CLEAN HARBORS INC

The Company has a Board approved share repurchase plan which authorizes the Company to purchase the Company's common stock on the open market or in privately negotiated transactions periodically in a manner that complies with applicable U.S. securities laws. As of December 31, 2025, the Company’s limit on that repurchase plan was $1.1 billion. On February 18, 2026, the Company’s Board of Directors authorized a $350 million expansion of the Company’s share repurchase program. The number of shares purchased and the timing of the purchases have depended and will depend on a number of factors including share price, cash required for future business plans, trading volume and other conditions. The Company has no obligation to repurchase stock under this program and may suspend or terminate the repurchase program at any time.

During the years ended December 31, 2025, 2024 and 2023, the Company repurchased and retired a total of 1.1 million,0.2 million and 0.3 million shares, respectively, of the Company's common stock for total costs of $249.8 million, $55.0 million and $51.2 million, respectively.

As of December 31, 2025, an additional $249.4 million remained available to repurchase shares under this program.