/2016   -   7,992   26.97   2/22/2025   9,038   $ 413,760     2/27/2015   7,892   —   18.14   2/27/2024   —   $ —               Option Awards      Stock Awards   Name    Grant Date      Number of Securities Underlying Unexercised Options (#) Exercisable      Equity Incentive Plan Awards: Number of Securities Underlying Unexercised Options (#)(1) Unexercisable      Option Exercise Price ($)      Option Expiration Date      Equity Incentive Plan Awards: Number of Unearned Shares, Units, or Other Rights that have Not Vested (#)(2)      Equity Incentive Plan Awards: Market or Payout Value of Unearned Shares, Units or Other Rights that have Not  Vested ($)(3)   Christopher D. Pappas      2/22/2016        —        243,419        26.97        2/22/2025        —        —        2/22/2016        —        —        —        —        91,769      $ 5,441,902        2/27/2015        90,797        181,594        18.14        2/27/2024        —        —        2/27/2015        —        —        —        —        115,776      $ 6,865,517   Martin Pugh      2/22/2016        —        52,569        26.97        2/22/2025        —        —        2/22/2016        —        —        —        —        19,819      $ 1,175,267        2/27/2015        19,314        38,630        18.14        2/27/2024        —        —          2/27/2015        —        —        —        —        24,626      $ 1,460,322   Barry J. Niziolek      6/22/2016        —        27,404        47.45        6/22/2025        —        —          6/22/2016        —        —        —        —        8,167      $ 484,303   Timothy M. Stedman      2/22/2016        —        22,530        26.97        2/22/2025        —        —          2/22/2016        —        —        —        —        8,494      $ 503,694   Hayati Yarkadas      2/22/2016        —        22,530        26.97        2/22/2025        —        —          2/22/2016        —        —        —        —        8,494      $ 503,694   (1) (1) Option awards vest in three equal installments beginning on the first anniversary of the grant date. (2) (2) This column represents unvested RSUs. All RSU awards vest in full on the third anniversary of the grant date. (3) (3) The market value of the RSU awards was calculated using the Company’s closing stock price on December 30, 201631, 2018 of $59.30.$45.78. (4) These columns represent unvested and unearned RSUs and PSUs. All RSU and PSU awards vest in full on the third anniversary of the grant date, subject to achieving certain performance conditions. The number of the RSUs and PSUs that vest upon completion of the service period can range from 0 to 200% of the original grant. The number of unvested RSUs and PSUs was calculated using 100% assumed achievement. Options Exercised and Shares Vested Table During 2016, no options were exercised by our NEOs and no awards held by our NEOs in shares of our Company’s publicly traded equity vested. The following table shows the number of ordinaryoptions exercised and the number of shares acquired by Messrs. Pappas and Pugh uponthrough the vesting of restricted shares ofRSU awards by our ParentNEOs during fiscal year 2016:2018.                              Option Awards      Share Awards                           Number of   Value Realized   Number of Shares   Value Realized     Options Exercised   on Exercise   Acquired on Vesting   on Vesting Name      (#)      ($)(1)       (#)      ($) Christopher D Pappas   —   $ —   115,776   $ 9,453,110 Barry J. Niziolek   —   $ —   —   $ — Timothy M. Stedman   —   $ —   —   $ — Hayati Yarkadas   —   $ —   —   $ — Angelo N. Chaclas   7,991   $ 440,531   10,061   $ 821,481        Share Awards   Name    Number of Shares Acquired on Vesting (#)(1)      Value Realized on Vesting ($)(2)   Christopher D. Pappas      53,254      $ 12,089,962   Martin Pugh      12,392      $ 2,973,690   (1) From 2010 through 2013, our former Parent granted various time-based and performance-based restricted stock awards to certain key members of management. All share awards acquired on vesting above are with respect to these stock awards of our former Parent’s ordinary shares. With (1) Represents the adoptiondifference between the fair market value of the Company’s 2014 Omnibus Plan, discussed above, restricted stock awards have not been issued byshares acquired and the former Parent on behalf of the Company. During 2016, our former Parent completed the sale of its ordinary shares of the Company through secondary offerings, and as a result, no longer holds any ownership interest in the Company. Pursuant to this sale, under the terms of the related security holder agreements for these awards, vesting of all outstanding restricted stock awards was fully accelerated during 2016.option cost. (2) The value realized on vesting is based on the fair value per share of our Parent’s ordinary shares on the date of vesting. 36 2017 Proxy Statement EXECUTIVE COMPENSATION   2019 Proxy Statement        51 Table of Contents EXECUTIVE COMPENSATION U.S.Non-Qualified Deferred Compensation Table The following table summarizes the activity during 2016,2018, as well as theyear-end account balances, in ournon-qualified savings and deferred compensation plan for Mr. Pappas. Mr.Messrs. Pappas, Niziolek, was not eligible to participate in this plan until January 2017.and Chaclas. Messrs. Pugh, Stedman and Yarkadas are based in Switzerland and did not participate in this plan. The plan allows eligible employees, including the NEOs, to defer a portion of their compensation (up to 75% of base salary and up to 100% of annual cash incentive awards) on apre-tax basis with a matching contribution from the Company, payable at a future date based on specific plan parameters. Additionally, the plan provides for discretionary company contributions in connection with earnings in excess of the limits under the Company’s 401(k) Plan. While the plan is unfunded, amounts deferred under the plan are credited with earnings based on the performance of selected investment vehicles that are available in the open market. The plan is available to all U.S. employees who satisfy certain eligibility requirements, including the NEOs. An eligible participant can elect to receive a distribution under the plan in the form of a lump sum payment upon separation from service with the Company. Additionally, a participant may elect to receive a distribution at a specified future date in either a single lump sum or a series of annual installments over a period of 5 to 10 years. However, this latter distribution option is only available for the elective deferral of a participant’s base salary and annual cash incentive award. Company matching and discretionary contributions must be paid as a lump sum at separation from employment.                                                                   