Clean Harbors, Inc. ("Clean Harbors") (NYSE: CLH) today announced that it has priced an add-on offering of $250.0 million aggregate principal amount of 5.125% Senior Notes due 2021 (the "Notes"). The offering size was increased from the previously announced $200.0 million. The Notes will be issued under the indenture pursuant to which Clean Harbors previously issued $600.0 million aggregate principal amount of 5.125% Senior Notes due 2021, $595.0 million aggregate principal amount of which remain outstanding. The Notes, which carry an interest rate of 5.125% per annum, were priced at 100.25% of the aggregate principal amount thereof. The offering is expected to close on or about March 17, 2016, subject to customary closing conditions. Clean Harbors intends to use the net proceeds from the offering of the Notes for potential future acquisitions and 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. About Clean HarborsClean Harbors (NYSE: CLH) is North America's leading provider of environmental, energy and industrial services. Clean Harbors serves a diverse customer base, including a majority of the Fortune 500, across the chemical, energy, manufacturing and additional markets, as well as numerous government agencies. These customers rely on Clean Harbors to deliver a broad range of services such as end-to-end hazardous waste management, emergency spill response, industrial cleaning and maintenance, and recycling services. Through its Safety-Kleen subsidiary, Clean Harbors also is North America's largest re-refiner and recycler of used oil and a leading provider of parts washers and environmental services to commercial, industrial and automotive customers. Founded in 1980 and based in Massachusetts, Clean Harbors operates throughout the United States, Canada, Mexico and Puerto Rico. The information made available in this news release contains forward-looking statements, which are generally statements about future events, plans, objectives and performance. Generally, the words "believe," "expect," "intend," "estimate," "anticipate," "project," "will" and similar expressions identify forward-looking statements. Forward-looking statements reflect Clean Harbors' current expectations, based on currently available information, and are not guarantees. Although Clean Harbors believes that the expectations reflected in such forward-looking statements are reasonable, these expectations could prove inaccurate as such statements involve risks and uncertainties, many of which are beyond Clean Harbors' ability to control or predict. Should one or more of these risks or uncertainties, or other risks or uncertainties not currently known to Clean Harbors or that Clean Harbors currently deems to be immaterial, materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those anticipated, estimated or projected.