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                                                                   Exhibit 10.49

                                                               EXECUTION VERSION
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                               CLEAN HARBORS, INC.


                           INVESTORS RIGHTS AGREEMENT


                            Dated as of June 30, 2004


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                                TABLE OF CONTENTS

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1.   DEFINITIONS..........................................................................1

2.   REGISTRATION UNDER THE SECURITIES ACT................................................5

     2.1.  Demand Registration............................................................5
     2.2.  Incidental Registration........................................................9
     2.3.  S-3 Registration; Shelf Registration..........................................11
     2.4.  Underwritten Offerings........................................................11
     2.5.  Expenses......................................................................12
     2.6.  Conversions; Exercises........................................................12
     2.7.  Registration Eligibility......................................................12

3.   HOLDBACK ARRANGEMENTS...............................................................13

     3.1.  Restrictions on Sale by Holders of Registrable Securities.....................13
     3.2.  Restrictions on Sale by the Company and Others................................13

4.   REGISTRATION PROCEDURES.............................................................13

     4.1.  Obligations of the Company....................................................13
     4.2.  Seller Information............................................................18
     4.3.  Notice to Discontinue.........................................................18

5.   INDEMNIFICATION; CONTRIBUTION.......................................................18

     5.1.  Indemnification by the Company................................................18
     5.2.  Indemnification by Holders....................................................19
     5.3.  Conduct of Indemnification Proceedings........................................19
     5.4.  Contribution..................................................................20
     5.5.  Indemnification Payments......................................................21
     5.6.  Other Indemnification.........................................................21

6.   GENERAL PROVISIONS REGARDING REGISTRATIONS..........................................21

     6.1.  Adjustments Affecting Registrable Securities..................................21
     6.2.  Registration Rights to Others.................................................21
     6.3.  Availability of Information; Rule 144; Rule 144A; Other Exemptions............21

7.   PROVISIONS APPLICABLE TO SECURITYHOLDERS............................................22

     7.1.  General Restriction...........................................................22
     7.2.  Right of Co-Sale..............................................................22
     7.3.  Permitted Transfers...........................................................23

8.   GENERAL.............................................................................23

     8.1.  Amendments and Waivers........................................................23
     8.2.  Notices.......................................................................24
     8.3.  Successors and Assigns........................................................24
     8.4.  Counterparts..................................................................25
     8.5.  Descriptive Headings, Etc.....................................................25
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     8.6.  Severability..................................................................25
     8.7.  CHOICE OF LAW AND VENUE; JURY TRIAL WAIVER....................................25
     8.8.  Remedies; Specific Performance................................................26
     8.9.  Entire Agreement..............................................................26
     8.10. Further Assurances............................................................27
     8.11. Construction..................................................................27
     8.12. No Inconsistent Agreement.....................................................27
     8.13. Costs and Attorneys' Fees.....................................................27
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                           INVESTORS RIGHTS AGREEMENT

          This INVESTORS RIGHTS AGREEMENT (this "AGREEMENT") is made and entered
into as of June 30, 2004, by and among Clean Harbors, Inc., a Massachusetts
corporation (the "COMPANY"), the investors identified as Initial Holders on the
signature pages hereto (the "INITIAL HOLDERS"), Alan S. McKim and the Trustees
of Alan S. McKim's Children's Trust (the "TRUST," and together with Alan S.
McKim, "MCKIM").

                              W I T N E S S E T H :

          WHEREAS, simultaneously herewith, the Company and the Initial Holders,
have entered into a Preferred Stock Redemption Agreement dated as of June 30,
2004 (the "REDEMPTION AGREEMENT"), pursuant to which the Company agreed, subject
to the terms and conditions therein stated, to redeem an aggregate of 25,000
shares of Series C Convertible Redeemable Preferred Stock, par value $0.01 per
share, of the Company (the "SERIES C PREFERRED STOCK") in exchange for cash and
the issuance to the Initial Holders of warrants (the "Warrants") to purchase an
aggregate of 2,775,000 share of Common Stock (as defined herein), subject to
adjustment as provided in the Warrants.

          WHEREAS, in connection with the Redemption Agreement, (i) the Company
is hereby granting the Initial Holders registration rights and certain other
rights and (ii) McKim, who will benefit as a significant shareholder of the
Company by the Initial Holders agreeing to have the Series C Preferred Stock
redeemed by the Company under the Redemption Agreement, is hereby granting the
Initial Holders the right to tag-along to certain sales of Company securities by
McKim, all subject to the terms and conditions of this Agreement.

          NOW, THEREFORE, in consideration of the premises and of the mutual
covenants and agreements contained herein and for other good and valuable
consideration the receipt and sufficiency of which is hereby acknowledged, and
intending to be legally bound hereby, the parties hereto agree as follows:

          1.   DEFINITIONS. As used in this Agreement, the following terms shall
have the following meanings:

          "AFFILIATE" shall mean (i) with respect to any Person, any other
Person directly or indirectly controlling or controlled by or under direct or
indirect common control with such Person, and (ii) with respect to any
individual, shall also mean the spouse, sibling, child, step-child, grandchild,
niece, nephew or parent of such Person, or the spouse thereof.

          "AGENTS" shall have the meaning set forth in Section 5.1.

          "AGREEMENT" shall have the meaning set forth in the preamble.

          "COMMON STOCK" shall mean shares of common stock, par value $.01 per
share, of the Company.

          "COMPANY" shall have the meaning set forth in the preamble.

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          "CONVEY" has the meaning set forth in Section 7.1.

          "DEMAND REGISTRATION" shall mean a registration required to be
effected by the Company pursuant to Section 2.1.

          "DEMAND REGISTRATION STATEMENT" shall mean a registration statement of
the Company which covers the Registrable Securities requested to be included
therein pursuant to the provisions of Section 2.1 and all amendments and
supplements to such registration statement, including post-effective amendments,
in each case including the Prospectus contained therein, all exhibits thereto
and all material incorporated by reference (or deemed to be incorporated by
reference) therein.

          "ENCUMBRANCE" shall mean any lien, claim, charge, security interest,
mortgage, pledge, easement, conditional sale or other title retention agreement,
defect in title, covenant or other restriction of any kind.

          "EXCHANGE ACT" shall mean the Securities Exchange Act of 1934, as
amended from time to time, and the rules and regulations thereunder, or any
successor statute.

          "GOVERNMENTAL ENTITY" shall mean any domestic (federal and state),
foreign or supranational court, commission, governmental body, regulatory
agency, authority or tribunal.

          "HOLDERS" shall mean the Initial Holders for so long as they are the
registered owner of any Registrable Securities and such of their heirs,
successors and permitted assigns (including any permitted transferees of
Registrable Securities) who acquire or are otherwise the transferee of
Registrable Securities, directly or indirectly, from any Initial Holder (or any
subsequent Holder), for so long as such heirs, successors and permitted assigns
are the registered owner of any Registrable Securities. For purposes of this
Agreement, a Person will be deemed to be a Holder whenever such Person holds an
option to purchase, or a security convertible into or exercisable or
exchangeable for, Registrable Securities (including the Warrants), whether or
not such purchase, conversion, exercise or exchange has actually been effected
and disregarding any legal restrictions upon the exercise of such rights.
Registrable Securities issuable upon exercise of an option or upon conversion,
exchange or exercise of another security shall be deemed outstanding for the
purposes of this Agreement.

          "HOLDER'S COUNSEL" shall mean one firm of counsel (per registration)
to the Holders of Registrable Securities participating in such registration,
which counsel shall be selected (i) in the case of a Demand Registration, by the
Initiating Holders holding a majority of the Registrable Securities for which
registration was requested in the Request, and (ii) in all other cases, by the
Majority Holders of the Registration.

          "INCIDENTAL REGISTRATION" shall mean a registration required to be
effected by the Company pursuant to Section 2.2.

          "INCIDENTAL REGISTRATION STATEMENT" shall mean a registration
statement of the Company, which covers the Registrable Securities requested to
be included therein pursuant to the provisions of Section 2.2 and all amendments
and supplements to such registration statement, including post-effective
amendments, in each case including the Prospectus contained therein, all

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exhibits thereto and all material incorporated by reference (or deemed to be
incorporated by reference) therein.

