(b)

David J. Vergo, the President of Safety-Kleen, Inc., a subsidiary of Clean Harbors, Inc. (the “Company”), gave notice on May 3, 2019 of his resignation effective on May 17, 2019. For 2018, Mr. Vergo was a “named executive officer” of the Company as reported in the Company’s proxy statement dated April 24, 2019. The Company thanks Mr. Vergo for his contributions to the Company and wishes him well with his future endeavors.

About CLEAN HARBORS, INC. (NYSE:CLH)

Clean Harbors, Inc. is a provider of environmental, energy and industrial services. The Company operates in six segments: Technical Services; Industrial and Field Services; Kleen Performance Products; SK Environmental Services; Lodging Services, and Oil and Gas Field Services. Its Technical Services segment involves the collection, transportation, treatment and disposal of hazardous and non-hazardous wastes. Its Industrial services segment offers industrial maintenance services and industrial services. Its Kleen Performance Products segment processes used oil to convert into a range of products. SK Environmental Services segment offers environmental services and complementary products. Lodging Services consists of four lines of businesses: Lodge Operations, Mobile Camp Operations, Hospitality Operations and Manufacturing. Oil and Gas Field Services segment provides fluid handling, fluid hauling, production servicing, surface rentals, seismic services and directional boring services.