Here are 1-2 brief analogies for Clean Harbors (CLH):

• Waste Management for hazardous waste and industrial services.
• Halliburton for environmental cleanup and industrial solutions.

• Hazardous Waste Management: Provides comprehensive services for the collection, transportation, treatment, recycling, and disposal of hazardous and non-hazardous waste materials.
• Environmental Field Services: Offers on-site environmental solutions including emergency response, site remediation, and industrial cleaning and maintenance for various industries.
• Safety-Kleen Oil Re-refining: Collects used lubricating oils and re-refines them into high-quality new base and finished lubricating oils.
• Safety-Kleen Parts Cleaning: Supplies specialized equipment and solvents for parts cleaning, along with associated waste management and recycling services.

Clean Harbors (CLH) Major Customers

Clean Harbors (CLH) primarily sells its environmental, energy, and industrial services to other companies and governmental agencies, making it a business-to-business (B2B) service provider. It does not sell primarily to individuals.

Due to the diverse nature of its client base, which spans a majority of Fortune 500 companies, thousands of smaller private entities, and numerous federal, state, and local governmental agencies, specific individual "major customers" (i.e., named companies that account for a significant portion of CLH's total revenue, typically 10% or more) are generally not disclosed in public filings. Clean Harbors' revenue is diversified across a broad spectrum of clients.

Therefore, its "major customers" can be best described by the industries and types of organizations it serves:

• Manufacturing Companies: These include businesses in various sectors such as automotive, chemicals, pharmaceuticals, consumer goods, and heavy industry. They rely on Clean Harbors for waste management, facility decommissioning, industrial cleaning, and environmental compliance services.
• Energy Sector Companies: This category encompasses companies involved in oil and gas exploration, production, refining, and power generation. Clean Harbors provides services like oilfield services, waste processing, emergency response, and facility maintenance.
• Chemical Companies: A significant portion of Clean Harbors' business involves handling and disposing of hazardous waste, making chemical manufacturers key customers for specialized hazardous waste management, transportation, and disposal services.
• Healthcare Facilities: Hospitals, laboratories, and other healthcare providers utilize Clean Harbors for the safe disposal of medical, pharmaceutical, and other regulated waste.
• Government Agencies: Federal, state, and local governmental bodies contract Clean Harbors for environmental cleanups, waste management, emergency response services, and infrastructure maintenance.
• Utilities: Including water, electric, and gas utilities, which require services for waste management, environmental compliance, and infrastructure-related industrial services.
• Retail and Commercial Businesses: Various large-scale retail chains and commercial enterprises engage Clean Harbors for waste management solutions, industrial services, and environmental support.

These categories encompass a vast number of public and private companies, including many Fortune 500 entities, which rely on Clean Harbors for critical environmental and industrial services. Since specific public companies are not individually named as major customers by CLH due to the diversification of its client base, we cannot list their symbols.

Michael L. Battles, Co-Chief Executive Officer

Mr. Battles was appointed Co-Chief Executive Officer and Co-President of Clean Harbors in March 2023. Prior to this, he served for seven years as the Company's Executive Vice President and Chief Financial Officer. He joined Clean Harbors in September 2013 as Senior Vice President, Corporate Controller and Chief Accounting Officer. Before joining Clean Harbors, Mr. Battles held various senior financial positions at PerkinElmer Inc., a global leader in human and environmental health, including financial leadership of its Human Health business, Chief Accounting Officer, and acting Chief Financial Officer. Earlier in his career, he worked for Deloitte & Touche LLP in the firm's audit function. Mr. Battles is also a member of the board of directors of Casella Waste Systems, Inc.

Eric W. Gerstenberg, Co-Chief Executive Officer

Mr. Gerstenberg was named Co-Chief Executive Officer and Co-President of Clean Harbors in March 2023, after serving for eight years as the Company's Chief Operating Officer. He joined Clean Harbors in 1989 and has held a variety of positions of increasing responsibility, including President of the Environmental, Industrial & Field Services business, Vice President of Disposal Services, and Executive Vice President, Environmental Services. He briefly served as Vice President of Operations for privately owned Pollution Control Industries from 1997 to 1999 before returning to Clean Harbors.

Eric J. Dugas, Executive Vice President and Chief Financial Officer

Mr. Dugas was appointed Executive Vice President and Chief Financial Officer of Clean Harbors in March 2023. He previously served for five years as Senior Vice President, Finance and Chief Accounting Officer. Mr. Dugas joined Clean Harbors in March 2014 as the Director of External Reporting and Technical Accounting. Before joining Clean Harbors, he spent 13 years with Deloitte & Touche LLP, holding several positions of increasing management responsibility.

