Clean Harbors Formally Releases PFAS Disposal and Treatment Guidance Standards to Assist Customers and Communities with Decision Making

• Approach Leverages Multiple Technologies Including High-Temperature RCRA-Permitted Incineration, Engineered Landfill Containment and Water Treatment Systems
• Cost-Effective Framework Based on How to Best Address PFAS Contamination
• Standards Align Efficient Treatment Technologies to Concentration Levels and Physical Form of PFAS Compounds
• Guidance Framework Previously Shared with the EPA and the U.S. Senate Committee on Environment and Public Works

Clean Harbors, Inc. ("Clean Harbors" or the "Company") (NYSE:CLH), the leading provider of environmental and industrial services throughout North America, today formally released its disposal and treatment guidance standards for PFAS (per- and poly-fluorinated alkyl substances), the "forever chemicals" that pose significant human health risks. The Company's recommended framework of disposal and treatment options is designed to help decision-makers at organizations most effectively address PFAS based on concentration levels, waste forms and regulatory requirements.

"We have had many customers, governmental agencies and community leaders approach us for advice on how to best move forward with cost-effectively addressing the safe treatment and disposal of PFAS, as well as cleaning up contaminated sites," said Eric Gerstenberg, Co-Chief Executive Officer. "At times, these customers are dealing with an emergency involving PFAS, such as an industrial fire. As of yet, there is no well-established comprehensive framework. We have developed our framework as a potential cost-effective roadmap to assist companies and communities looking to address PFAS site contamination, as well as eliminate existing inventories of PFAS-related products such as AFFF firefighting foam. Our recommendations are based on years of institutional knowledge that stems from assisting customers with efficient solutions for these forever chemicals in its many forms, including AFFF, industrial waters, impacted drinking water and soil. In addition, our framework is based on strong scientific data, including the PFAS incineration study we completed in conjunction with the EPA and the Pentagon in late 2024." The results of the Company's successful PFAS incineration study with the EPA can be found here.

Mike Battles, Co-Chief Executive Officer, said, "PFAS should not be viewed as a one-size-fits-all issue, but rather as a concentration-based framework that matches the waste with the right treatment or disposal pathway. We took a tiered approach in our recommendations, which mirrors the way environmental regulators and remediation practitioners typically address complex contaminants – using a combination of destruction, containment and treatment technologies. As PFAS remediation accelerates nationwide, our integrated framework provides a practical and scalable model for industry and government partners."

"We know that many customers – both private and public – want safe, assured destruction of PFAS at scale to eliminate any further liabilities as these chemicals never degrade and often migrate," said Gerstenberg. "There are many locations that have soil, water or both contaminated by PFAS, as well as stockpiles of AFFF to address. In addition, over the decades, PFAS chemicals have leached into groundwater and contaminated many drinking supplies. Given that customers are facing PFAS in multiple forms, we introduced our ‘Total PFAS Solution' back in 2024 consisting of eight core elements and providing customers with a range of services to meet all their needs, from analysis to water filtration to remediation to disposal. Today, we believe that Clean Harbors remains the only company that can cost effectively offer an end-to-end, single-source answer for any PFAS need, and at a commercially scalable level."

"We have shared our disposal framework with the EPA, and it was also submitted as part of Eric Gerstenberg's written testimony to the Senate EPW Committee in November 2025. Regulators, politicians and PFAS experts alike are increasingly recognizing that no single technology can address all PFAS waste streams. As a result, we developed our comprehensive framework incorporating multiple solutions as a baseline to help customers navigate the risks and challenges presented by these harmful forever chemicals," Battles concluded.

Clean Harbors' Total PFAS Solution offering and PFAS Management Framework are detailed on its PFAS website – www.cleanharbors.com/PFAS.

About Clean Harbors

Clean Harbors (NYSE:CLH) is North America's leading provider of environmental and industrial services. The Company serves a diverse customer base, including a majority of Fortune 500 companies. Its customer base spans a number of industries, including chemical, manufacturing and refining, as well as numerous government agencies. These customers rely on Clean Harbors to deliver a broad range of services such as end-to-end hazardous waste management, emergency spill response, industrial cleaning and maintenance, and recycling services. Through its Safety-Kleen subsidiary, Clean Harbors also is a leading provider of parts washers and environmental services to commercial, industrial and automotive customers, as well as North America's largest re-refiner and recycler of used oil. Founded in 1980 and based in Massachusetts, Clean Harbors operates in the United States, Canada, Mexico, Puerto Rico and India. For more information, visit www.cleanharbors.com.

Safe Harbor Statement

Any statements contained herein that are not historical facts are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements are generally identifiable by use of the words "believes," "expects," "intends," "anticipates," "plans to," "seeks," "will," "should," "estimates," "projects," "may," "likely," "potential," "outlook" or similar expressions. Such statements may include, but are not limited to, statements about the Company's PFAS service offerings, future financial and operating results, plans, strategy, objectives and goals, cost management initiatives, pricing and productivity initiatives, contingent liabilities, liquidity, business, economic and market conditions, trends, customer demand, impacts of tariffs and new legislation, acquisitions, growth opportunities, expectations, challenges and other statements that are not historical facts. Such statements are based upon the beliefs and expectations of Clean Harbors' management as of the date of this press release only and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, without limitation: operational and safety risks; risks relating to the failure of new or existing technologies; cybersecurity risks; the occurrence of natural disasters or other catastrophic events, as well as their residual macroeconomic effects; risks associated with retaining and hiring key personnel; environmental liability and product liability risks relating to hazardous waste management and other components of the Company's business; negative economic, industry or other developments, including market volatility or economic downturns; risks associated with management's assumptions relating to expansion of the Company's landfills; reductions in the demand for emergency response services at industrial facilities or on roadways, railways or waterways, and other remedial projects and regulatory developments; reductions in the demand for oil products and automotive services and volatility in oil prices in the markets the Company serves; changes in statutory and regulatory requirements and risks relating to extensive environmental laws and regulations; risks associated with existing and potential litigation; risks associated with the Company's identification and execution of strategic capital expenditures, acquisitions and divestitures and their related liabilities; risks relating to the availability and sufficiency of the Company's insurance coverage, self-insurance, surety bonds, letters of credit and other forms of financial assurance; the impact of new tax legislation or changes in tax regulations and interpretations; the imposition of trade sanctions or tariffs; fluctuations in interest rates and foreign currency exchange rates; risks relating to the Company's indebtedness and covenants in its debt agreements; risks associated with certain anti-takeover provisions under the Massachusetts Business Corporation Act and the Company's By-Laws, and those items identified as "Risk Factors" in Clean Harbors' most recently filed reports on Form 10-K and Form 10-Q. Forward-looking statements are neither historical facts nor assurances of future performance. Therefore, readers are cautioned not to place undue reliance on these forward-looking statements. Clean Harbors undertakes no obligation to revise or publicly release the results of any revision to these forward-looking statements other than through its filings with the Securities and Exchange Commission, which may be viewed in the "Investors" section of Clean Harbors' website at www.cleanharbors.com.

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Eric J. Dugas

EVP and Chief Financial Officer

Clean Harbors, Inc.

781.792.5100

InvestorRelations@cleanharbors.com



Jim Buckley

SVP Investor Relations

Clean Harbors, Inc.

781.792.5100

Buckley.James@cleanharbors.com



Customer Contact:

Paul Bratti

Senior Vice President, Remediation

Clean Harbors, Inc.

781.792.5000

brattip@cleanharbors.com