Clean Harbors Files Registration Statement for a Public Offering of 2.3 Million Shares of Common Stock.

BRAINTREE, Mass. -- Clean Harbors, Inc. (NASDAQ: CLHB) today announced that it has filed a registration statement with the Securities and Exchange Commission relating to the public offering of up to 2,300,000 shares of its common stock, which includes 300,000 shares of common stock to cover over-allotment options. The net proceeds from the shares sold will be used to redeem 35% of the Company's outstanding 11.25% senior secured notes due 2012 and, to the extent any proceeds remain available thereafter, they will be used for general corporate purposes.

The offering will be lead managed by Credit Suisse First Boston. Needham & Company, LLC and Wedbush Morgan Securities will act as co-managers. The offering is subject to regulatory approvals, as well as customary closing and market conditions.

A registration statement relating to the common stock being offered has been filed with the Securities and Exchange Commission but has not yet become effective. The common stock may not be sold nor may offers to buy be accepted prior to the time the registration statement becomes effective. This announcement shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of the common stock in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state.

When available, a prospectus relating to the offering can be obtained from Credit Suisse First Boston LLC, 11 Madison Avenue, New York, NY 10010, or by phone at [phone].

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 48 waste management facilities, including nine landfills, five incineration locations and seven wastewater treatment centers, the Company provides essential services to over 45,000 customers, including more than 175 Fortune 500 companies, thousands of smaller private entities and numerous federal, state and local governmental agencies. Headquartered in Braintree, 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. Furthermore, all financial information in this press release is unaudited, and may change materially upon completion of the audit of the Company's financial statements. A variety of factors beyond the control of the Company affect the Company's performance, including, but not limited to:

--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;

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

--The Company's ability to manage the significant environmental liabilities, which it assumed in connection with the CSD acquisition; and

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

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, including but not limited to its Annual Report on Form 10-K/A, in its entirety and specifically Factors That May Affect Future Results under Item 7, for the fiscal year ended December 31, 2004, which was filed with the SEC on April 29, 2005, its Form 10-Q for the quarter ended March 31, 2005, which was filed on May 10, 2005 and Form 10-Q for the quarter ended June 30, 2005, which was filed on August 9, 2005.