Clean Harbors Prices Offering of Senior Notes Due 2034

Clean Harbors, Inc. (“Clean Harbors” or the “Company”) (NYSE: CLH), announced today that it has priced a private offering of $600 million of senior notes due 2034 (the “notes”).

The notes, which carry an interest rate of 6.250%, were priced for purposes of resale at 100.000% of their aggregate principal amount. The issuance and sale of the notes is expected to close on or about October 1, 2026, subject to customary closing conditions. The Company intends to use the net proceeds from the offering of notes to finance the purchase price of the Company’s previously announced acquisition of EnviroServe, a national provider of environmental and waste management services (the “EnviroServe Acquisition”), and the remainder of the net proceeds to repay the borrowings under its revolving credit facility that were incurred to partially finance the purchase price of the Company’s previously announced acquisition of ES&H (the “ES&H Acquisition” and, together with the EnviroServe Acquisition, the “Acquisitions”). There can be no assurance that the Acquisitions will be completed on the terms the Company anticipates, in a timely manner or at all. The consummation of the offering of notes is not contingent on the completion of the Acquisitions and, if either Acquisition is not completed, the Company intends to use the remaining net proceeds for general corporate purposes.