Exhibit 99.1 Certification Pursuant to 18 U.S.C. (S) 1350, the undersigned officer of Mine Safety Appliances Company (the "Company"), hereby certifies, to the best of his knowledge, that the Company's Quarterly Report on Form 10-Q for the quarter ended September 30, 2002 (the "Report") fully complies with the requirements of Section 13 (a) or 15 (d), as applicable, of the Securities Exchange Act of 1934 and that the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company. Dated: November 8, 2002 /s/ John T. Ryan III Name: John T. Ryan III Title: Chief Executive Officer This certification is furnished solely pursuant to 18 U.S.C. (S) 1350 and is not being filed as part of the Report or as a separate disclosure document.