Clean Harbors Promotes Eugene Cookson to President of New Business Unit.

Business Editors/Environment Writers

BRAINTREE, Mass.--(BUSINESS WIRE)--March 3, 2003

Clean Harbors, Inc. (Nasdaq: CLHB), the leading provider of hazardous waste and environmental management services throughout North America, today announced the appointment of Eugene A. Cookson as president of the Company's recently created Site Services Group. In his new role, Cookson, 45, will be responsible for growing Clean Harbors' field service and industrial services capabilities across North America.

"Gene Cookson is a 12-year veteran of Clean Harbors who has demonstrated the leadership and skills to take our Site Services Group to the next level of operational performance, growth and profitability," said Alan S. McKim, Clean Harbors' chairman and chief executive officer. "With the recent acquisition and integration of Safety-Kleen Corp.'s Chemical Services Division, we now have a major opportunity to cross-sell our unique field services capabilities to thousands of new customers, and to leverage our personnel, plants and equipment across the entire network of our newly-combined North American operations."

Cookson joined Clean Harbors in 1991 and worked his way up through the ranks to become Senior Vice President, Field Services and then Chief Operating Officer of Clean Harbors Environmental Services, Inc. Mr. Cookson received a Master's Degree in Civil Environmental Engineering from Northeastern University in Boston.

"The current Site Services business has approximately 800 employees and does approximately $175 million in sales on a combined annualized basis," Cookson said. "The business operates in a highly fragmented industry with an estimated market value of $15 billion and a 5 to 7 percent annual growth rate. We have the experience and resources to grow field services in the new geographic areas where the company now has disposal capabilities, including the Gulf Coast, Southwest, West Coast and several Canadian Provinces."

"In industrial services, our primary focus will be on expanding our relationship with existing clients in the utility, petrochemical, major oil and refining industries, and the pulp and paper market," said Cookson. "Our growth strategy will include a combination of acquisitions and organic growth replicating the very successful, low-cost growth model we employed to build Clean Harbors into the dominant environmental site services provider on the East Coast."

The Site Services Group is composed of two primary service lines in field service and industrial service. Field service operations encompass short duration on-site environmental projects such as decontamination, confined-space hazardous environments, large project remediation and emergency response. Industrial service operations consist of planned shutdown work where time-sensitive industrial cleaning and water blasting is required. The Company has been the lead clean-up contractor for most major chemical and oil spills on the East Coast, and for emergency response activities such as the World Trade Center disaster and anthrax contaminations in New York locations.

About Clean Harbors, Inc.

Clean Harbors, Inc. through its subsidiaries provides a wide range of environmental and waste management services to a diversified customer base including a majority of the Fortune 500 companies, thousands of smaller private entities and numerous governmental agencies. Within its international footprint, Clean Harbors has service and sales offices located in 40 states, six Canadian provinces, Mexico, and Puerto Rico, and operates over 50 waste management facilities strategically located throughout North America. For more information, visit our Website at www.cleanharbors.com.

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