Aggregate              Executive   Company   Aggregate   Withdrawals/   Aggregate     Contributions   Contributions   Earnings   Distributions   Balance as of Name   in 2018 ($)(1)   in 2018 ($)(2)   in 2018 ($)(3)   in 2018 ($)   December 31, 2018($)(4) Christopher D. Pappas   $  248,350   $  143,075   $  620,846   $  —   $ 2,970,618 Barry J. Niziolek   $  —   $ 43,950   $ 505   $  —   $  44,455 Angelo N. Chaclas   $  —   $ 32,948   $ 4,653   $  —   $ 91,055   Name    Executive Contributions in 2016 ($)(1)      Company Contributions in 2016 ($)(2)      Aggregate Earnings in 2016 ($)(3)      Aggregate Withdrawals/ Distributions in 2016 ($)      Aggregate Balance as of December 31, 2016 ($)(4)   Christopher D. Pappas    $ 88,000      $ 158,050      $ 144,257      $ —      $ 1,763,230   (1) (1) Represents amountsthe amount contributed by Mr. Pappas under thenon-qualified savings and deferred compensation plan. These amounts areThis amount is included in the Summary Compensation Table as part of “Salary.”“Salary”.   (2) (2) Includes matching and discretionary amounts that were contributed by the Company under thenon-qualified savings and deferred compensation plan. These amounts are also included in the Summary Compensation Table in the “All Other Compensation” column. (3) (3) Represents earnings on account balances under the Company’snon-qualified savings and deferred compensation plan. Amounts are not reported as compensation in the Summary Compensation Table. (4) (4) Includes amounts that were reported as compensation in the Summary Compensation Table in 20162018 and prior years to the extent such amounts were contributed by the executive and the Company, but not to the extent that such amounts represent earnings. Pension and Other Postretirement Benefits Switzerland Retirement Plan The Switzerland retirement plan is a fully insured defined contribution pension plan. Future retirement benefits are calculated based on accumulated savings at retirement, which consists of savings contributions made by the employee and the Company, and an annually credited interest rate that is contingent upon investment results. Actual retirement benefits will be dependent on investment results, actual rate of interest applied on the savings capital, potential future changes in plan regulation and/or legal changes and future salary changes. The amount of pensionable salary is calculated using base pay plus the annual target bonus amount minus a coordination amount that reflects the maximum social security pension in place at the time, and is subject to a statutory maximum. Employee and Company contributions are based on the employee’s age and determined in accordance with the percentage of pensionable salary as follows:                    Employee saving      Employer saving       contributions   contributions       in % of   in % of   Name   pensionable salary   pensionable salary   Timothy M. Stedman   8.00 %   8.00 % Hayati Yarkadas   8.00 %   8.00 % 52        2019ProxyStatement Table of Contents EXECUTIVE COMPENSATION   Name    Employee saving contributions in % of pensionable salary      Employer saving contributions in % of pensionable salary   Martin Pugh      10.00 %       10.00 %  Timothy M. Stedman      8.00 %       8.00 %  Hayati Yarkadas      8.00 %       8.00 %  In addition, the Company pays the total premiums for risk benefits and other costs. Benefits are paid as a monthly annuity, lump sum or a combination of these two payment forms. Supplemental Employee Retirement Benefit In 2010, we entered into an employment contract with Mr. Pappas which included a provision fornon-qualified supplemental employee retirement benefits. Mr. Pappas is 100% vested in these benefits and the accrued benefits, willif not subject to Section 409A, would otherwise be due to be paid to Mr. Pappas in 2017 Proxy Statement 37 EXECUTIVE COMPENSATION a lump sum within 30 days after his termination of employment. The amount payable to Mr. Pappas with respect to his supplemental employee retirement benefits is determined based on his years of Service Credit and his average base salary and target bonus for the three full calendar years prior to his termination. The accrued benefits are equal to the Basic Percentage times the average of his base salary plus target bonus for the three full calendar years prior to his termination (the “Final Average Pay”) plus the Supplemental Percentage times the Final Average Pay reduced by the36-month 36‑month rolling average Social Security Taxable Wage Base as of the date of termination. The Basic Percentage and Supplemental Percentage are determined based on Mr. Pappas’ years of Service Credit, which are 425% and 120%, respectively.  The employment agreement with our new Chief Executive Officer and President, Mr. Bozich does not provide for any non-qualified supplemental employee retirement plan benefits.  