EXHIBIT 4.3 WAIVER AND SECOND AMENDMENT TO CREDIT AGREEMENT August 20, 2002 Airgas, Inc. Radnor Court, Suite 100 259 Radnor-Chester Road Radnor, PA 19807 Attn: Chief Financial Officer RE: TENTH AMENDED AND RESTATED CREDIT AGREEMENT DATED AS OF JULY 30, 2001 BY AND AMONG AIRGAS, INC. ("AIRGAS" OR "THE BORROWER"), AIRGAS CANADA, INC., AND RED-D-ARC LIMITED (EACH A "CANADIAN BORROWER" AND TOGETHER WITH AIRGAS, THE "BORROWERS"), THE GUARANTORS FROM TIME TO TIME PARTY THERETO, THE SEVERAL LENDERS FROM TIME TO TIME PARTY THERETO AS U.S. LENDERS (THE "U.S. LENDERS"), THE SEVERAL LENDERS FROM TIME TO TIME PARTY THERETO AS CANADIAN LENDERS (THE "CANADIAN LENDERS"), BANK OF AMERICA, N.A., AS ADMINISTRATIVE AGENT (THE "U.S. AGENT") AND CANADIAN IMPERIAL BANK OF COMMERCE, AS CANADIAN ADMINISTRATIVE AGENT (THE "CANADIAN AGENT"), AS AMENDED FROM TIME TO TIME (THE "CREDIT AGREEMENT") Ladies and Gentlemen: Reference is made to the Credit Agreement described above, the defined terms of which are incorporated herein by reference. WAIVERS At your request, the Required Lenders hereby waive (the "Waiver") the requirement set forth in Section 7.13(a) of the Credit Agreement that the Credit Parties deliver to the Collateral Agent legal opinions of foreign counsel for Airgas S.A. de C.V. and Airgas International, Inc. with respect to the pledge of the Capital Stock of such Subsidiaries to secure the Credit Party Obligations. The Waiver shall be effective only in the specific circumstances provided for above and only for the purposes for which given. AMENDMENTS The parties hereto hereby agree to amend the definition of "U.S. Issuing Lender" set forth in Section 1.1 of the Credit Agreement in its entirety to read as follows: "U.S. Issuing Lender" means, with respect to a particular U.S. Letter of Credit, (i) Bank of America, in its capacity as issuer of such U.S. Letter of Credit or (ii) such other U.S. Lender selected by the Borrower (upon notice to the U.S. Agent) from time to time to issue such U.S. Letter of Credit. August 20, 2002 Page 2 The parties hereto hereby agree that a new Section 2.3(l) is hereby added to the Credit Agreement to read as follows: (l) Role of U.S. Agent. Airgas and each U.S. Issuing Lender agree to provide the U.S. Agent with a copy of any notice or report otherwise required to be furnished by such Person to any other Person pursuant to Sections 2.3(a), 2.3(b) or 2.3(d). Furthermore, all payments required to be made by any U.S. Lender to a U.S. Issuing Lender pursuant to Section 2.3 shall be made to the U.S. Agent, for the account of such U.S. Issuing Lender, and the U.S. Agent shall distribute such payments to such U.S. Issuing Lender. Except as modified hereby, all of the terms and provisions of the Credit Agreement and the other Credit Documents shall remain in full force and effect. This letter agreement may be executed in one or more counterparts, each of which constitute an original, and all of which taken together shall constitute a single document. This letter agreement shall be effective as of the date hereof upon execution by the Credit Parties and the Required Lenders. This letter agreement shall be governed by and construed in accordance with the laws of the State of New York. Sincerely, BANK OF AMERICA, N.A., as U.S. Agent By: /s/Donald J. Chin ---------------------------------- Name: Donald J. Chin Title: Managing Director [The remainder of this page has been left blank intentionally.] ACCEPTED AND AGREED: AIRGAS, INC. By: /s/Joseph C. Sullivan ---------------------- Name: Joseph C. Sullivan Title: Vice President and Treasurer AIRGAS CANADA INC. By: /s/Robert M. McLaughlin ------------------------------- Name: Robert M. McLaughlin Title: Vice President RED-D-ARC LIMITED By: /s/Robert M. McLaughlin ------------------------------- Name: Robert M. McLaughlin Title: Vice President U.S. GUARANTORS: AIRGAS-EAST, INC. AIRGAS-GREAT LAKES, INC. AIRGAS-MID AMERICA, INC. AIRGAS-NORTH CENTRAL, INC. AIRGAS-SOUTH, INC. AIRGAS-GULF STATES, INC. AIRGAS-INTERMOUNTAIN, INC. AIRGAS-MID SOUTH, INC. AIRGAS-NORPAC, INC. AIRGAS-NORTHERN CALIFORNIA & NEVADA, INC. AIRGAS-SOUTHWEST, INC. AIRGAS-WEST, INC. AIRGAS-SAFETY, INC. RUTLAND TOOL & SUPPLY CO., INC. AIRGAS CARBONIC, INC. AIRGAS SPECIALTY GASES, INC. NITROUS OXIDE CORP. PURITAN MEDICAL PRODUCTS, INC. RED-D-ARC, INC. AIRGAS