Clean Harbors Commences Cash Tender Offer for up to $400,000,000 Aggregate Principal Amount of Its Outstanding 5.25% Senior Notes Due 2020

NORWELL, Mass.–(BUSINESS WIRE)–Clean Harbors, Inc. (NYSE: CLH) (“Clean Harbors,” the “Company” or “we”)
has commenced an offer to purchase for cash up to $400,000,000 aggregate
principal amount of the Company’s outstanding 5.25% Senior Notes due
2020 (the “Notes”) upon terms and subject to the conditions set forth in
an Offer to Purchase dated June 14, 2017, and a related Letter of
Transmittal.

Information relative to the tender offer is set forth in the table below.

The tender offer will expire at 11:59 p.m., New York City time on July
12, 2017, unless extended (such date and time, as the same may be
extended, the “Expiration Date”). Holders of Notes who validly tender
their Notes pursuant to the offer by 5:00 p.m., New York City time, on
June 27, 2017, unless extended (such date and time, as the same may be
extended, the “Early Participation Date”), will be paid, for each $1,000
principal amount of Notes accepted for purchase, cash in an amount equal
to $1,015.75 (the “Total Consideration”), which includes an early
participation payment of $50.00 per $1,000 principal amount of Notes
accepted for purchase (the “Early Participation Payment”). Holders who
validly tender their Notes after the Early Participation Date but prior
to the Expiration Date will be paid, for each $1,000 principal amount of
the Notes accepted for purchase, cash in an amount equal to the Total
Consideration minus the Early Participation Payment, or $965.75 (the
“Tender Offer Consideration”). Tendered Notes may be withdrawn at or
prior to 5:00 p.m., New York City time, on June 27, 2017, unless
extended.

Notes that are tendered and accepted for purchase at or prior to the
Early Participation Date will be settled only on the date that we refer
to as the “Initial Payment Date,” which will promptly follow the Early
Participation Date. We currently expect the Initial Payment Date to be
June 30, 2017. Notes that are tendered and accepted for purchase after
the Early Participation Date but before the Expiration Date will be
settled only on the date that we refer to as the “Final Payment Date,”
which will promptly follow the Expiration Date. We currently expect the
Final Payment Date to be July 14, 2017. If no additional Notes are
tendered after the Early Participation Date, or if the tender offer is
fully subscribed as of the Early Participation Date, there will be no
Final Payment Date.

In addition to the applicable Tender Offer Consideration or the Total
Consideration, as applicable, all Notes accepted for purchase will also
receive accrued and unpaid interest on such Notes from the last interest
payment date to, but not including, the Initial Payment Date or the
Final Payment Date, as applicable.

Subject to the terms and conditions of the Offer to Purchase (and any
amendments or supplements thereto), we will accept for payment only
validly tendered Notes up to an aggregate principal amount of Notes
equal to $400,000,000. If the aggregate principal amount of Notes
validly tendered exceeds $400,000,000, proration will occur if we accept
Notes for purchase pursuant to the Offer to Purchase. If the aggregate
principal amount of Notes validly tendered as of the Early Participation
Date is less than $400,000,000, Notes validly tendered after the Early
Participation Date may be subject to proration, whereas Notes validly
tendered at or prior to the Early Participation Date will not be subject
to proration. If the aggregate principal amount of Notes validly
tendered on or prior to the Early Participation Date equals or exceeds
$400,000,000, we will not accept any Notes for purchase after the Early
Participation Date, there will be no Final Payment Date and Notes
tendered on or prior to the Early Participation Date will be subject to
proration to the extent such tendered Notes exceed $400,000,000.

The Company will not be required to purchase any of the Notes tendered
unless certain conditions have been satisfied, including the receipt of
proceeds from a proposed Term Loan B facility debt financing on terms
satisfactory to the Company in an amount that, together with available
cash, will be sufficient to purchase $400,000,000 aggregate principal
amount of Notes and pay any premium, accrued and unpaid interest and
fees and expenses in connection therewith.

The Company reserves the right to increase the aggregate principal
amount of Notes to be accepted at any time, subject to compliance with
applicable law, which could result in purchasing a greater principal
amount of Notes in the tender offer. There can be no assurance that we
will exercise our right to increase the aggregate principal amount to be
accepted.

The tender offer is not conditioned on any minimum amount of Notes being
tendered but, if less than $400,000,000 principal amount of Notes are
purchased through the tender offer on the Initial Payment Date, the
Company expects to redeem, in accordance with the terms of the indenture
which governs the Notes, Notes having an aggregate principal amount
equal to any difference between $400,000,000 and the aggregate principal
amount of the Notes repurchased through the tender offer on the Initial
Payment Date. Under the indenture, the Notes may be redeemed on or after
August 1, 2017 for 101.313% of their principal amount, plus accrued
interest. However, there is no assurance that any such redemption will
occur.

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
will be 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.

Contacts

Investors:
Clean Harbors, Inc.
Jim
Buckley, 781-792-5100
SVP Investor Relations
[email protected]
or
Media:
Clean
Harbors, Inc.
Eric Kraus, 781-792-5100
EVP Corporate
Communications & Public Affairs
[email protected]