          "INITIAL HOLDERS" shall have the meaning set forth in the preamble.

          "INITIATING HOLDERS" shall mean, with respect to a particular
registration, the Holders who initiated the Request for such registration.

          "INSPECTOR" or "INSPECTORS" has the meaning set forth in Section
4.1(g).

          "MAJORITY HOLDERS" shall mean one or more Holders of Registrable
Securities who would hold a majority of the Registrable Securities then
outstanding.

          "MAJORITY HOLDERS OF THE REGISTRATION" shall mean, with respect to a
particular registration, one or more Holders of Registrable Securities who would
hold a majority of the Registrable Securities to be included in such
registration.

          "MCKIM" has the meaning set forth in the preamble.

          "NASD" shall mean the National Association of Securities Dealers, Inc.

          "NASDAQ NATIONAL MARKET" shall have the meaning set forth in Section
4.1(k).

          "NO-ACTION LETTER" shall have the meaning set forth in Section 2.7

          "PERMITTED FAMILY TRANSFEREE" has the meaning set forth in Section
7.3.

          "PERSON" shall mean any individual, firm, partnership, corporation,
trust, joint venture, association, joint stock company, limited liability
company, unincorporated organization or any other entity or organization,
including a government or agency or political subdivision thereof, and shall
include any successor (by merger or otherwise) of such entity.

          "PRO RATA SHARE" has the meaning set forth in Section 7.2(a).

          "PROSPECTUS" shall mean the prospectus included in a Registration
Statement (including, without limitation, any preliminary prospectus and any
prospectus that includes any information previously omitted from a prospectus
filed as part of an effective registration statement in reliance upon Rule 430A
promulgated under the Securities Act) and any such Prospectus as amended or
supplemented by any prospectus supplement, and all other amendments and
supplements to such Prospectus, including post-effective amendments, and in each
case including all material incorporated by reference (or deemed to be
incorporated by reference) therein.

          "PURCHASER" has the meaning set forth in Section 7.2(a).

          "PURCHASE OFFER" has the meaning set forth in Section 7.2(a).

          "RECORDS" shall have the meaning set forth in Section 4.1(g).

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          "REDEMPTION AGREEMENT" has the meaning set forth in the first recital.

          "REGISTRABLE SECURITIES" shall mean (i) any Warrant Shares, and (ii)
any other securities of the Company (or any successor or assign of the Company,
whether by merger, consolidation, sale of assets or otherwise) which may be
issued with respect to, in exchange for, or in substitution of, Warrant Shares
by reason of any dividend or stock split, combination of shares, merger,
consolidation, recapitalization, reclassification, reorganization, sale of
assets or similar transaction. As to any particular Registrable Securities, such
securities shall cease to be Registrable Securities when (A) a registration
statement with respect to the sale of such securities shall have been declared
effective under the Securities Act and such securities shall have been disposed
of in accordance with such registration statement, (B) such securities are sold
pursuant to Rule 144 (or any similar provisions then in force) under the
Securities Act, (C) such securities have been otherwise transferred and a new
certificate or other evidence of ownership for them not bearing the legend
restricting further transfer shall have been delivered by the Company and
subsequent public distribution of them shall not require registration under the
Securities Act, or (D) such securities shall have ceased to be outstanding.

          "REGISTRATION EXPENSES" shall mean any and all reasonable out of
pocket expenses incident to performance of or compliance with this Agreement by
the Company and its subsidiaries, including, without limitation (i) all SEC,
stock exchange, NASD and other registration, listing and filing fees, (ii) all
fees and expenses incurred in connection with compliance with state securities
or blue sky laws and compliance with the rules of any stock exchange (including
fees and disbursements of counsel in connection with such compliance and the
preparation of a blue sky memorandum and legal investment survey), (iii) all
printers' fees and costs incurred in printing, distributing, mailing and
delivering any Registration Statement, any Prospectus and any other document
relating to the performance of or compliance with this Agreement, (iv) the fees
and disbursements of counsel for the Company, (v) the fees and disbursements of
Holders' Counsel, (vi) the fees and disbursements of all independent public
accountants (including the expenses of any audit and/or "cold comfort" letters)
and the fees and expenses of other Persons, including experts, retained by the
Company, (vii) the expenses incurred in connection with making road show
presentations and holding meetings with potential investors to facilitate the
distribution and sale of Registrable Securities, (viii) any fees and
disbursements of underwriters customarily paid by issuers or sellers of
securities, (ix) premiums and other costs of policies of insurance against
liabilities arising out of the public offering of the Registrable Securities
being registered, and (x) all internal expenses of the Company (including all
salaries and expenses of officers and employees performing legal or accounting
duties); PROVIDED, HOWEVER, Registration Expenses shall not include discounts
and commissions payable to underwriters, selling brokers, dealer managers or
other similar Persons engaged in the distribution of any of the Registrable
Securities; PROVIDED, FURTHER, that in any case where Registration Expenses are
not to be borne by the Company, such expenses shall not include salaries of
Company personnel or general overhead expenses of the Company, auditing fees,
premiums or other expenses relating to liability insurance required by
underwriters of the Company or other expenses for the preparation of financial
statements or other data normally prepared by the Company in the ordinary course
of its business or which the Company would have incurred in any event; and
PROVIDED, FURTHER, that in the event the Company shall not register any
securities with respect to which it had given written notice of its intention to
register

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to Holders, notwithstanding anything to the contrary in the foregoing, all of
the costs incurred by the Holders in connection with such registration shall be
deemed to be Registration Expenses.

          "REGISTRATION STATEMENT" shall mean any registration statement of the
Company which covers any Registrable Securities and all amendments and
supplements to any such Registration Statement, including post-effective
amendments, in each case including the Prospectus contained therein, all
exhibits thereto and all material incorporated by reference (or deemed to be
incorporated by reference) therein.

          "REQUEST" shall have the meaning set forth in Section 2.1(a).

          "SEC" shall mean the Securities and Exchange Commission, or any
successor agency having jurisdiction to enforce the Securities Act.

          "SECURITIES ACT" shall mean the Securities Act of 1933, as amended
from time to time, and the rules and regulations thereunder, or any successor
statute.

          "SERIES C PREFERRED STOCK" shall have the meaning set forth in the
first recital.

          "SHELF REGISTRATION" shall have the meaning set forth in Section
2.1(a).

          "STOCKHOLDERS" shall mean, collectively, the holders of Common Stock.

          "UNDERWRITERS" shall mean the underwriters, if any, of the offering
being registered under the Securities Act.

          "UNDERWRITTEN OFFERING" shall mean a sale of securities of the Company
to an Underwriter or Underwriters for reoffering to the public.

          "WARRANT SHARES" shall mean the shares of Common Stock or other
securities issued or issuable upon exercise of the Warrants.

          "WITHDRAWN DEMAND REGISTRATION" shall have the meaning set forth in
Section 2.1(a).

          "WITHDRAWN REQUEST" shall have the meaning set forth in Section
2.1(a).

          2. REGISTRATION UNDER THE SECURITIES ACT.

               2.1. DEMAND REGISTRATION.

                      (a)  RIGHT TO DEMAND REGISTRATION. Subject to Section
2.1(c) and Section 2.7 hereof, at any time or from time to time, any Initial
Holder (or an assignee to whom such Initial Holder has expressly delegated or
assigned all or any portion of its rights under this sentence) shall have the
right to request in writing that the Company register all or part of such
Holders' Registrable Securities (a "REQUEST") (which Request shall specify the
amount of Registrable Securities intended to be disposed of by such Holders and
the intended method of disposition thereof) by filing with the SEC a Demand
Registration Statement. As promptly as

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practicable, but no later than 15 days after receipt of a Request, the Company
shall give written notice of such requested registration to all other Holders of
Registrable Securities. Subject to Section 2.1(b), the Company shall include in
a Demand Registration (A) the Registrable Securities intended to be disposed of
by the Initiating Holders and (B) the Registrable Securities intended to be
disposed of by any other Holder which shall have made a written request (which
request shall specify the amount of Registrable Securities to be registered and
the intended method of disposition thereof) to the Company for inclusion thereof
in such registration within 20 days after the receipt of such written notice
from the Company. The Company shall, as expeditiously as reasonably practicable
following a Request, use its best efforts to cause to be filed with the SEC a
Demand Registration Statement providing for the registration under the
Securities Act of the Registrable Securities which the Company has been so
requested to register by all such Holders, to the extent necessary to permit the
disposition of such Registrable Securities to be registered in accordance with
the intended methods of disposition thereof specified in such Request or further
requests (including, without limitation, by means of a shelf registration
pursuant to Rule 415 under the Securities Act (a "SHELF REGISTRATION") if so
requested and if the Company is then eligible to use such a registration). The
Company shall use its best efforts to have such Demand Registration Statement
declared effective by the SEC as soon as practicable thereafter and to keep such
Demand Registration Statement continuously effective for the period specified in
Section 4.1(b).