The following table shows the actuarial present value of accumulated pension and other post-retirement benefits as of December 31, 2016:2018:                                     Number of      Present                  Years of   Value of   Payments         Credited   Accumulated   During Name   Plan Name   Service (#)(1)   Benefit ($)(2)   2018 ($) Christopher D. Pappas   Supplemental Employee Retirement Plan   30.0   $ 15,039,355   $  — Barry J. Niziolek   N/A    —   $  —   $  — Timothy M. Stedman   Switzerland Retirement Plan   3.5   $ 652,517   $  — Hayati Yarkadas   Switzerland Retirement Plan   3.5   $ 662,761   $  — Angelo N. Chaclas   N/A    —   $  —   $  —   Name    Plan Name    Number of Years of Credited Service (#)(1)      Present Value of Accumulated Benefit ($)(2)      Payments During 2016 ($)   Christopher D. Pappas    Supplemental Employee Retirement Plan      30.0      $ 13,784,371      $ —   Martin Pugh    Switzerland Retirement Plan      10.5      $ 2,155,364      $ —   Barry J. Niziolek    N/A      —      $ —      $ —   Timothy M. Stedman    Switzerland Retirement Plan      1.5      $ 163,198      $ —   Hayati Yarkadas    Switzerland Retirement Plan      1.5      $ 162,184      $ —   (1) (1) The years of credited service for Mr. Pappas are determined pursuant to his employment agreement, under which he was granted 6 years of Service Credit at the start of his employment and on each anniversary date, until he reached a maximum of 30 years. Mr. Pugh’s years of credited service include years that he was employed by a prior company, as required by Swiss law. (2) (2) The inputs and assumptions used to determine the present value of accumulated benefits are provided in the table below. These assumptions are consistent with the assumptions set forth in Note 16 to the 20162018 consolidated financial statements filed with our Annual Report on Form10-K. 10‑K.                    Discount rate      Salary increase*   Supplemental Employee Retirement Plan   3.19 %   *   Switzerland Retirement Plan   0.89 %   2.25%          Discount rate      Salary increase*   Supplemental Employee Retirement Plan      1.37 %               *  Switzerland Retirement Plan      0.67 %       2.00 %  *      The salary increase assumption for Mr. Pappas under the Supplemental Employee Retirement Plan were the actual salary increases set forth in his employment agreement. * The salary increase assumption for Mr. Pappas under the Supplemental Employee Retirement Plan were the actual salary increases set forth in his employment agreement. Payments upon Termination or Change in Control Messrs. Pappas, Niziolek, and NiziolekChaclas In the event of an executive’s termination of employment for any reason, Messrs. Pappas, Niziolek, and NiziolekChaclas will each be entitled to receive any unpaid base salary through the date of termination and all accrued and vested benefits under our vacation and other benefit plans and, except in the case of a termination by us for “cause” or by the executive without “good reason” (each, as defined in the executive’s employment agreement), (i) any annual bonus earned but unpaid with respect to the calendar year ending on or preceding the date of termination and (ii) a pro rata target bonus for the calendar year of termination. Under Mr. Pappas’ agreement, in the event 2019 Proxy Statement        53 Table of his voluntary termination of employment without “good reason,” he shall provide the Company with one year’s written notice. In the event his termination date is less than one year following his written notice of termination, Mr. Pappas would not receive the pro rata target bonus for the calendar year of termination.Contents EXECUTIVE COMPENSATION In addition to the severance benefits described above, upon termination of an executive without “cause” or by the executive for “good reason,” the executive will be entitled to receive the following severance benefits, subject to the executive’s timely execution of a general release of claims. In the case of Mr. Pappas, he will bein the event of his termination by the Company prior to January 1, 2019 without "cause" and with at least four months' advance notice, Mr. Pappas would have been entitled to receive 2.0a severance amount equal to the remainder of his 2018 base salary and his target bonus. In the event of his termination by the Company prior to January 1, 2019 without at least four months' advance notice and without cause, Mr. Pappas would have received a severance amount equal to 1.0 times the sum of his annual base salary and target bonus,bonus. In the event Mr. Pappas terminated his employment for “good reason” prior to January 1, 2019, the Company would have had to pay a severance amount equal to 2.0 times his annual base salary and target bonus. On or after January 1, 2019, in the event the Company terminated Mr. Pappas’ employment without notice other than for cause or Mr. Pappas terminates his employment for “good reason”, he would have been entitled to a severance amount equal to 1.0 times his annual base salary and target bonus. In the event the Company terminated  Mr. Pappas’ employment on or after January 1, 2019 with two months' advance notice and without cause, Mr. Pappas would not have been entitled to any additional severance. Mr. Pappas would have been entitled to receive the severance amounts described above payable in equal monthly installments over the 24 month12-month period following such termination, and,his termination. Additionally, if Mr. Pappas iswould be participating in the Company’s health plans at the time of his termination, he is eligible to receive continued health benefits for a period of 2412 months following such termination, provided, however, that if he obtains other employment that offers group health benefits, such continued insurance coverage will terminate. In the case of Mr.Messrs. Niziolek heand Chaclas, each will be entitled to receive (i) an amount equal to 1.5 times the sum of his respective base salary and target bonus, payable in equal monthly installments over the 18 month period following such termination, and 38 2017 Proxy Statement EXECUTIVE COMPENSATION (ii) 18 months of health benefits continuation, provided, however, that if he obtains other employment that offers group health benefits, such continued insurance coverage will terminate. To the extent that any executive experiences a termination of employment by us without “cause” or by the executive for “good reason” within two years following a “change in control” (as defined in the agreements), the cash severance benefits described above will be (or would have been) paid to such executive in a cash lump sum as opposed to in installments. In addition, in the case of Mr. Pappas, to the extent that the severance payments and benefits payable under his agreement would cause him to be liable for excise taxes by reason of the application of Sections 280G and 