Darren R. Scandone Joins Clean Harbors as Chief Human Resources Officer

NORWELL, Mass.--(BUSINESS WIRE)--May 15, 2007--Clean Harbors, Inc. ("Clean Harbors") (NASDAQ: CLHB), the leading provider of environmental and hazardous waste management services throughout North America, today announced that the Company has named Darren R. Scandone, 53, to the new position of Chief Human Resources Officer, effective May 14, 2007. Mr. Scandone will report to Clean Harbors' Chief Executive Officer Alan S. McKim and will be a member of the Company's executive committee. Most recently Scandone served as Managing Director, Global Human Resources of Investment Technology Group (ITG), a specialized agency brokerage and technology firm that partners with clients globally to provide innovative solutions spanning the entire investment process.

"With more than 30 years in human resources and extensive experience with engineering, manufacturing and technology driven organizations, Darren is a seasoned business leader who is well suited for the newly created position of Chief Human Resource Officer," stated Alan S. McKim, Chairman and Chief Executive Officer. "Having recently completed a strategic realignment of the company's personnel, Darren will be a valuable resource for Clean Harbors as we effectively manage our human capital and grow into a billion dollar organization. I am confident that he will help us achieve our goals and support our growth plans for the future."

As the Managing Director, Global Human Resources of ITG, Scandone expanded the team's capability by hiring functional specialists and significantly improved service levels with geographically focused human resources generalists. He also built an integrated staffing function hiring more than 230 people to support ITG's aggressive growth objectives. Prior to ITG, Scandone led human resources for several leading businesses including the Macgregor Group, a premier financial technology provider servicing the global investment community; CVS Corporation, a leading U.S. pharmacy; Oak Industries, a leading manufacturer of electronic parts for the telecommunications industry; and Motorola, Inc. Scandone began his career at Polaroid Holdings Corporation and earned a BS in Economics and Production Management from Boston College. He resides with his family in Duxbury, MA.

About Clean Harbors, Inc.

Clean Harbors, Inc. is North America's leading provider of environmental and hazardous waste management services. With an unmatched infrastructure of 49 waste management facilities, including nine landfills, six incineration locations and six wastewater treatment centers, the Company provides essential services to over 45,000 customers, including more than 325 Fortune 500 companies, thousands of smaller private entities and numerous federal, state and local governmental agencies. Headquartered in Norwell, Massachusetts, Clean Harbors has more than 100 locations strategically positioned throughout North America in 36 U.S. states, six Canadian provinces, Mexico and Puerto Rico. 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, and involve risks and uncertainties. These forward-looking statements are generally identifiable by use of the words "believes," "expects," "intends," "anticipates," "plans to," "estimates," "projects," or similar expressions. These forward-looking statements are subject to certain risks and uncertainties that could cause actual results to differ materially from those reflected in these forward-looking statements. Readers are cautioned not to place undue reliance on these forward-looking statements, which reflect management's opinions only as of the date hereof. The Company undertakes no obligation to revise or publicly release the results of any revision to these forward-looking statements other than through its various filings with the Securities and Exchange Commission. Furthermore, all financial information in this press release is based on preliminary data and is subject to the final closing of the Company's books and records.

A variety of factors beyond the control of the Company may affect the Company's performance, including, but not limited to:

    --  The Company's ability to successfully integrate Teris'
        operations and assets into its existing network of services
        and disposal facilities;

    --  The Company's ability to manage the significant environmental
        liabilities that it assumed in connection with the CSD and
        Teris acquisitions;

    --  The availability and costs of liability insurance and
        financial assurance required by governmental entities relating
        to our facilities;

    --  The effects of general economic conditions in the United
        States, Canada and other territories and countries where the
        Company does business;

    --  The effect of economic forces and competition in specific
        marketplaces where the Company competes;

    --  The possible impact of new regulations or laws pertaining to
        all activities of the Company's operations;

    --  The outcome of litigation or threatened litigation or
        regulatory actions;

    --  The effect of commodity pricing on overall revenues and
        profitability;

    --  Possible fluctuations in quarterly or annual results or
        adverse impacts on the Company's results caused by the
        adoption of new accounting standards or interpretations or
        regulatory rules and regulations;

    --  The effect of weather conditions or other aspects of the
        forces of nature on field or facility operations;

    --  The effects of industry trends in the environmental services
        and waste handling marketplace; and

    --  The effects of conditions in the financial services industry
        on the availability of capital and financing.

Any of the above factors and numerous others not listed nor foreseen may adversely impact the Company's financial performance. Additional information on the potential factors that could affect the Company's actual results of operations is included in its filings with the Securities and Exchange Commission, which may be viewed on the Investor portal of the Company's Web Page at www.cleanharbors.com.

    CONTACT: Clean Harbors, Inc.
             James M. Rutledge, 781-792-5100
             Executive Vice President and Chief Financial Officer
             or
             Bill Geary, 781-792-5130
             Executive Vice President and General Counsel
             InvestorRelations@cleanharbors.com
             or
             Sharon Merrill Associates, Inc.
             Jim Buckley, 617-542-5300
             Executive Vice President
             clhb@investorrelations.com

    SOURCE: Clean Harbors, Inc.