                           (i)   A Request may be withdrawn prior to the filing
     of the Demand Registration Statement by the Majority Holders of the
     Registration (a "WITHDRAWN REQUEST") and a Demand Registration Statement
     may be withdrawn prior to the effectiveness thereof by the Majority Holders
     of the Registration (a "WITHDRAWN DEMAND REGISTRATION"), and such
     withdrawals shall be treated as a Demand Registration which shall have been
     effected pursuant to this Section 2.1, unless the Holders of Registrable
     Securities to be included in such Registration Statement reimburse the
     Company for its reasonable out-of-pocket Registration Expenses relating to
     the preparation and filing of such Demand Registration Statement (to the
     extent actually incurred), in which case such withdrawal shall not be
     treated as a Demand Registration effected pursuant to this Section 2.1 (and
     shall not be counted toward the number of Demand Registrations); PROVIDED,
     HOWEVER, that if a Withdrawn Request or Withdrawn Registration Statement is
     made (A) because of a material adverse change in the business, financial
     condition or prospects of the Company, or (B) because the sole or lead
     managing Underwriter advises that the amount of Registrable Securities to
     be sold in such offering be reduced pursuant to Section 2.1(b) by more than
     15% of the Registrable Securities to be included in such Registration
     Statement, then such withdrawal shall not be treated as a Demand
     Registration effected pursuant to this Section 2.1 (and shall not be
     counted toward the number of Demand Registrations) and the Company shall
     pay all Registration Expenses in connection therewith, and, PROVIDED
     FURTHER, that if a Withdrawn Request or Withdrawn Demand Registration is
     made with respect to a Request or Demand Registration Statement of which
     Basso, as defined below, is the Initiating Holder, the Company shall
     continue to effect the Demand Registration in accordance with this
     Agreement with respect to the Registrable Securities sought to be
     registered by Basso. Any Holder requesting inclusion in a Demand
     Registration may, at any time prior to the effective date of the Demand
     Registration Statement (and for any reason) revoke

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     such request by delivering written notice to the Company revoking such
     requested inclusion.

                           (ii)  The registration rights granted pursuant to the
     provisions of this Section 2.1 shall be in addition to the registration
     rights granted pursuant to the other provisions of Section 2 hereof.

                      (b)  PRIORITY IN DEMAND REGISTRATIONS. If a Demand
Registration involves an Underwritten Offering, and the sole or lead managing
Underwriter, as the case may be, of such Underwritten Offering shall advise the
Company in writing (with a copy to each Holder requesting registration) on or
before the date five days prior to the date then scheduled for such offering
that, in its opinion, the amount of Registrable Securities requested to be
included in such Demand Registration exceeds the number which can be sold in
such offering within a price range acceptable to the Majority Holders of the
Registration (such writing to state the basis of such opinion and the
approximate number of Registrable Securities which may be included in such
offering), and the Request is not thereafter withdrawn, the Company shall
include in such Demand Registration, to the extent of the number which the
Company is so advised may be included in such offering, the Registrable
Securities requested to be included in the Demand Registration by the Holders
allocated PRO RATA in proportion to the number of Registrable Securities
requested to be included in such Demand Registration by each of such Holders. In
the event the Company shall not, by virtue of this Section 2.1(b), include in
any Demand Registration all of the Registrable Securities of any Holder
requested to be included in such Demand Registration, such Holder may, upon
written notice to the Company given within five days of the date such Holder
first is notified of such matter, further reduce the amount of Registrable
Securities it desires to have included in such Demand Registration, whereupon
only the Registrable Securities, if any, that it desires to have included will
be so included and the Holders not so reducing shall be entitled to a
corresponding PRO RATA increase in the amount of Registrable Securities to be
included in such Demand Registration.

                      (c)  LIMITATIONS ON REGISTRATIONS. The rights of Holders
of Registrable Securities to request Demand Registrations pursuant to Section
2.1(a) are subject to the following limitations: in no event shall the Company
be required to effect a Demand Registration unless the aggregate offering price,
net of underwriting discounts and commissions, is at least $1,000,000; PROVIDED,
HOWEVER, that the Company shall be required to effect a Demand Registration
regardless of the aggregate offering price in the event that the Majority
Holders are disposing of all of the Registrable Securities held by them; and
(iii) in no event shall the Company be required to effect more than (A) two
Demand Registrations for the benefit of Cerberus CH LLC, an Initial Holder, and
its successors and assigns, (B) one Demand Registration for the benefit of all
of the Initial Holders that are Affiliates of Oak Hill Advisors, Inc. ("Oak
Hill") or accounts or funds that Oak Hill or its Affiliates control or advise,
and their successor and assigns and (C) one Demand Registration for the benefit
of Basso Holdings Ltd., an Initial Holder, and its successors and assigns
(collectively, "Basso"); PROVIDED, HOWEVER, that such number shall be increased
to the extent the Company (x) does not include in what would otherwise be the
final registration for which the Company is required to pay Registration
Expenses the number of Registrable Securities requested to be registered by the
Holders by reason of Section 2.1(b) or (y) terminates a Shelf Registration
pursuant to Section 2.3 prior to the time that all Registrable Securities
covered by such Shelf Registration have been sold; and

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PROVIDED, FURTHER, that the Registration Expenses in connection with each
additional Demand Registration shall be allocated PRO RATA among all Persons on
whose behalf securities of the Company are included in such registration, on the
basis of the respective amounts of the securities then being registered on their
behalf.

                      (d)  UNDERWRITING; SELECTION OF UNDERWRITERS.
Notwithstanding anything to the contrary contained in Section 2.1(a), if the
Initiating Holders holding a majority of the Registrable Securities for which
registration was requested in the Request so elect, the offering of such
Registrable Securities pursuant to such Demand Registration shall be in the form
of a firm commitment Underwritten Offering and such Initiating Holders may
require that all Persons (including other Holders) participating in such
registration sell their Registrable Securities to the Underwriters at the same
price and on the same terms of underwriting applicable to the Initiating
Holders. If any Demand Registration involves an Underwritten Offering, the sole
or managing Underwriters and any additional investment bankers and managers to
be used in connection with such registration shall be selected by the Company
subject to the approval of the Majority Holders of the Registration.

                      (e)  EFFECTIVE REGISTRATION STATEMENT; SUSPENSION. A
Demand Registration Statement shall not be deemed to have become effective (and
the related registration will not be deemed to have been effected) (i) unless it
has been declared effective by the SEC and remains effective in compliance with
the provisions of the Securities Act with respect to the disposition of all
Registrable Securities covered by such Demand Registration Statement for the
time period specified in Section 4.1(b), (ii) if the offering of any Registrable
Securities pursuant to such Demand Registration Statement is interfered with by
any stop order, injunction or other order or requirement of the SEC or any other
governmental agency or court, or (iii) if, in the case of an Underwritten
Offering, the conditions to closing specified in an underwriting agreement to
which the Company is a party are not satisfied (other than by the sole reason of
any breach or failure by the Holders of Registrable Securities) and are not
otherwise waived.

                      (f)  REGISTRATION STATEMENT FORM. Registrations under this
Section 2.1 shall be on Form S-3 (or a successor form thereto adopted by the
SEC) or, if such Form is not then available, on such other appropriate
registration form of the SEC as shall be selected by the Initiating Holders
holding a majority of the Registrable Securities for which the registration was
requested in the Request and which shall be available for the sale of
Registrable Securities in accordance with the intended method or methods of
disposition specified in the requests for registration. The Company agrees to
include in any such Registration Statement all information which any selling
Holder, upon advice of counsel, shall reasonably request.

