Koppers (KOP) 8-K Changes in Registrant's Certifying Accountant

Exhibit 16.1

March 29, 2016

Securities and Exchange Commission

100 F Street, N.E.

Washington, DC 20549

Ladies and Gentlemen:

We have read Item 4.01 of Form 8-K dated March 29, 2016, of Koppers Holdings Inc. and are in agreement with the statements contained in paragraphs 2, 3 and 4 of Item 4.01(a). We have no basis to agree or disagree with other statements of the registrant contained therein.

/s/ Ernst & Young LLP