REALTY, INC. AIRGAS DATA, LLC By: /s/Robert M. McLaughlin ------------------------------- Name: Robert M. McLaughlin Title: Vice President ATNL, INC. By: /s/Connie S. Linhart ---------------------- Name: Connie S. Linhart Title: President and Treasurer CANADIAN SUBSIDIARY GUARANTORS: AIRGAS INTERNATIONAL, INC. AIRGAS, S.A. DE C.V. By: /s/Joseph C. Sullivan ---------------------- Name: Joseph C. Sullivan Title: Vice President [Signatures continued] U.S. LENDERS: BANK OF AMERICA, N.A. By: /s/Donald J. Chin ------------------------------------- Name: Donald J. Chin Title: Managing director BANCA NAZIONALE DEL LAVARO S.P.A NEW YORK BRANCH By: /s/Frederic W. Hall ------------------------------------- Name: Frederic W. Hall Title: Vice President By: /s/Leonardo Valentine ------------------------------------- Name: Leonardo Valentine Title: First Vice President THE BANK OF NEW YORK By: /s/Walter C. Parelli ------------------------------------- Name: Walter C. Parelli Title: Vice President BANK OF TOYKO-MITSUBISHI TRUST COMPANY By: /s/Spencer Hughes ------------------------------------- Name: Spencer Hughes Title: Vice President CIBC INC. By: /s/Dominic Sorresso ------------------------------------- Name: Dominic Sorresso Title: Executive Director JP MORGAN CHASE BANK By: /s/Lee P. Brennan ------------------------------------- Name: Lee P. Brennan Title: Vice President WACHOVIA BANK, NATIONAL ASSOCIATION By: /s/David L. Driggers ---------------------- Name: David L. Driggers Title: Managing Director PNC BANK, NATIONAL ASSOCIATION By: /s/Keith R. White ------------------------------------- Name: Keith R. White Title: Vice President FLEET NATIONAL BANK By: /s/Janet G. O'Donnell ------------------------------------- Name: Janet G. O'Donnell Title: Managing Director MELLON BANK, N.A. By: /s/William M. Feathers ------------------------------------- Name: William M. Feathers Title: Vice President NATIONAL CITY BANK By: /s/Heather M. Gotwols ------------------------------------- Name: Heather M. Gotwols Title: Corporate Banking Officer BANK OF OKLAHOMA, N.A. By: /s/Pamela J. Amburgy ------------------------------------- Name: Pamela J. Amburgy Title: Vice President FARMERS & MERCHANTS BANK OF CENTRAL CALIFORNIA By: /s/Stephen A. Fleming ------------------------------------- Name: Stephen A. Fleming Title: Head of Business Banking, EVP MERRILL LYNCH BUSINESS FINANCIAL SERVICES INC. By: /s/Valerie Wilder Moore ------------------------------------- Name: Valerie Wilder Moore Title: Assistant Vice President AIB DEBT MANAGEMENT LTD. By: /s/John Farrace /s/Rima Terradista --------------- ------------------- Name: John Farrace Rima Terradista Title: SVP SVP ATHENA CDO LIMITED JISSEKIKUN FUNDING, LTD. SAN MIGUEL CDO, LTD. SEQUILS-MAGNUM, LTD. C/O PACIFIC INVESTMENT MANAGEMENT COMPANY LLC By: /s/Mohan V. Phansalkar ----------------------------------------- Name: Mohan V. Phansalkar Title: Executive Vice President HARCH CLO I C/O HARCH CAPITAL MANAGEMENT By: /s/Michael E. Lewitt ----------------------------------------- Name: Michael E. Lewitt Title: Authorized Signatory LAGUNA FUNDING, LLC By: /s/Ann E. Morris ----------------------------------------- Name: Ann E. Morris Title: Assistant Vice President MONUMENT CAPITAL LTD., AS ASSIGNEE By: Alliance Capital Management L.P., as Investment Manager By: Alliance Capital Management Corporation, as General Partner By: /s/Joel Serebransky ----------------------------------------- Name: Joel Serebransky Title: Senior Vice President BANK LEUMI USA By: /s/Joung Hee Hong ----------------------------------------- Name: Joung Hee Hong Title: Vice President OCTAGON INVESTMENT PARTNERS III, LTD. By: /s/Michael B. Nechamkin ----------------------------------------- Name: Michael B. Nechamkin Title: Portfolio Manager CANADIAN AGENT: CANADIAN IMPERIAL BANK OF COMMERCE By: /s/Dominic Sorresso ----------------------- Name: Dominic Sorresso Title: Executive Director CANADIAN LENDERS: CANADIAN IMPERIAL BANK OF COMMERCE By: /s/Dominic Sorresso -------------------------------- Name: Dominic Sorresso Title: Executive Director BANK OF AMERICA CANADA By: /s/Nelson Lam -------------------------------- Name: Nelson Lam Title: Vice President MELLON BANK, N.A. - CANADA BRANCH By: /s/William M. Feathers -------------------------------- Name: William M. Feathers Title: Vice President