                      (g)  OTHER REGISTRATIONS. During the period (i) beginning
on the date of a Request and (ii) ending on the date that is 90 days after the
date that a Demand Registration Statement filed pursuant to such Request has
been declared effective by the SEC or, if the Holders shall withdraw such
Request or such Demand Registration Statement, on the date of such Withdrawn
Request or such Withdrawn Registration Statement, the Company shall not, without
the consent of the Majority Holders of the Registration, file a registration
statement pertaining to any other securities of the Company.

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               2.2. INCIDENTAL REGISTRATION.

                      (a)  RIGHT TO INCLUDE REGISTRABLE SECURITIES. (i) If the
Company at any time or from time to time proposes to register any of its
securities under the Securities Act (other than in a registration on Form S-4 or
S-8 or any successor form to such forms and other than pursuant to Section 2.1
or 2.3) whether or not pursuant to registration rights granted to other holders
of its securities and whether or not for sale for its own account, the Company
shall deliver prompt written notice (which notice shall be given at least 45
days prior to such proposed registration) to all Holders of Registrable
Securities of its intention to undertake such registration, describing in
reasonable detail the proposed registration and distribution (including the
anticipated range of the proposed offering price, the class and number of
securities proposed to be registered and the distribution arrangements) and of
such Holders' right to participate in such registration under this Section 2.2
as hereinafter provided. Subject to the other provisions of this Section 2.2(a)
and Section 2.2(b), upon the written request of any Holder made within 30 days
after the receipt of such written notice (which request shall specify the amount
of Registrable Securities to be registered and the intended method of
disposition thereof), the Company shall effect the registration under the
Securities Act of all Registrable Securities requested by Holders to be so
registered (an "INCIDENTAL REGISTRATION"), to the extent required to permit the
disposition (in accordance with the intended methods thereof as aforesaid) of
the Registrable Securities so to be registered, by inclusion of such Registrable
Securities in the Registration Statement which covers the securities which the
Company proposes to register and shall cause such Registration Statement to
become and remain effective with respect to such Registrable Securities in
accordance with the registration procedures set forth in Section 4. If an
Incidental Registration involves an Underwritten Offering, immediately upon
notification to the Company from the Underwriter of the price at which such
securities are to be sold, the Company shall so advise each participating
Holder. The Holders requesting inclusion in an Incidental Registration may, at
any time prior to the effective date of the Incidental Registration Statement
(and for any reason), revoke such request by delivering written notice to the
Company revoking such requested inclusion.

                           (ii)  If at any time after giving written notice of
     its intention to register any securities and prior to the effective date of
     the Incidental Registration Statement filed in connection with such
     registration, the Company shall determine for any reason not to register or
     to delay registration of such securities, the Company may, at its election,
     give written notice of such determination to each Holder of Registrable
     Securities and, thereupon, (A) in the case of a determination not to
     register, the Company shall be relieved of its obligation to register any
     Registrable Securities in connection with such registration (but not from
     its obligation to pay the Registration Expenses incurred in connection
     therewith), without prejudice, however, to the rights of Holders to cause
     such registration to be effected as a registration under Section 2.1 and
     (B) in the case of a determination to delay such registration, the Company
     shall be permitted to delay the registration of such Registrable Securities
     for the same period as the delay in registering such other securities;
     PROVIDED, HOWEVER, that if such delay shall extend beyond 120 days from the
     date the Company received a request to include Registrable Securities in
     such Incidental Registration, then the Company shall again give all Holders
     the opportunity to participate therein and shall follow the notification
     procedures set forth in the preceding paragraph. There is no limitation on
     the number of

                                        9
<Page>

     such Incidental Registrations pursuant to this Section 2.2 which the
     Company is obligated to effect.

                           (iii) The registration rights granted pursuant to the
     provisions of this Section 2.2 shall be in addition to the registration
     rights granted pursuant to the other provisions of Section 2 hereof.

                      (b)  PRIORITY IN INCIDENTAL REGISTRATION. If an Incidental
Registration involves an Underwritten Offering (on a firm commitment basis), and
the sole or the lead managing Underwriter, as the case may be, of such
Underwritten Offering shall advise the Company in writing (with a copy to each
Holder requesting registration) on or before the date five days prior to the
date then scheduled for such offering that, in its opinion, the amount of
securities (including Registrable Securities) requested to be included in such
registration exceeds the amount which can be sold in such offering without
materially interfering with the successful marketing of the securities being
offered (such writing to state the basis of such opinion and the approximate
number of such securities which may be included in such offering without such
effect), the Company shall include in such registration, to the extent of the
number which the Company is so advised may be included in such offering without
such effect, (i) in the case of a registration initiated by the Company, (A)
first, the securities that the Company proposes to register for its own account
(but solely to the extent that the proceeds thereof shall not be used to
purchase shares of common stock of the Company or other securities of the
Company), (B) second, the Registrable Securities requested to be included in
such registration by the Holders, allocated PRO RATA in proportion to the number
of Registrable Securities requested to be included in such registration by each
of such Holders, and (C) third, other securities of the Company to be registered
on behalf of any other Person, and (ii) in the case of a registration initiated
by a Person other than the Company, (A) first, the Registrable Securities
requested to be included in such registration by the Holders, and any Persons
initiating such registration, allocated PRO RATA in proportion to the number of
securities requested to be included in such registration by each of them, (B)
second, the securities that the Company proposes to register for its own
account, and (C) third, the securities of the Company to be registered on behalf
of any other Person; PROVIDED, HOWEVER, that in the event the Company will not,
by virtue of this Section 2.2(b), include in any such registration all of the
Registrable Securities of any Holder requested to be included in such
registration, such Holder may, upon written notice to the Company given within
three days of the time such Holder first is notified of such matter, reduce the
amount of Registrable Securities it desires to have included in such
registration, whereupon only the Registrable Securities, if any, it desires to
have included will be so included and the Holders not so reducing shall be
entitled to a corresponding pro rata increase in the amount of Registrable
Securities to be included in such registration.

                      (c)  SELECTION OF UNDERWRITERS. If any Incidental
Registration involves an Underwritten Offering, the sole or managing
Underwriter(s) and any additional investment bankers and managers to be used in
connection with such registration shall be subject to the approval of the
Majority Holders of the Registration (such approval not to be unreasonably
withheld).

                                       10
<Page>

               2.3.   S-3 REGISTRATION; SHELF REGISTRATION.

                      (a)  SHELF REGISTRATION. If a request made pursuant to
Section 2.1 is for a Shelf Registration, subject to Section 2.7, the Company
shall use its best efforts to keep the Shelf Registration continuously effective
through the date on which all of the Registrable Securities covered by such
Shelf Registration may be sold pursuant to Rule 144(k) under the Securities Act
(or any successor provision having similar effect); PROVIDED, HOWEVER, that
prior to the termination of such Shelf Registration, the Company shall first
furnish to each Holder of Registrable Securities participating in such Shelf
Registration (i) an opinion, in form and substance satisfactory to the Majority
Holders of the Registration, of counsel for the Company satisfactory to the
Majority Holders of the Registration stating that such Registrable Securities
are freely saleable pursuant to Rule 144(k) under the Securities Act (or any
successor provision having similar effect) or (ii) a "No-Action Letter" from the
staff of the SEC stating that the SEC would not recommend enforcement action if
the Registrable Securities included in such Shelf Registration were sold in a
public sale other than pursuant to an effective registration statement.

               2.4.   UNDERWRITTEN OFFERINGS.

                      (a)  DEMAND UNDERWRITTEN OFFERINGS. If requested by the
sole or lead managing Underwriter for any Underwritten Offering effected
pursuant to a Demand Registration, the Company shall enter into a customary
underwriting agreement with the Underwriters for such offering, such agreement
to be reasonably satisfactory in substance and form to the Company and each
Holder of Registrable Securities participating in such offering and to contain
such representations and warranties by the Company and such other terms as are
generally prevailing in agreements of that type, including, without limitation,
indemnification and contribution to the effect and to the extent provided in
Section 5.

