Results of Operations and Financial Condition On July 30, 2026 , the Company issued a press release announcing its financial results for the quarter ended June 30, 2026. A copy of the press release is furnished herewith as Exhibit 99.1 to this report.

Director — Octavio Marquez: Election of a new director to the Board of Directors.

Other Events On July 9, 2026, MSA Safety Incorporated issued a press release announcing that it has completed the acquisition of Autronica Fire and Security and its affiliated companies. The full text of the press release is attached hereto as Exhibit 99.1 and incorporated herein by reference.

Entry Into a Material Definitive Agreement Acquisition of Autronica Buyer Norway AS and its Affiliated Companies On May 5, 2026, MSA Safety Incorporated (“ MSA ”) and Aegir Safety Holdings AS (“ Safety Holdings ”), an indirect wholly owned subsidiary of MSA, entered into an agreement to acquire Autronica Buyer Norway AS and its affiliated companies (referred to herein collectively as “ Autronica ”). Pursuant to a Sale and Purchase Agreement (the “ SPA ”), by and among MSA, Safety Holdings, Au…

Results of Operations and Financial Condition On May 4, 2026 , the Company issued a press release announcing its financial results for the quarter ended March 31, 2026. A copy of the press release is furnished herewith as Exhibit 99.1 to this report.

Other Events On February 20, 2026, the Board of Directors (the “Board”) of MSA Safety Incorporated (the “Company”) approved a new stock repurchase program to replace the Company’s existing program. The Board did not set a termination date for the new program. The new program authorizes up to $500 million in repurchases of Company common stock. The timing, manner, price and amount of any repurchases under the program will be determined by the Company in its discretion. Acquisitions pursuant to…

Results of Operations and Financial Condition On February 11, 2026, the Company issued a press release announcing its financial results for the quarter and full year ended December 31, 2025. A copy of the press release is furnished herewith as Exhibit 99.1 to this report.

Senior Vice President and President of MSA International — David J. Howells: The departure is a planned retirement with a defined internal succession plan where duties are redistributed to existing senior personnel rather than a sudden loss of leadership.

Results of Operations and Financial Condition On October 28, 2025 , the Company issued a press release announcing its financial results for the quarter ended September 30, 2025. A copy of the press release is furnished herewith as Exhibit 99.1 to this report.

CFO — Julie A. Beck: The filing announces the appointment of an external candidate as CFO, replacing an interim officer, which is a standard succession event rather than a sudden loss of a sitting executive.

Results of Operations and Financial Condition On August 4, 2025 , the Company issued a press release announcing its financial results for the quarter ended June 30, 2025. A copy of the press release is furnished herewith as Exhibit 99.1 to this report.

Other Events On May 6, 2025, MSA Europe Holdings GmbH, a wholly owned indirect subsidiary of MSA Safety Incorporated (the “Company”), completed the acquisition of M&C TechGroup Germany GmbH, a manufacturer of gas analysis solutions and technologies. A copy of the Company’s press release is furnished herewith as Exhibit 99.1 to this report.

Results of Operations and Financial Condition On April 29, 2025 , the Company issued a press release announcing its financial results for the quarter ended March 31, 2025. A copy of the press release is furnished herewith as Exhibit 99.1 to this report.

Entry into a Material Definitive Agreement Credit Agreement On April 1, 2025, MSA Safety Incorporated (“MSA”), MSA UK Holdings Limited (“MSA UK”) and MSA Great Britain Holdings Limited (“MSA GB”), as borrowers, entered into a Fifth Amended and Restated Credit Agreement dated as of April 1, 2025 (the “Credit Agreement”) with various MSA subsidiaries, as guarantors, various financial institutions, as lenders, and PNC Bank, National Association, as administrative agent. See

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant On April 1, 2025, MSA, MSA UK, and MSA GB, as borrowers, and various MSA subsidiaries, as guarantors, entered into the Credit Agreement. The Credit Agreement amended and restated MSA’s existing Fourth Amended and Restated Credit Agreement dated as of May 24, 2021. Under the Credit Agreement, funds may be borrowed on an unsecured, revolving credit basis in a maximum outstanding amo…

CFO — Lee B. McChesney: The CFO is resigning to pursue another opportunity, which is a genuine departure of a senior executive, though the lack of disagreement and immediate interim appointment mitigate negative sentiment.

Results of Operations and Financial Condition On February 12, 2025, the Company issued a press release announcing its financial results for the quarter and full year ended December 31, 2024. A copy of the press release is furnished herewith as Exhibit 99.1 to this report.

Results of Operations and Financial Condition On October 23, 2024 , the Company issued a press release announcing its financial results for the quarter ended September 30, 2024. A copy of the press release is furnished herewith as Exhibit 99.1 to this report.

Results of Operations and Financial Condition On July 24, 2024 , the Company issued a press release announcing its financial results for the quarter ended June 30, 2024. A copy of the press release is furnished herewith as Exhibit 99.1 to this report.

Other Events. On May 10, 2024, the Board of Directors (the “Board”) of MSA Safety Incorporated (the “Company”) approved a new stock repurchase program to replace the Company’s existing program. The Board did not set a termination date for the new program. The new program authorizes up to $200 million in repurchases of Company common stock. The timing, manner, price and amount of any repurchases under the program will be determined by the Company in its discretion. Acquisitions pursuant to the…

Results of Operations and Financial Condition On April 29, 2024, the Company issued a press release announcing its financial results for the quarter ended March 31, 2024. A copy of the press release is furnished herewith as Exhibit 99.1 to this report.

President — Bob W. Leenen: The filing details the separation terms for a former Senior Vice President and President of a major international division, confirming a genuine executive departure with standard severance and restrictive covenants.