MSA Safety Inc

Important Notice Regarding the Availability of Proxy Materials for the Shareholders Meeting to be held on May 8, 2026

The 2026 Proxy Statement and the Annual Report to Shareholders for the year ended December 31, 2025 are also available at www.proxyvote.com The 2026 Annual Meeting of Shareholders for the year ended December 31, 2025 will convene via webcast at www.virtualshareholdermeeting.com/MSA2026

This Proxy Statement is furnished in connection with the solicitation by the Board of Directors (the “Board”) of MSA Safety Incorporated (the “Company” or “MSA”) of proxies in the accompanying form to be voted at the Annual Meeting of Shareholders of the Company to be held on Friday, May 8, 2026, and at any and all adjournments thereof, for the purposes set forth in the accompanying Notice of Annual Meeting of Shareholders.

Instead of mailing printed proxy materials on March 26, 2026, we mailed a Notice of Internet Availability of Proxy Materials advising shareholders to view our Proxy Statement, Proxy Card and 2025 Annual Report free of charge online at www.proxyvote.com, or to request paper or email copies. Only shareholders who have requested printed materials will receive them. We encourage all shareholders to access the Company’s proxy materials online to reduce the environmental impact and costs associated with paper copies. To vote your proxy by mail, mark your vote on the proxy card, and follow the mailing directions on the card. To vote your proxy by telephone or electronically using a smartphone, tablet or the internet, follow the instructions on the proxy card. If you received a notice of internet availability of proxy materials, you may vote by following the instructions contained in the notice. The proxy holders will vote your shares according to your directions. If you sign and return your proxy card but do not mark any selections, your shares represented by that proxy will be voted as recommended by the Board.

We encourage you to vote by proxy as soon as possible. A shareholder giving the accompanying proxy by mail has the power to revoke or change it at any time prior to its exercise upon written notice given to the Secretary of the Company. Please note that, in order to be effective, the revocation or change must be received by the Company by 11:59 p.m. Eastern Time on May 7, 2026. The mailing address of the principal executive offices of the Company is 1000 Cranberry Woods Drive, Cranberry Township, PA 16066. A shareholder voting the proxy by telephone or internet has the power to revoke or change such proxy vote by voting again and following the instructions and meeting the deadlines for such vote as set forth on the proxy card.