                      (b)  HOLDERS OF REGISTRABLE SECURITIES TO BE PARTIES TO
UNDERWRITING AGREEMENT. The Holders of Registrable Securities to be distributed
by Underwriters in an Underwritten Offering contemplated by Section 2 shall be
parties to the underwriting agreement between the Company and such Underwriters
and may, at such Holders' option, require that any or all of the representations
and warranties by, and the other agreements on the part of, the Company to and
for the benefit of such Underwriters shall also be made to and for the benefit
of such Holders of Registrable Securities and that any or all of the conditions
precedent to the obligations of such Underwriters under such underwriting
agreement be conditions precedent to the obligations of such Holders of
Registrable Securities; PROVIDED, HOWEVER, that the Company shall not be
required to make any representations or warranties with respect to written
information specifically provided by a selling Holder for inclusion in the
Registration Statement. No Holder shall be required to make any representations
or warranties to, or agreements with, the Company or (in the case of an
Incidental Registration) the Underwriters other than representations, warranties
or agreements regarding such Holder, such Holder's Registrable Securities and
such Holder's intended method of disposition.

                      (c)  PARTICIPATION IN UNDERWRITTEN REGISTRATION.
Notwithstanding anything herein to the contrary, no Person may participate in
any underwritten registration hereunder unless such Person (i) agrees to sell
its securities on the same terms and

                                       11
<Page>

conditions provided in any underwritten arrangements approved by the Persons
entitled hereunder to approve such arrangement and (ii) accurately completes and
executes in a timely manner all questionnaires, powers of attorney, indemnities,
custody agreements, underwriting agreements and other documents reasonably
required under the terms of such underwriting arrangements.

               2.5.   EXPENSES. The Company shall pay all Registration Expenses
in connection with any Demand Registration, Incidental Registration or Shelf
Registration whether or not such registration shall become effective and whether
or not all Registrable Securities originally requested to be included in such
registration are withdrawn or otherwise ultimately not included in such
registration, except as otherwise provided with respect to a Withdrawn Request
and a Withdrawn Demand Registration in Section 2.1(a).

               2.6.   CONVERSIONS; EXERCISES. Notwithstanding anything to the
contrary herein, in order for any Registrable Securities that are issuable upon
the exercise of conversion rights, options or warrants to be included in any
registration pursuant to Section 2 hereof, the exercise of such conversion
rights, options or warrants must be effected no later than immediately prior to
the closing of any sales under the Registration Statement pursuant to which such
Registrable Securities are to be sold.

               2.7.   REGISTRATION ELIGIBILITY. The Company and each Initial
Holder acknowledge that the Company is operating on the date hereof pursuant a
No-Action Letter from the SEC in the form attached hereto as EXHIBIT A (the
"NO-ACTION LETTER"), which may limit the Company's ability to have Registration
Statements covering Registrable Securities declared effective by the SEC. In
light of the foregoing, the Company and the Initial Holders agree that if the
Company, solely by virtue of the limitations expressly set forth in the
No-Action Letter, is unable to have any Registration Statement covering
Registrable Securities declared effective by the SEC, the Company shall not be
in breach of its obligation to register Registrable Securities pursuant to this
Agreement if, and only, if during the effectiveness of this Agreement (whether
or not a Request is pending) the Company is using its best efforts to remedy the
condition giving rise to such limitations expressed in the No-Action Letter,
which "best efforts" shall include, but not be limited to, (a) seeking further
effective waivers or no-action relief (to the extent, if any, then required)
from the SEC no later than the earlier of (i) the date thirty (30) days after a
Request is made to register Registrable Securities and (ii) 120 days after
December 31, 2004 (and, to the extent such relief is not granted, seeking such
waivers or no-action relief on a no less frequent basis than annually following
each prior request until such relief is granted), to the effect that the Company
may register the Registrable Securities with the SEC without compliance by the
Company with the requirement to file historical audited financial statements for
the CSD, and (b) taking such other actions as are reasonably requested by the
Holders or that would otherwise reasonably be expected to allow the Company to
register Registrable Securities without complying with SEC rules and regulations
concerning the filing of historical audited financial statements for the CSD.
The Company shall not seek no-action or other relief from the SEC with regard to
the registration of any other securities of the Company unless at the same time
and on at least as favorable a basis the Company seeks relief with regard to the
registration of Registrable Securities.

                                       12
<Page>

          3. HOLDBACK ARRANGEMENTS.

               3.1.   RESTRICTIONS ON SALE BY HOLDERS OF REGISTRABLE SECURITIES.
Each Holder of Registrable Securities agrees, by acquisition of such Registrable
Securities, if timely requested in writing by the sole or lead managing
Underwriter, not to make any short sale of, loan, grant any option for the
purchase of or effect any public sale or distribution, of any of the Company's
equity securities (or any security convertible into or exchangeable or
exercisable for any of the Company's equity securities) during the time period
reasonably requested by the sole or lead managing Underwriter not to exceed 90
days, beginning on the effective date of the applicable registration statement
(except as part of such underwritten registration or pursuant to registrations
on Forms S-4 or S-8 or any successor form to such forms), unless the sole or
lead Managing Underwriter in such Underwritten Offering otherwise agrees;
PROVIDED, HOWEVER, that to the extent the Company or the sole lead Managing
Underwriter releases any Person from the foregoing restrictions in whole or in
part it shall, on the same day, notify the Initial Holder of such release and
such parties shall automatically be released to the same extent.

               3.2.   RESTRICTIONS ON SALE BY THE COMPANY AND OTHERS. The
Company and McKim agree that if timely requested in writing by the sole or lead
managing Underwriter in an Underwritten Offering of any Registrable Securities,
not to make any short sale of, loan, grant any option for the purchase of or
effect any public sale or distribution of any of the Company's equity securities
(or any security convertible into or exchangeable or exercisable for any of the
Company's equity securities) during the nine business days (as such term is used
in Rule 10b-6 under the Exchange Act) prior to, and during the time period
reasonably requested by the sole or lead managing Underwriter not to exceed 180
days, beginning on the effective date of the applicable registration statement
(except as part of such underwritten registration or pursuant to registrations
on Forms S-4 or S-8 or any successor form to such forms), unless the sole or
lead Managing Underwriter in such Underwritten Offering otherwise agrees. The
Company will use its reasonable best efforts to cause each director or officer
of the Company and each holder of 5% or more of the equity securities (or any
security convertible into or exchangeable or exercisable for any of its equity
securities) of the Company purchased from the Company at any time after the date
of this Agreement (other than in a registered public offering or in a public
sale) to so agree.

          4. REGISTRATION PROCEDURES.

               4.1.   OBLIGATIONS OF THE COMPANY. Whenever the Company is
required to effect the registration of Registrable Securities under the
Securities Act pursuant to Section 2 of this Agreement, the Company shall, as
expeditiously as possible:

                      (a)  prepare and file with the SEC (promptly, and in any
event within 60 days after receipt of a request to register Registrable
Securities) the requisite Registration Statement to effect such registration,
which Registration Statement shall comply as to form in all material respects
with the requirements of the applicable form and include all financial
statements required by the SEC to be filed therewith, and the Company shall use
its best efforts, consistent with its obligations under Section 2.7 hereof and
applicable law, to cause such Registration Statement to become effective within
120 days after receipt of a request to register Registrable Securities;
PROVIDED, that the Company may discontinue any registration of

                                       13
<Page>

its securities that are not Registrable Securities, and, under the circumstances
specified in Section 2.2, its securities that are Registrable Securities. Before
filing a Registration Statement or Prospectus or any amendments or supplements
thereto, or comparable statements under securities or blue sky laws of any
jurisdiction, the Company shall (i) provide Holders' Counsel and any other
Inspector (as defined below) with an adequate and appropriate opportunity to
participate in the preparation of such Registration Statement and each
Prospectus included therein (and each amendment or supplement thereto or
comparable statement) to be filed with the SEC, which documents shall be subject
to the review and comment of Holders' Counsel, and (ii) not file any such
Registration Statement or Prospectus (or amendment or supplement thereto or
comparable statement) with the SEC to which Holder's Counsel, any selling Holder
or any other Inspector shall have reasonably objected on the grounds that such
filing does not comply in all material respects with the requirements of the
Securities Act or of the rules or regulations thereunder;

