CERTIFICATION UNDER SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002
Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (18 U.S.C. Section 1350), the undersigned certifies that (1) this Quarterly Report of W. R. Grace & Co. (the "Company") on Form 10-Q for the period ended June 30, 2016, as filed with the Securities and Exchange Commission on the date hereof (this "Report"), fully complies with the requirements of Sections 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended, and (2) the information contained in this Report fairly presents, in all material respects, the financial condition and results of operations of the Company.
/s/ A. E. FESTA
Chairman and Chief Executive Officer
/s/ THOMAS E. BLASER
Senior Vice President and Chief Financial Officer
Date: August 4, 2016
A signed original of this written statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.