4999 of the Code, and the Company’s equity securities are publicly traded on an established securities market in accordance with Section 280G, Mr. Pappas will be entitled to an additional “gross up” payment to indemnify him for the effect of the excise taxes. For Mr.Messrs. Niziolek and Chaclas, to the extent that any payments that are considered to be contingent on a change in control would be subject to Sections 280G and 4999 of the Code, such payments will be limited if the net benefit to him on anafter-tax basis would be greater than receiving the full value of all payments and paying the excise tax. The amounts in the table assume that the full amounts were paid to the executives, without any limitation. To the extent that any portion of either Messrs. Pappas’, Niziolek’s, or Niziolek’sChaclas' severance amount due to a termination of employment by us without “cause” or by the executive for “good reason” constitutes nonqualified deferred compensation for purposes of Section 409A of the Internal Revenue Code, any payment scheduled to occur during the first 60 days following his termination of employment shall not be paid until the 60th day following his termination. The agreements with Messrs. Pappas and Niziolek contain anon-competition covenant that prohibits the executive from competing against us for a period of two years, in the case of Mr. Pappas, and a period of one year, in the case of Mr.Messrs. Niziolek and Chaclas, following termination of employment. These agreements also containnon-solicitation provisions that prohibit the executive from actively soliciting our employees, customers or suppliers during the period of employment and for a period of two years, in the case of 54        2019ProxyStatement Table of Contents EXECUTIVE COMPENSATION Mr. Pappas, and a period of one year, in the case of Mr.Messrs. Niziolek and Chaclas, following termination of employment. The executives are also subject to perpetual confidentiality restrictions that protect our proprietary information, developments and other intellectual property. Messrs. Pugh, Stedman and Yarkadas In the event of termination of his employment for any reason, Messrs. Pugh, Stedman and Yarkadas will each be entitled to receive any unpaid base salary through the date of termination and all accrued and vested benefits under our vacation and other benefit plans and, except in the case of a termination by us for “cause” or by him without “good reason” (each, as defined in his employment agreement)the executive (i) any annual bonus earned but unpaid with respect to the calendar year ending on or preceding the date of termination; and (ii) an amount equal to thepro-rata portion of his target bonus for the calendar year of termination. Messrs. Stedman and Yarkadas will also each receive payments required by applicable law upon a termination by reason of disability, as described in the table below. In addition to the severance benefits described above, upon either Messrs. Stedman’s or Yarkadas’ termination by us without “cause” or by him for “good reason,”, Messrs. Stedman and Yarkadas will each be entitled to receive the following severance benefits, subject to his timely execution of a general release of claims in an amount equal to 1.5 times the sum of his annual base salary and target bonus. To the extent that either executive experiences a termination of employment by us without “cause” or by him for “good reason” within two years following a “change in control” (as defined in his agreement), the cash severance benefits described above will be paid to him in a cash lump sum as opposed to in installments. Mr. Pugh retired effective March 1, 2017. His agreement contained virtually identical terms to those of Messrs. Stedman and Yarkadas, with respect to his termination for cause or with good reason, as well as in the event of a change in control. Under the first amendment to his employment agreement, Mr. Pugh was eligible to receive a retirement allowance of $202,138 which was paid in March 2017. The agreements for Messrs. Pugh, Stedman, and Yarkadas each contain anon-competition covenant that prohibits each executive from competing against us for a period of 18 months following his termination of employment. The agreement also containsnon-solicitation provisions that prohibit each executive from actively soliciting our employees, customers or suppliers during the period of employment and for a period of 6 months following his termination. Each executive is also subject to perpetual confidentiality restrictions that protect our proprietary information, developments and other intellectual property. 2017 Proxy Statement 39 EXECUTIVE COMPENSATION Potential Payments The following table provides examples of the potential payments upon termination or upon a termination following a change in control to our NEOs, as if such event(s) took place on December 31, 20162018 (the last business day of our most recent fiscal year). The amounts reflected in this table were determined in accordance with each NEO’s then existing employment agreement. Amounts shown do not include (i) accrued but unpaid salary and vested benefits, including pension (as described above) and (ii) other benefits earned or accrued by the named executive officer during his or her employment that are available to all salaried employees and that do not discriminate in scope, terms or operations in favor of executive officers. With respect to any termination of employment, each NEO is entitled to receive accrued but unpaid base salary through the date of termination of employment, accrued but unpaid vacation and pension benefits (as described above) through such date, and, in the case of a termination due 2019 Proxy Statement        55 Table of Contents EXECUTIVE COMPENSATION to death, earned but unpaid bonus, if any, for the immediately preceding calendar year and apro-rata bonus for the year of termination.                                                                                                     