                      (b)   prepare and file with the SEC such amendments and
supplements to such Registration Statement and the Prospectus used in connection
therewith as may be necessary (i) to keep such Registration Statement effective,
and (ii) to comply with the provisions of the Securities Act with respect to the
disposition of all Registrable Securities covered by such Registration
Statement, in each case until such time as all of such Registrable Securities
have been disposed of in accordance with the intended methods of disposition by
the seller(s) thereof set forth in such Registration Statement;

                      (c)  furnish, without charge, to each selling Holder of
such Registrable Securities and each Underwriter, if any, of the securities
covered by such Registration Statement, such number of copies of such
Registration Statement, each amendment and supplement thereto (in each case
including all exhibits), and the Prospectus included in such Registration
Statement (including each preliminary Prospectus) in conformity with the
requirements of the Securities Act, and other documents, as such selling Holder
and Underwriter may reasonably request in order to facilitate the public sale or
other disposition of the Registrable Securities owned by such selling Holder
(the Company hereby consenting to the use in accordance with applicable law of
each such Registration Statement (or amendment or post-effective amendment
thereto) and each such Prospectus (or preliminary prospectus or supplement
thereto) by each such selling Holder of Registrable Securities and the
Underwriters, if any, in connection with the offering and sale of the
Registrable Securities covered by such Registration Statement or Prospectus);

                      (d)  prior to any public offering of Registrable
Securities, use its best efforts to register or qualify all Registrable
Securities and other securities covered by such Registration Statement under
such other securities or blue sky laws of such jurisdictions as any selling
Holder of Registrable Securities covered by such Registration Statement or the
sole or lead managing Underwriter, if any, may reasonably request to enable such
selling Holder to consummate the disposition in such jurisdictions of the
Registrable Securities owned by such selling Holder and to continue such
registration or qualification in effect in each such jurisdiction for as long as
such Registration Statement remains in effect (including through new filings or
amendments or renewals), and do any and all other acts and things which may be
necessary or advisable to enable any such selling Holder to consummate the
disposition in such jurisdictions of the Registrable Securities owned by such
selling Holder;

                                       14
<Page>

                      (e)  use its best efforts to obtain all other approvals,
consents, exemptions or authorizations from such governmental agencies or
authorities as may be necessary to enable the selling Holders of such
Registrable Securities to consummate the disposition of such Registrable
Securities;

                      (f)  notify Holders' Counsel, each Holder of Registrable
Securities covered by such Registration Statement and the sole or lead managing
Underwriter, if any: (i) when the Registration Statement, any pre-effective
amendment, the Prospectus or any prospectus supplement related thereto or
post-effective amendment to the Registration Statement has been filed and, with
respect to the Registration Statement or any post-effective amendment, when the
same has become effective, (ii) of any request by the SEC or any state
securities or blue sky authority for amendments or supplements to the
Registration Statement or the Prospectus related thereto or for additional
information, (iii) of the issuance by the SEC of any stop order suspending the
effectiveness of the Registration Statement or the initiation or threat of any
proceedings for that purpose, (iv) of the receipt by the Company of any
notification with respect to the suspension of the qualification of any
Registrable Securities for sale under the securities or blue sky laws of any
jurisdiction or the initiation of any proceeding for such purpose, (v) of the
existence of any fact of which the Company becomes aware or the happening of any
event which results in (A) the Registration Statement containing an untrue
statement of a material fact or omitting to state a material fact required to be
stated therein or necessary to make any statements therein not misleading or (B)
the Prospectus included in such Registration Statement containing an untrue
statement of a material fact or omitting to state a material fact required to be
stated therein or necessary to make any statements therein, in the light of the
circumstances under which they were made, not misleading, (vi) if at any time
the representations and warranties contained in any underwriting agreement in
respect of such offering cease to be true and correct in all material respects,
and (vii) of the Company's reasonable determination that a post-effective
amendment to a Registration Statement would be appropriate or that there exists
circumstances not yet disclosed to the public which make further sales under
such Registration Statement inadvisable pending such disclosure and
post-effective amendment; and, if the notification relates to an event described
in any of the clauses (ii) through (vii) of this Section 4.1(f), the Company
shall promptly prepare a supplement or post-effective amendment to such
Registration Statement or related Prospectus or any document incorporated
therein by reference or file any other required document so that (1) such
Registration Statement shall not contain any untrue statement of a material fact
or omit to state a material fact required to be stated therein or necessary to
make the statements therein not misleading and (2) as thereafter delivered to
the purchasers of the Registrable Securities being sold thereunder, such
Prospectus shall not include an untrue statement of a material fact or omit to
state a material fact required to be stated therein or necessary to make the
statements therein in the light of the circumstances under which they were made
not misleading (and shall furnish to each such Holder and each Underwriter, if
any, a reasonable number of copies of such Prospectus so supplemented or
amended); and if the notification relates to an event described in clause (iii)
of this Section 4.1(f), the Company shall take all reasonable action required to
prevent the entry of such stop order or to remove it if entered;

                      (g)  make available for inspection by any selling Holder
of Registrable Securities, any sole or lead managing Underwriter participating
in any disposition pursuant to such Registration Statement, Holders' Counsel and
any attorney, accountant or other

                                       15
<Page>

agent retained by any such seller or any Underwriter (each, an "INSPECTOR" and,
collectively, the "INSPECTORS"), all financial and other records, pertinent
corporate documents and properties of the Company and any subsidiaries thereof
as may be in existence at such time (collectively, the "RECORDS") as shall be
necessary, in the opinion of such Holders' and such Underwriters' respective
counsel, to enable them to exercise their due diligence responsibility and to
conduct a reasonable investigation within the meaning of the Securities Act, and
cause the Company's and any subsidiaries' officers, directors and employees, and
the independent public accountants of the Company, to supply all information
reasonably requested by any such Inspectors in connection with such Registration
Statement;

                      (h)  obtain an opinion from the Company's counsel and a
"cold comfort" letter from the Company's independent public accountants who have
certified the Company's financial statements included or incorporated by
reference in such Registration Statement, in each case dated the effective date
of such Registration Statement (and if such registration involves an
Underwritten Offering, dated the date of the closing under the underwriting
agreement), in customary form and covering such matters as are customarily
covered by such opinions and "cold comfort" letters delivered to underwriters in
underwritten public offerings, which opinion and letter shall be reasonably
satisfactory to the sole or lead managing Underwriter, if any, and to the
Majority Holders of the Registration, and furnish to each Holder participating
in the offering and to each Underwriter, if any, a copy of such opinion and
letter addressed to such Holder (in the case of the opinion) and Underwriter (in
the case of the opinion and the "cold comfort" letter);

                      (i)  provide a CUSIP number for all Registrable Securities
and provide and cause to be maintained a transfer agent and registrar for all
such Registrable Securities covered by such Registration Statement not later
than the effectiveness of such Registration Statement;

                      (j)  otherwise use its best efforts to comply with all
applicable rules and regulations of the SEC and any other governmental agency or
authority having jurisdiction over the offering, and make available to its
security holders, as soon as reasonably practicable but no later than 90 days
after the end of any 12-month period, an earnings statement (i) commencing at
the end of any month in which Registrable Securities are sold to Underwriters in
an Underwritten Offering and (ii) commencing with the first day of the Company's
calendar month next succeeding each sale of Registrable Securities after the
effective date of a Registration Statement, which statement shall cover such
12-month periods, in a manner which satisfies the provisions of Section 11(a) of
the Securities Act and Rule 158 thereunder;

                      (k)  if so requested by the Majority Holders of the
Registration, use its best efforts to cause all such Registrable Securities to
be (i) duly included for quotation on the Nasdaq Stock Market's National Market
(the "NASDAQ NATIONAL MARKET") or listed on the principal national securities
exchange on which the Company's similar securities are then listed, if
applicable, or (ii) if securities of the Company are not at the time included on
the Nasdaq National Market or listed on any national securities exchange (or if
the listing of Registrable Securities is not permitted under the rules of each
national securities exchange on which the Company's securities are then listed),
on the National Nasdaq Market or a national securities exchange designated by
the Majority Holders of the Registration;

