CLH: Financial results · Company disclosure

Item 2.02 Results of Operations and Financial Condition On October 28, 2026, Clean Harbors, Inc. (the “Company”) issued a press release announcing the Company’s results of operations for the third quarter ended September 30, 2026. A copy of that press release is furnished with this report as Exhibit 99.1. Item 7.01 Regulation FD Disclosure On October 28, 2026, the Company issued a press release announcing an executive leadership transition. A copy of the press release is furnished as Exhibit 99.2. Item 9.01 Financial Statements and Exhibits (d) Exhibits. The following exhibits are being furnished herewith: Exhibit No. Description 99.1 Press Release of the Company dated October 28, 2026 Announcing Results of Operations for the third quarter ended September 30, 2026 99.2 Press Release of the Company dated October 28, 2026 Announcing Executive Leadership Transition 104 The cover page from this Current Report on Form 8-K, formatted in iXBRL (Inline eXtensible Business Reporting Language) 1 SIGNATURES Pursuant to the requirements of the Securities and Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. Clean Harbors, Inc. (Registrant) October 28, 2026 /s/ Eric J. Dugas Executive Vice President and Chief Financial Officer 2