Alan S. McKim, Founder, Executive Chairman and Chief Technology Officer

Mr. McKim founded Clean Harbors in 1980. He became Executive Chairman and Chief Technology Officer of the Company in March 2023 as part of a planned transition. Prior to this, he served as Chairman of the Board of Directors and Chief Executive Officer of the Company since its inception. Mr. McKim is recognized as an industry leader with over four decades in the environmental services business.

Brian P. Weber, Executive Vice President and President of Safety-Kleen Sustainability Solutions

Mr. Weber was named Executive Vice President and President of Safety-Kleen Sustainability Solutions in March 2023. Before this role, he served as the Company's Executive Vice President, Corporate Planning and Development. Mr. Weber joined Clean Harbors in 1990 and has held a variety of senior management positions, including Senior Vice President of Transportation, Vice President of CleanPack Services, and Vice President, Technical Services.

The rapid development and scaling of advanced chemical recycling and waste-to-energy technologies, particularly for difficult-to-treat hazardous waste streams and mixed industrial plastics, pose a clear emerging threat. These technologies aim to convert waste into valuable products or energy, thereby diverting significant volumes away from traditional incineration and hazardous waste landfills—core disposal services for Clean Harbors. As these technologies mature and become more economically viable and widely adopted, they could directly reduce the demand for Clean Harbors' established disposal infrastructure and services.

Addressable Markets for Main Products or Services:

Clean Harbors (CLH) is expected to drive future revenue growth over the next two to three years through several key initiatives and market trends:

1. Expansion in Environmental Services and Incineration Capacity: The Environmental Services segment, which constitutes approximately 84% of total revenue, is a primary growth engine. This growth is anticipated from continued strong demand for waste collection, disposal services, and remediation projects. A significant contributor is the ramp-up of facilities like the Kimball incinerator, which began processing hazardous waste in December and is expected to optimize volumes and mix over the next 12-18 months, adding meaningful capacity and driving margin expansion.
2. Growth in PFAS Remediation Market: The escalating regulatory landscape and increasing urgency surrounding the management and destruction of per- and polyfluoroalkyl substances (PFAS) present a substantial market opportunity. Clean Harbors is uniquely positioned with end-to-end PFAS destruction capabilities, allowing it to capture significant long-term revenue as new governmental and corporate standards are implemented.
3. Strategic Pricing and Operational Efficiency: The company's ability to implement pricing improvements across its services and maintain disciplined operational efficiency is a consistent driver of revenue and margin expansion. This includes greater overall volumes within its disposal and recycling assets, strong labor management, and efficient utilization of its facilities, such as high incinerator utilization rates.
4. Benefits from Reshoring and Industrial Investments: The ongoing trend of reshoring manufacturing and substantial planned industrial investments within the United States are projected to create increased demand for Clean Harbors' industrial services. Customers expanding production and breaking ground on new facilities contribute to a robust pipeline for the company's offerings.
5. Strategic Acquisitions and Technology Investments: Recent acquisitions, such as HEPACO (acquired in 2024) and Noble Oil, have contributed to revenue growth and expanded the company's technical capabilities. Clean Harbors also continues to make strategic capital investments, including the new Solvent De-Asphalting (SDA) unit, which is expected to enhance the Safety-Kleen Sustainability Solutions segment and generate incremental EBITDA upon its commercialization.

Share Repurchases

• Clean Harbors authorized a $500 million expansion of its existing share repurchase program in December 2023. As of December 1, 2023, approximately $54 million remained from the previous program.
• As of December 7, 2023, the company had repurchased approximately 8.5 million shares at an average price of about $64 per share under its original $600 million stock repurchase plan.
• The company conducted $50 million in share repurchases during Q3 2025.

Share Issuance

• No significant share issuances by the company have been identified within the last 3-5 years.

Inbound Investments

• No significant inbound investments by third-parties in Clean Harbors have been identified within the last 3-5 years.

Outbound Investments

• Clean Harbors acquired HEPACO, an environmental services provider, for $400 million in cash. The acquisition was announced in February 2024 and completed in March 2024.
• In August 2021, Clean Harbors acquired HydroChemPSC for $1.25 billion.

Capital Expenditures

• Clean Harbors anticipates spending between $345 million and $375 million in capital expenditures in 2025, excluding approximately $15 million allocated for the Phoenix hub project.
• Actual capital expenditures were $422.3 million in 2024, $345.1 million in 2023, and $241.9 million in 2022.
• The company announced a $210 million to $220 million investment for the construction of an SDA Unit, an advanced processing plant expected to launch commercially in 2028 and generate annual EBITDA of $30 million to $40 million.