                                       16
<Page>

                      (l)  enter into and perform customary agreements
(including, if applicable, an underwriting agreement in customary form) and
provide officers' certificates and other customary closing documents;

                      (m)  cooperate with each selling Holder of Registrable
Securities and each Underwriter participating in the disposition of such
Registrable Securities and their respective counsel in connection with any
filings required to be made with the NASD and make reasonably available its
employees and personnel and otherwise provide reasonable assistance to the
Underwriters (taking into account the needs of the Company's businesses and the
requirements of the marketing process) in the marketing of Registrable
Securities in any Underwritten Offering;

                      (n)  cooperate with the selling Holders of Registrable
Securities and the sole or lead managing Underwriter, if any, to facilitate the
timely preparation and delivery of certificates not bearing any restrictive
legends representing the Registrable Securities to be sold, and cause such
Registrable Securities to be issued in such denominations and registered in such
names in accordance with the underwriting agreement prior to any sale of
Registrable Securities to the Underwriters or, if not an Underwritten Offering,
in accordance with the instructions of the selling Holders of Registrable
Securities at least three business days prior to any sale of Registrable
Securities;

                      (o)  keep each selling Holder of Registrable Securities
advised in writing as to the initiation and progress of any registration under
Section 2 hereunder;

                      (p)  furnish to each Holder participating in the offering
and the sole or lead managing Underwriter, if any, without charge, at least one
manually-signed copy of the Registration Statement and any post-effective
amendments thereto, including financial statements and schedules, all documents
incorporated therein by reference and all exhibits (including those deemed to be
incorporated by reference);

                      (q)  if requested by the sole or lead managing
Underwriter, if any, or any selling Holder of Registrable Securities, promptly
incorporate in a prospectus supplement or post-effective amendment such
information concerning such Holder of Registrable Securities, the Underwriters
or the intended method of distribution as the sole or lead managing Underwriter
or the selling Holder of Registrable Securities reasonably requests to be
included therein and as is appropriate in the reasonable judgment of the
Company, including, without limitation, information with respect to the number
of shares of the Registrable Securities being sold to the Underwriters, the
purchase price being paid therefor by such Underwriters and with respect to any
other terms of the Underwritten Offering of the Registrable Securities to be
sold in such offering; make all required filings of such Prospectus supplement
or post-effective amendment as soon as notified of the matters to be
incorporated in such Prospectus supplement or post-effective amendment; and
supplement or make amendments to any Registration Statement if requested by the
sole or lead managing Underwriter of such Registrable Securities; and

                                       17
<Page>

                      (r)  use its best efforts to take all other steps
necessary to expedite or facilitate the registration and disposition of the
Registrable Securities contemplated hereby.

               4.2.   SELLER INFORMATION. The Company may require each selling
Holder of Registrable Securities as to which any registration is being effected
to furnish to the Company such information regarding such seller and the
disposition of such securities as the Company may from time to time reasonably
request in writing; PROVIDED, HOWEVER, that such information shall be used only
in connection with such Registration. If any Registration Statement or
comparable statement under "blue sky" laws refers to any Holder by name or
otherwise as the Holder of any securities of the Company, then such Holder shall
have the right to require (i) the insertion therein of language, in form and
substance satisfactory to such Holder and the Company, to the effect that the
holding by such Holder of such securities is not to be construed as a
recommendation by such Holder of the investment quality of the Company's
securities covered thereby and that such holding does not imply that such Holder
will assist in meeting any future financial requirements of the Company and (ii)
in the event that such reference to such Holder by name or otherwise is not in
the judgment of the Company, as advised by counsel, required by the Securities
Act or any similar federal statute or any state "blue sky" or securities law
then in force, the deletion of the reference to such Holder.

               4.3.   NOTICE TO DISCONTINUE. Each Holder of Registrable
Securities agrees by acquisition of such Registrable Securities that, (a) upon
receipt of any notice from the Company of the happening of any event of the kind
described in Section 4.1(f)(ii) through 4.1(f)(vii), such Holder shall forthwith
discontinue disposition of Registrable Securities pursuant to the Registration
Statement covering such Registrable Securities until such Holder's receipt of
the copies of the supplemented or amended prospectus contemplated by Section
4.1(f) and, (b) if so directed by the Company, such Holder shall deliver to the
Company (at the Company's expense) all copies, other than permanent file copies,
then in such Holder's possession, of the Prospectus covering such Registrable
Securities which is current at the time of receipt of such notice. If the
Company shall give any such notice, the Company shall extend the period during
which such Registration Statement shall be maintained effective pursuant to this
Agreement (including, without limitation, the period referred to in Section
4.1(b)) by the number of days during the period from and including the date of
the giving of such notice pursuant to Section 4.1(f) to and including the date
when the Holder shall have received the copies of the supplemented or amended
prospectus contemplated by and meeting the requirements of Section 4.1(f).

          5. INDEMNIFICATION; CONTRIBUTION.

               5.1.   INDEMNIFICATION BY THE COMPANY. The Company agrees to
indemnify and hold harmless, to the fullest extent permitted by law, each Holder
of Registrable Securities, its officers, directors, partners, members,
shareholders, employees, Affiliates, advisers, attorneys and agents
(collectively, "AGENTS") and each Person who controls such Holder (within the
meaning of the Securities Act) and its Agents with respect to each registration
which has been effected pursuant to this Agreement, against any and all losses,
claims, damages or liabilities, joint or several, actions or proceedings
(whether commenced or threatened) in respect thereof, and expenses (as incurred
or suffered and including, but not limited to, any and all

                                       18
<Page>

expenses incurred in investigating, preparing or defending any litigation or
proceeding, whether commenced or threatened, and the reasonable fees,
disbursements and other charges of legal counsel) in respect thereof
(collectively, "CLAIMS"), insofar as such Claims arise out of or are based upon
any untrue or alleged untrue statement of a material fact contained in any
Registration Statement or Prospectus (including any preliminary, final or
summary prospectus and any amendment or supplement thereto) related to any such
registration or any omission or alleged omission to state a material fact
required to be stated therein or necessary to make the statements therein not
misleading, or any violation by the Company of the Securities Act or any rule or
regulation thereunder applicable to the Company and relating to action or
inaction required of the Company in connection with any such registration, or
any qualification or compliance incident thereto; PROVIDED, HOWEVER, that the
Company will not be liable in any such case to the extent that any such Claims
arise out of or are based upon any untrue statement or alleged untrue statement
of a material fact or omission or alleged omission of a material fact so made in
reliance upon and in conformity with written information furnished to the
Company by a Holder expressly for use therein. The Company shall also indemnify
any Underwriters of the Registrable Securities, their Agents and each Person who
controls any such Underwriter (within the meaning of the Securities Act) to the
same extent as provided above with respect to the indemnification of the Holders
of Registrable Securities. Such indemnity shall remain in full force and effect
regardless of any investigation made by or on behalf of any Person who may be
entitled to indemnification pursuant to this Section 5 and shall survive the
transfer of securities by such Holder or Underwriter.

               5.2.   INDEMNIFICATION BY HOLDERS. Each Holder, if Registrable
Securities held by it are included in the securities as to which a registration
is being effected, agrees to, severally and not jointly, indemnify and hold
harmless, to the fullest extent permitted by law, the Company, its directors and
officers, each other Person who participates as an Underwriter in the offering
or sale of such securities and its Agents and each Person who controls the
Company (within the meaning of either Section 15 of the Securities Act of
Section 20 of the Exchange Act) against any and all Claims, insofar as such
Claims arise out of or are based upon any untrue or alleged untrue statement of
a material fact contained in any Registration Statement or Prospectus (including
any preliminary, final or summary prospectus and any amendment or supplement
thereto) related to such registration, or any omission or alleged omission to
state therein a material fact required to be stated therein or necessary to make
the statements therein not misleading, to the extent, but only to the extent,
that such untrue statement or alleged untrue statement or omission or alleged
omission was made in reliance upon and in conformity with written information
furnished to the Company by a Holder expressly for use therein; PROVIDED,
HOWEVER, that the aggregate amount which any such Holder shall be required to
pay pursuant to this Section 5.2 shall in no event be greater than the amount of
the net proceeds received by such Holder upon the sale of the Registrable
Securities pursuant to the Registration Statement giving rise to such Claims
less all amounts previously paid by such Holder with respect to any such Claims.
Such indemnity shall remain in full force and effect regardless of any
investigation made by or on behalf of any Person who may be entitled to
indemnification pursuant to this Section 5 and shall survive the transfer of
securities by such Holder or Underwriter.

