What Clean Harbors, Inc. told the SEC could break it.

Clean Harbors' operations are subject to extensive US and Canadian federal/state/provincial environmental regulation (EPA, RCRA-equivalent state programs, OSHA, Coast Guard); non-compliance could impair its ability to collect, process and dispose of hazardous waste, and it carries material landfill final-closure/post-closure liabilities ($59.8M at YE2025).

“Our operations and those of others in the environmental services industry are subject to extensive federal, state, provincial and local environmental requirements in both the United States and Canada... If we fail to comply with regulations governing the transport, handling and disposal of hazardous materials, such failure could negatively impact our ability to collect, process and ultimately dispose of hazardous waste generated by our customers.”

Clean Harbors' Safety-Kleen Sustainability Solutions segment depends on volatile oil-related product pricing — SKSS direct revenue fell $47.4M in 2025 on lower base-oil/blended-oil market pricing — and the premium it can charge for used-oil collection is driven by the overall market price of oil and used-oil-burning regulations.

“Overall product pricing as well as revenues generated and/or costs incurred in connection with the collection of used oil and other raw materials associated with the segment's oil related products can also be volatile and can be impacted by global events and their relative impact on commodity products and pricing. The overall market price of oil and regulations, which change the possible usage of used oil or burning of used oil as a fuel, impact the premium the segment can charge for used oil collections.”

Although no single customer is concentrated, Clean Harbors' revenue tracks the cyclicality of a few large industrial end markets — its top ten industries were ~80% of 2025 revenue, led by general manufacturing (14%), chemical (14%), refineries (12%) and automotive (10%) — so an industrial downturn would pressure waste volumes.

“As a percentage of our 2025 revenues, the top ten industries we serviced totaled approximately 80% of revenues and included general manufacturing (14%), chemical (14%), refineries (12%), automotive (10%), utilities (7%), transportation (6%), government (5%), base and blended oils (4%), oil and gas (4%) and retail (4%).”