Clean Harbors, Inc. (“ Clean Harbors” or the “ Company”) (NYSE: CLH) announced today that it is commencing a tender offer to purchase any and all of its outstanding $490.0 million aggregate principal amount of 7⅝% Senior Secured Notes due 2016 (the “ Notes”) through a cash tender offer (the “ Tender Offer”) with a portion of the proceeds from the Company’s concurrent private placement of Senior Notes due 2020 (the “ New Notes”), which was also announced today by the Company. The Tender Offer will expire at midnight New York City time on August 10, 2012, unless the Tender Offer is extended or earlier terminated (the “ expiration date”). Under the terms of the Tender Offer, holders of the Notes who validly tender and do not validly withdraw their Notes and consents prior to 5:00 p.m. New York City time on July 27, 2012, such time and date which may be extended (the “ consent date”) will receive an amount equal to $1,041.38 per $1,000.00 in principal amount of Notes validly tendered and not validly withdrawn, which amount is inclusive of a consent payment equal to $30.00 per $1,000.00 in principal amount of the Notes validly tendered and not validly withdrawn. Holders of the Notes who validly tender their Notes after the consent date but on or before the expiration date will receive an amount equal to $1,011.38 per $1,000.00 in principal amount of Notes validly tendered. Holders whose Notes are purchased in the Tender Offer will also be paid accrued and unpaid interest from the most recent interest payment date on the Notes to, but not including, the settlement date. In connection with the Tender Offer, the Company is soliciting the consents of holders of the Notes to certain proposed amendments to the indenture governing the Notes (the “ Consent Solicitation”). The primary purpose of the Consent Solicitation and proposed amendments is to eliminate substantially all of the restrictive covenants and certain events of default and related provisions and reduce the required notice period contained in the optional redemption provisions of the indenture. The Company intends to redeem any Notes that remain outstanding after the consummation of the Tender Offer at a price of $1,038.13 per $1,000.00 principal amount of Notes as promptly as practical in accordance with the terms of the indenture, as such indenture is amended pursuant to the proposed amendments. This press release does not constitute a notice of redemption under the optional redemption provisions of the indenture governing the Notes, nor does it constitute an offer to sell, or a solicitation of an offer to buy, any security. No offer, solicitation, or sale will be made in any jurisdiction in which such an offer, solicitation, or sale would be unlawful. This press release does not constitute an offer to sell or a solicitation of an offer to buy any of the New Notes, nor does it constitute an offer, solicitation or sale in any jurisdiction in which such offer, solicitation or sale is unlawful.