This announcement is not an offer to purchase or a solicitation of an offer to sell with respect to any Notes. Any offer to purchase the Notes is made by means of the Offer to Purchase and related Letter of Transmittal. No offer to purchase will be made in any jurisdiction in which such an offer to purchase would be unlawful.In connection with the tender offer, Clean Harbors has retained Goldman Sachs & Co. LLC as the Dealer Manager. Questions regarding the tender offer should be directed to the Dealer Manager at (800) 828-3182 (toll free) or (212) 357-1057 (collect). The complete terms and conditions of the offer are set forth in the Offer to Purchase and the related Letter of Transmittal, each dated June 14, 2017. Holders are urged to read those documents carefully. Requests for documents should be directed to Global Bondholder Services Corporation, the Information Agent for the tender offer, at (866) 794-2200 (toll free) or (212) 430-3774. About Clean Harbors Clean Harbors (NYSE: CLH) is North America's leading provider of environmental, energy and industrial services. The Company 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. 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. 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 future financial and operating results, 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 filings with the Securities and Exchange Commission, which may be viewed in the "Investors" section of Clean Harbors' website at www.cleanharbors.com.