Value of                        Cash   Health and   Previously   Value of       Cash         Separation   Welfare   Unvested   Insurance   2018   Separation     Termination   Payment   Benefits   Equity   Benefit   Target   Payment Name   Trigger   ($)(1)   ($)(2)   Awards (3)   ($)(4)   Cash Comp   Multiple Christopher D. Pappas   Termination for Cause   $  —   $  —   $  —   $  —   $  —   —     Termination Without Cause (>= 4 months notice)   $ 1,800,000   $ 21,306   $ 6,687,813   $  —   $  —   —     Termination Without Cause (< 4 months notice)     3,000,000     21,306     6,687,813      —     3,000,000   1     Good Reason     6,000,000     21,306     6,687,813      —     3,000,000   2     Death   $  —   $  —   $ 9,365,873   $ 500,000   $  —   —     Disability   $  —   $ 21,306   $ 9,365,873   $ 250,000   $  —   —     Change in Control(5)   $ 6,000,000   $ 21,306   $ 10,877,595   $  —   $ 3,000,000   2 Barry J. Niziolek   Termination for Cause   $  —   $  —   $  —   $  —   $           Termination Without Cause   $ 1,351,500   $ 16,614   $ 476,484   $  —   $ 901,000   1.5     Death   $  —   $ 0   $ 920,128   $ 500,000   $ —    —     Disability   $  —   $ 16,614   $ 920,128   $ 250,000   $ —    —     Change in Control   $ 1,351,500   $ 16,614   $ 1,157,667   $  —   $ 901,000   1.5 Timothy M. Stedman   Termination for Cause   $  —   $  —   $  —   $  —   $  —   —     Termination Without Cause   $ 1,216,940   $  —   $ 677,031   $  —   $ 811,293   1.5     Death   $  —   $  —   $ 1,369,855   $  —   $  —   —     Disability   $  —   $  —   $ 1,369,855   $  —   $  —   —     Change in Control   $ 1,216,940   $  —   $ 1,895,203   $  —   $ 811,293   1.5 Hayati Yarkadas   Termination for Cause   $  —   $  —   $ 0   $  —   $ —    —     Termination Without Cause   $ 1,216,940   $  —   $ 677,031   $  —   $ 811,293   1.5     Death   $  —   $  —   $ 1,369,855   $  —   $ —    —     Disability   $  —   $  —   $ 1,369,855   $  —   $ —    —     Change in Control   $ 1,216,940   $  —   $ 1,895,203   $  —   $ 811,293   1.5 Angelo N. Chaclas   Termination for Cause   $  —   $  —   $  —   $  —   $  —   —     Termination Without Cause   $ 1,076,625   $ 13,398   $ 664,990   $  —   $ 717,750   1.5     Death   $  —   $  —   $ 945,275   $ 500,000   $  —   —     Disability   $  —   $ 13,398   $ 945,275   $ 250,000   $  —   —     Change in Control   $ 1,076,625   $ 13,398   $ 1,104,658   $  —   $ 717,750   1.5   Name      Termination Trigger      Cash Separation Payment ($)(1)        Health and Welfare Benefits ($)(2)        Value of Previously Unvested Equity Awards (3)        Value of Insurance Benefit ($)(4)        280G Gross-Up ($)(5)       Christopher D. Pappas      Termination for Cause      $   —          $   —          $   —          $   —          $   —          Termination Without Cause      $   5,500,000          $   30,050          $   21,051,378          $   —          $   —          Death      $   —          $   —          $   27,651,564          $   500,000          $   —          Disability      $   —          $   30,050          $   27,651,564          $   250,000          $   —            Change in Control      $   5,500,000          $   30,050          $   27,651,564          $   —          $   4,039,324   (6)    Martin Pugh      Termination for Cause      $   —          $   —          $   —          $   —          $   —          Termination Without Cause      $   1,590,750          $   —          $   4,508,448          $   —          $   —          Death      $   —          $   —          $   5,925,155          $   —          $   —          Disability      $   —          $   —          $   5,925,155          $   —          $   —            Change in Control      $   1,590,750          $   —          $   5,925,155          $   —          $   —       Barry J. Niziolek      Termination for Cause      $   —          $   —          $   —          $   —          $   —          Termination Without Cause      $   1,275,000          $   —          $   405,455          $   —          $   —          Death      $   —          $   —          $   809,041          $   500,000          $   —          Disability      $   —          $   —          $   809,041          $   250,000          $   —            Change in Control      $   1,275,000          $   —          $   809,041          $   —          $   —       Timothy M. Stedman      Termination for Cause      $   —          $   —          $   —          $   —          $   —          Termination Without Cause      $   1,090,800          $   —          $   868,310          $   —          $   —          Death      $   —          $   —          $   1,232,089          $   —          $   —          Disability      $   —          $   —          $   1,232,089          $   —          $   —            Change in Control      $   1,090,800          $   —          $   1,232,089          $   —          $   —       Hayati Yarkadas      Termination for Cause      $   —          $   —          $   —          $   —          $   —          Termination Without Cause      $   1,090,800          $   —          $   868,310          $   —          $   —          Death      $   —          $   —          $   1,232,089          $   —          $   —          Disability      $   —          $   —          $   1,232,089          $   —          $   —            Change in Control      $   1,090,800          $   —          $   1,232,089          $   —          $   —     (1) (1) Cash separation payments are generally payable in installments except for payments upon a change in control, which are generally payable in a lump sum. (2) Mr. Niziolek did not participate in our health and welfare benefit plans as of December 31, 2016. (2) Messrs. Pugh, Stedman and Yarkadas receive government sponsored health and welfare benefits, and therefore, do not participate in the Company’s health and welfare benefit plans. (3) (3) Represents the value associated with equity awards issued under our 2014 Omnibus Incentive Plan, described in “—“Narrative Disclosure to Summary Compensation Table and Grants of Plan-Based Awards Table” above. Equity awards underabove and dividend equivalents paid, as applicable on these awards. Under our 2014 Omnibus Incentive Plan, RSUs and options vest in full upon death, disability, or a change in control, and vest in part in certain circumstances when termination is without cause. PSUs vest in full upon a change in control, and vest in part upon death or disability.  