Clean Harbors, Inc. (“Clean Harbors”) (NYSE: CLH) announced today that it has priced a private placement of $800 million of Senior Notes due 2020 (the “Notes”). The size of the private placement was increased from the previously announced amount of $600 million. The Notes, which carry an interest rate of 5.25%, were priced at 100.0% of the aggregate principal amount. The transaction is expected to close on or about July 30, 2012, subject to customary closing conditions. Clean Harbors intends to use the net proceeds of the offering to purchase any and all of its outstanding 7.625% Senior Secured Notes due 2016 which are accepted for purchase in its concurrent tender offer and consent solicitation for such notes. Clean Harbors intends to use the remaining net proceeds from the offering to redeem any of its outstanding 7.625% Senior Secured Notes due 2016 not purchased in the tender offer and consent solicitation and for general corporate purposes. The Notes are being offered in the United States to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”), and outside the United States pursuant to Regulation S under the Securities Act. This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of, the Notes in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. The Notes will not be registered under the Securities Act or the securities laws of any other jurisdiction and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements. 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,” “estimates,” “projects,” or similar expressions. Such statements may include, but are not limited to, statements about Clean Harbors’ business outlook and financial guidance and other statements that are not historical facts. Such statements are based upon the beliefs and expectations of Clean Harbors’ management as of this date only and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, without limitation, those items identified as “risk factors” in Clean Harbors’ most recently filed Form 10-K and Form 10-Q. 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 various filings with the Securities and Exchange Commission, which may be viewed in the “Investors” section of Clean Harbors’ website at www.cleanharbors.com. About Clean Harbors Clean Harbors is the leading provider of environmental, energy and industrial services throughout North America. Clean Harbors serves more than 60,000 customers, including a majority of the Fortune 500 companies, thousands of smaller private entities and numerous federal, state, provincial and local governmental agencies. Headquartered in Norwell, Massachusetts, Clean Harbors has more than 200 locations, including over 50 waste management facilities, throughout North America in 37 U.S. states, seven Canadian provinces, Mexico and Puerto Rico. For more information, visit www.cleanharbors.com.