The value of the equity awards granted under our 2014 Omnibus Incentive Plan was calculated using the Company’s closing stock price on December 31, 20162018 of $59.30.$45.78.  While the number of PSUs that vest can range from 0 to 200% of the original grant, the information in the table above was calculated presuming performance was at target, and therefore 100% of the original grant.  (4) (4) Represents the maximum value of insurance payable on death due to accident or dismemberment or in the event of permanent disability. The insurance death benefit would only be $250,000, where the executive’s death was due to a cause other than accident or dismemberment. Employees in Switzerland are not covered under the employee life insurance policy and only receive applicable social system death benefits. (5) 40 2017 Proxy Statement This termination scenario also includes termination by Mr. Pappas for “good reason”. EXECUTIVE COMPENSATION     (5) Mr. Pappas would be subject to theso-called golden parachute tax and entitled to an excise taxgross-up in the amount set forth above assuming a change of control and his accompanying termination of employment occurred on December 31, 2016. The amount above assumes that (a) Company equity award granted within one year of the change in control transaction were presumed to be in contemplation of the transaction, (b) all outstanding equity awards under our 2014 Omnibus Incentive Plan are cashed out in connection with the applicable event and valued using a price per share of $59.30 and (c) a marginal tax rate of 45% is applied. (6) The figure set forth above is calculated by including amounts that are not taxable as compensation for federal tax purposes and, accordingly, may not be subject to the excise tax imposed under Section 4999 of the U.S. Tax Code. As a result, the amount disclosed above may overstate the amount of any required gross up. 2017 Proxy Statement 41 56        2019ProxyStatement Table of Contents DIRECTOR COMPENSATION Director Compensation For 2016,each of our Company’snon-employee directors, our director compensation program provided each memberconsists of our Board who is not an employee of the Company or one of our subsidiaries an annual cash retainer payment of $90,000. Under this program eachnon-employee director was also eligible to receive$90,000, and an annual equity retainer of restricted stock units with a grant date fair value of $90,000,$120,000, which vest on theone-year anniversary of their grant date. Our director compensation program for 2016 also providedAdditionally, the Board’s non-employee chairperson receives an additional annual cash retainer payments for theof $100,000. The non-employee chairpersons of the audit committee, and compensation committee, and nominating and corporate governance committee receive additional annual cash retainers of $25,000, $15,000, and $15,000,10,000, respectively. Our directors are subject to the Company's share ownership guidelines, which stipulate that each director must hold five (5) times their annual cash retainer in Trinseo shares within five (5) years from January 1, 2016 or the date of becoming a Board member, whichever is earlier. The following table sets forth information concerning the compensation earned by our directors during fiscal 2016.2018. Compensation for Mr. Pappas is included with that of our other named executive officers. Mr. Pappas did not receive any additional compensation for his service on our Board.                                  Fees Earned                 All Other              or Paid in   Stock Awards   Compensation         Cash ($)(1)   ($)(2)(3)   ($)(4)   Total ($) Joseph Alvarado   $  90,000   $ 120,000   $  —   $ 210,000 Jeffrey J. Cote   $ 115,000   $ 120,000   $  —   $ 235,000 Pierre-Marie De Leener   $ 90,000   $ 120,000   $  —   $ 210,000 K’Lynne Johnson   $  90,000   $ 120,000   $  —   $ 210,000 Philip R. Martens   $ 90,000   $ 120,000   $  —   $ 210,000 Donald T. Misheff   $ 100,000   $ 120,000   $  —   $ 220,000 Henri Steinmetz   $  90,000   $ 120,000   $ 15,300   $  225,300 Stephen M. Zide   $  205,000   $ 120,000   $  —   $ 325,000        Fees Earned or Paid in Cash ($)(1)        Stock Awards ($)(2)(3)        Total ($)       Brian W. Chu      $   7,500          $   —          $   7,500       Jeffrey J. Cote      $   115,000          $   90,000          $   205,000       Pierre-Marie De Leener      $   90,000          $   90,000          $   180,000       Felix S. Hauser      $   47,069          $   90,000          $   137,069       Philip R. Martens      $   30,000          $   90,000          $   120,000       Donald T. Misheff      $   90,000          $   90,000          $   180,000       Michel G. Plantevin      $   90,000          $   90,000          $   180,000       Ruth Springham      $   30,000          $   —          $   30,000       Stephen F. Thomas      $   90,000          $   90,000          $   180,000       Aurélien Vasseur      $   60,000          $   —          $   60,000       Stephen M. Zide      $   105,000          $   90,000          $   195,000     (1) (1) Consists of annual retainer amounts, which are paid quarterly and prorated based on the director’s service dates. Mr. Chu resigned from our Board effective February 1, 2016 and was replaced by Mr. Hauser, effective February 22, 2016. Messrs. Hauser and Vasseur resigned from our Board effective September 1, 2016 and were replaced by Mr. Martens and Ms. Springham. (2) (2) The amounts reported represent the grant date fair value of restricted stock units granted in 20162018 calculated in accordance with ASC 718. The assumptions used for determining fair value are described in Note 17 to our consolidated financial statements filed with our Annual Report on Form10-K. 10‑K. (3) (3) As of December 31, 2016, Messrs. Cote, De Leener, Misheff, Plantevin, Thomas and Zide2018,  each of our non-employee directors held 1,8971,694 shares of the Company pursuant to their unvested restricted stock unit awards and Mr. Martens held 1,585 shares of the Company pursuant to his unvested restricted stock unit award. As of December 31, 2016, Messrs. Chu, Hauser, and Vasseur and Ms. Springham had no outstanding equity awards. (4) 42 2017 Proxy Statement The amounts for Mr. Steinmetz reflect the reimbursement of Value Added Tax they incurred for the provision of director services. SHAREHOLDER PROPOSALS AND DIRECTOR NOMINATIONS   2019 Proxy Statement        57 Table of Contents CEO PAY RATIO CEO Pay  Ratio As there were no significant changes to the global employee population nor significant changes to employee compensation arrangements, the Company used the same median employee for the 2018 CEO pay ratio calculation as used in 2017. The CEO pay ratio figures below are a reasonable estimate calculated in a manner consistent with SEC rules. CEO pay ratio figures below are a reasonable estimate calculated in a manner consistent with SEC rules. The Company determined that as of October 2, 2017, the total number of employees was 2,203. To identify the median employee, the Company chose target total cash compensation as the consistently applied compensation measure. To make this calculation, the Company annualized pay for those employees who commenced work during 2018 and any employee who was on unpaid leave for a portion of 2018.  The Company used a valid statistical sampling methodology to identify a population of employees whose target total cash compensation was within a 2% range of the median. From this sample, the Company identified the median employee and determined that person’s total compensation (determined in accordance with SEC rules) was $82,601. Therefore, as further described in the table below, the Company’s ratio of CEO pay to median worker pay is 105:1.                             Compensation Element      CEO      Median Employee Annual Salary   $ 1,200,000   $ 64,773 Overtime (OT), Double Time (DT), and Shift Differential (SD)   $  —   $ 10,796 Salary (including OT, DT and SD)   $ 1,200,000   $ 75,569 Fair Value of Stock Awards   $ 4,239,343   $  — Fair Value of Option Awards   $ 1,725,105   $  — Non-equity Incentive Plan Compensation   $ 843,750   $ 1,431 Change in Pension Value   $ 492,829   $  — All Other Compensation   $ 168,206   $ 5,359 Summary Compensation Table Totals   $ 8,669,233   $ 82,601 2018 CEO Pay Ratio     105:1 SEC rules for identifying the median employee allow companies to adopt a variety of methodologies, and to use reasonable estimates and assumptions that reflect their compensation practices. As such, pay ratios reported by other companies may not be comparable to the Company's pay ratio reported above. 58        2019ProxyStatement Table of Contents Shareholder Proposals & Director Nominations Shareholder Proposals and& Director Nominations A shareholder who intends to nominate a director or present a proposal at the 20182020 annual general meeting of shareholders and who wishes the nomination or proposal to be included in the proxy materials for that meeting pursuant toRule 14a-814a‑8 under the Securities Exchange Act of 1934, as amended, must submit the proposal in writing to us so that it is received by our Corporate Secretary no later than January 10, 2018.1, 2020. In addition, one or more shareholders representing at least ten percent (10%) of our ordinary shares outstanding may submit written proposals to the Company for inclusion on the agenda for the 20182020 annual general meeting of shareholders if such written proposals are received by the Company at least 21 days before our 20182020 annual general meeting of shareholders. Written proposals may be mailed to us at Trinseo S.A., 1000 Chesterbrook Boulevard, Suite 300, Berwyn, Pennsylvania 19312 Attn: Corporate Secretary. A shareholder who intends to nominate a director or present any other proposal at the 20182020 annual general meeting of shareholders but does not wish the proposal to be included in the proxy materials for that meeting must provide written notice of the nomination or proposal to us no earlier than 120 days and no later than 90 days before our 20182020 annual general meeting of shareholders. We reserve the right to reject, rule out of order, or take other appropriate action with respect to any proposal that does not comply with these and other applicable requirements. Our Articles of Association describe the requirements for submitting proposals at the annual general meeting. The notice must be given in the manner and must include the information and representations required by our Articles of Association. Householding SEC rules permit a single set of annual reports and proxy statements to be sent to any household at which two or more shareholders reside if they appear to be members of the same family. Each shareholder continues to receive a separate proxy card. This procedure is referred to as householding. While the Company does not household in mailings to its shareholders of record, a number of brokerage firms with account holders who are Company shareholders have instituted householding. In these cases, a single proxy statement and annual report will be delivered to multiple shareholders sharing an address unless contrary instructions have been received from the affected shareholders. Once a shareholder has received notice from his or her broker that the broker will be householding communications to the shareholder’s address, householding will continue until the shareholder is notified otherwise or until the shareholder revokes his or her consent. If at any time a shareholder no longer wishes to participate in householding and would prefer to receive a separate proxy statement and annual report, he or she should notify his or her broker. Any shareholder can receive a copy of the Company’s proxy statement and annual report by contacting the Company at its registered office at 26‑28, rue Edward Steichen, L‑2540 Luxembourg, Grand Duchy of Luxembourg, Attention: Secretary or by accessing it on the Company’s website at www.trinseo.com. Shareholders who hold their shares through a broker or other nominee who currently receive multiple copies of the proxy statement and annual report at their address and would like to request householding of their communications should contact their broker. 2019 Proxy Statement        59 Table of Contents Available Information Available Information Certain information in this proxy statement references sections of our 20162018 Annual Report onForm 10-K10‑K filed with the U.S. Securities Exchange CommissionSEC on March 1, 2017.February 28, 2019. The Company will provide, without charge, to each shareholder to whom a proxy statement is delivered, a copy off such information that is incorporated by reference, upon written or oral request. Requests will be responded to within one business day of receipt and materials will be sent via first class mail or another equally prompt means. Requests should be directed to: Attn: Investor Relations, 1000 Chesterbrook Blvd., Suite 300, Berwyn, Pennsylvania 19312 or (610) 240-3307.240‑3307.   60        2019ProxyStatement Table of Contents Annex 2017 Proxy Statement 43 TRINSEO S.A. 1000 CHESTERBROOK BLVD. SUITE 3000 BERWYN, PA 19312 VOTE BY INTERNET - www.proxyvote.com Use the Internet to transmit your voting instructions and for electronic delivery of information up untilinformation. Vote by 11:59 P.M. Eastern Time the day before the cut-off date or meeting date.ET on 11/18/2019. Have your proxy card in hand when you access the web site and follow the instructions to obtain your records and to create an electronic voting instruction form. ELECTRONIC DELIVERY OF FUTURE PROXY MATERIALS If you would like to reduce the costs incurred by our company in mailing proxy materials, you can consent to receiving all future proxy statements, proxy cards and annual reports electronically via e-mail or the Internet. To sign up for electronic delivery, please follow the instructions above to vote using the Internet and, when prompted, indicate that you agree to receive or access proxy materials electronically in future years. TRINSEO S.A. 26-28 RUE EDWARD STEICHEN L-2540 LUXEMBOURG GRAND DUCHY OF LUXEMBOURG LUXEMBOURG VOTE BY PHONE -1-800-690-6903 Use any touch-tone telephone to transmit your voting instructions up untilinstructions. Vote by 11:59 P.M. Eastern Time the day before the cut-off date or meeting date.ET on 11/18/2019. Have your proxy card in hand when you call and then follow the instructions. VOTE BY MAIL Mark, sign and date your proxy card and return it in the postage-paid envelope we have provided or return it to Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood, NY 11717. TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS: KEEP THIS PORTION FOR YOUR RECORDS — — — — —  —  — —  — —  — —  —  — —  — — —  —  —  —  —  —  —  —  —  —  —  —  —  —  —  —  —  —  — — —  DETACH AND RETURN THIS PORTION ONLY THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED. For Withhold For All AllAllExcept To withhold authority to vote for any individual nominee(s), mark “For All Except” and write the number(s) of the nominee(s) on the line below. The Board of Directors recommends you vote FORthe following:        1. To elect one Class III director, Mr. Henri Steinmetz,two additional directors specifically named in the proxy statement, each to serve for a term until the 2020 Company's next annual general meeting of shareholders. For Against Abstain Nominees 1A Henri Steinmetz ☐ ☐ ☐ 01 Mark Tomkins 02 Sandra Beach Lin NOTE:Such other business as may properly come before the meeting or any adjournment thereof. Table of Contents Please sign exactly as your name(s) appear(s) hereon. When signing as attorney, executor, administrator, or other fiduciary, please give full title as such. Joint owners should each sign personally. All holders must sign. If a corporation or partnership, please sign in fullf ull corporate or partnership name, by authorized officer. Signature [PLEASE SIGN WITHIN BOX] Date Signature (Joint Owners) Date 0000430953_1 R1.0.1.18 0000346557_1 R1.0.1.17 Table of Contents Important Notice Regarding the Availability of Proxy Materials for the Special General Meeting: The Proxy Statement is available at www.proxyvote.com TRINSEO S.A. Special General Meeting of Shareholders November 20, 2019 11:00 AM CET This proxy is solicited by the Board of Directors The shareholder(s) hereby appoint(s) Frank A. Bozich and Angelo N. Chaclas, or either of them, as proxies, each with the power to appoint (his/her) substitute, and hereby authorizes them to represent and to vote, as designated on the reverse side of this ballot, all of the ordinary shares of TRINSEO S.A. that the shareholder(s) is/are entitled to vote at the Special General Meeting of shareholder(s) to be held at 11:00 AM, CET on 11/20/2019, at the the Sofitel Luxembourg Europe, 4, rue du Fort Niedergrünewald, BP 512 / Quartier Européen Nord, L 2015 Luxembourg, Grand Duchy of Luxembourg and any adjournment or postponement thereof. This proxy, when properly executed, will be voted in the manner directed herein. If no such direction is made, this proxy will be voted in accordance with the Board of Directors' recommendations. 0000430953_2 R1.0.1.18     Important Notice Regarding the Availability Table of Proxy Materials for the Special Meeting:The Notice & Proxy Statement is/are available atwww.proxyvote.com.Contents — — — — — — — — — — — — —  — — — — — — — — — — — — — — — — — — — —  — — — — — — — — — —    Continued and to be signed on reverse side TRINSEO S.A. Extraordinary General Meeting of Shareholders November 28, 2017 5:20 p.m. CEST This proxy is solicited by the Board of Directors The shareholder(s) hereby appoint(s) Christopher D. Pappas, Angelo N. Chaclas, and Suzanne Kersten, or any of them, as proxies, each with the power to appoint his or her substitute, and hereby authorize(s) them to represent and to vote, as designated on the reverse side of this ballot, all of the ordinary shares of TRINSEO S.A. that the shareholder(s) is/are entitled to vote at the Extraordinary General Meeting of Shareholders to be held at 5:20 p.m. CEST, on November 28, 2017, at 4 rue du Fort Niedergrünewald, BP 512/Quartier Européen Nord, L-2015 Luxembourg, Grand Duchy of Luxembourg, and any adjournment or postponement thereof. This proxy, when properly executed, will be voted in the manner directed herein. If no such direction is made, this proxy will be voted in accordance with the Board of Directors’ recommendations. Continued and to be signed on reverse side 0000346557_2 R1.0.1.17