               5.3.   CONDUCT OF INDEMNIFICATION PROCEEDINGS. Promptly after
receipt by an indemnified party of notice of any Claim or the commencement of
any action or proceeding involving a Claim under this Section 5, such
indemnified party shall, if a claim in

                                       19
<Page>

respect thereof is to be made against the indemnifying party pursuant to Section
5, (a) notify the indemnifying party in writing of the Claim or the commencement
of such action or proceeding; PROVIDED, that the failure of any indemnified
party to provide such notice shall not relieve the indemnifying party of its
obligations under this Section 5, except to the extent the indemnifying party is
materially and actually prejudiced thereby and shall not relieve the
indemnifying party from any liability which it may have to any indemnified party
otherwise than under this Section 5, and (b) permit such indemnifying party to
assume the defense of such claim with counsel reasonably satisfactory to the
indemnified party; PROVIDED, HOWEVER, that any indemnified party shall have the
right to employ separate counsel and to participate in the defense of such
claim, but the fees and expenses of such counsel shall be at the expense of such
indemnified party unless (i) the indemnifying party has agreed in writing to pay
such fees and expenses, (ii) the indemnifying party shall have failed to assume
the defense of such claim and employ counsel reasonably satisfactory to such
indemnified party within 20 days after receiving notice from such indemnified
party that the indemnified party believes it has failed to do so, or (C) in the
reasonable judgment of any such indemnified party, based upon advice of counsel,
a conflict of interest shall exist between such indemnified party and the
indemnifying party with respect to such claims; it being understood, however,
that the indemnifying party shall not, in connection with any one such action or
separate but substantially similar or related actions in the same jurisdiction
arising out of the same general allegations or circumstances, be liable for the
reasonable fees and expenses of more than one separate firm of attorneys (in
addition to no more than one firm of local counsel) at any time for all such
indemnified parties. No indemnifying party shall be liable for any settlement of
any such claim or action effected without its written consent, which consent
shall not be unreasonably withheld. No indemnifying party shall, without the
consent of the indemnified party, which consent shall not be unreasonable
withheld, consent to entry of any judgment or enter into any settlement of any
claim or action in respect of which indemnification or contribution may be
sought hereunder, unless such settlement, (x) includes an unconditional release
of the indemnified party from all liability arising out of such action or claim,
(y) does not include a statement as to or an admission of fault, culpability or
a failure to act, by or on behalf of any indemnified party, and (z) does not
provide for any action on the part of any party other than the payment of money
damages which is to be paid in full by the indemnifying party.

               5.4.   CONTRIBUTION. If the indemnification provided for in
Section 5.1 or 5.2 from the indemnifying party for any reason is unavailable to
(other than by reason of exceptions provided therein), or is insufficient to
hold harmless an indemnified party hereunder in respect of any Claim, then the
indemnifying party, in lieu of indemnifying such indemnified party, shall
contribute to the amount paid or payable by such indemnified party as a result
of such Claim in such proportion as is appropriate to reflect the relative fault
of the indemnifying party, on the one hand, and the indemnified party, on the
other hand, in connection with the actions which resulted in such Claim, as well
as any other relevant equitable considerations. The relative fault of such
indemnifying party and indemnified party shall be determined by reference to,
among other things, whether any action in question, including any untrue or
alleged untrue statement of a material fact or omission or alleged omission to
state a material fact, has been made by, or relates to information supplied by,
such indemnifying party or indemnified party, and the parties' relative intent,
knowledge, access to information and opportunity to correct or prevent such
action. If, however, the foregoing allocation is not permitted by applicable
law, then each indemnifying party shall contribute to the amount paid or payable
by such indemnified

                                       20
<Page>

party in such proportion as is appropriate to reflect not only such relative
faults but also the relative benefits of the indemnifying party and the
indemnified party as well as any other relevant equitable considerations.

               5.5.   INDEMNIFICATION PAYMENTS. The indemnification and
contribution required by this Section 5 shall be made by periodic payments of
the amount thereof during the course of any investigation or defense, as and
when bills are received or any expense, loss, damage or liability is incurred.

               5.6.   OTHER INDEMNIFICATION. Indemnification similar to that
specified in the preceding Sections 5.1 and 5.2 (with appropriate modifications)
shall be given by the Company and each selling Holder of Registrable Securities
with respect to any required registration or other qualification of securities
under any Federal or state law or regulation of any governmental authority,
other than the Securities Act. The indemnity agreements contained herein shall
be in addition to any other rights to indemnification or contribution which any
indemnified party may have pursuant to law or contract.

          6. GENERAL PROVISIONS REGARDING REGISTRATIONS.

               6.1.   ADJUSTMENTS AFFECTING REGISTRABLE SECURITIES. The Company
agrees that it shall not effect or permit to occur any combination or
subdivision of shares which would adversely affect the ability of the Holder of
any Registrable Securities to include such Registrable Securities in any
registration contemplated by this Agreement or the marketability of such
Registrable Securities in any such registration.

               6.2.   REGISTRATION RIGHTS TO OTHERS. The Company represents and
warrants that it is not currently a party to any agreement with respect to its
securities granting registration rights to Persons. If the Company shall at any
time hereafter provide to any holder of any securities of the Company rights
with respect to the registration of such securities under the Securities Act,
(i) such rights shall not be in conflict with or adversely affect any of the
rights provided in this Agreement to the Holders and (ii) if such rights are
provided on terms or conditions more favorable to such holder than the terms and
conditions provided in this Agreement, the Company shall provide (by way of
amendment to this Agreement or otherwise) such more favorable terms or
conditions to the Holders.

               6.3.   AVAILABILITY OF INFORMATION; RULE 144; RULE 144A; OTHER
EXEMPTIONS. The Company covenants that it shall timely file any reports required
to be filed by it under the Securities Act or the Exchange Act (including, but
not limited to, the reports under Sections 13 and 15(d) of the Exchange Act
referred to in subparagraph (c) of Rule 144 under the Securities Act), and that
it shall take such further action as any Holder of Registrable Securities may
reasonably request, all to the extent required from time to time to enable such
Holder to sell Registrable Securities without registration under the Securities
Act within the limitation of the exemptions provided by (i) Rule 144 and Rule
144A under the Securities Act, as such rules may be amended from time to time,
or (ii) any other rule or regulation now existing or hereafter adopted by the
SEC. Upon the request of any Holder of Registrable Securities, the Company shall
deliver to such Holder a written statement as to whether it has complied with
such requirements.

                                       21
<Page>

          7. PROVISIONS APPLICABLE TO SECURITYHOLDERS.

               7.1.   GENERAL RESTRICTION. Prior to the earlier of (i) 270 days
after the exercise of all of the Warrants or (ii) December 31, 2009 (the period
ending on the earlier of such dates being the referred to below as the "Co-Sale
Period"), McKim may not, directly or indirectly, sell, assign, transfer, pledge,
bequeath, hypothecate, mortgage, grant any proxy with respect to, or in any
other way encumber or otherwise dispose of ("CONVEY"), any shares of Common
Stock except pursuant to the provisions of this Article 7.

               7.2.   RIGHT OF CO-SALE. (a) If during the Co-Sale Period, McKim
desires to Convey shares of Common Stock to any Person (the "PURCHASER"), each
Holder shall have the right to require, as a condition to such Conveyance, that
the Purchaser purchase from such Holder at the same price and on the same terms
and conditions as involved in such sale or disposition by McKim (the "PURCHASE
OFFER") the number of shares of Common Stock owned by such Holder equal to the
aggregate number of shares of Common Stock proposed to be purchased by the
Purchaser from McKim multiplied by a fraction, the numerator of which is the
number of shares of Common Stock held of record by such Holder and the
denominator of which is the aggregate number of shares of Common Stock held of
record by McKim and the Holders. The amount of shares of Common Stock that each
Holder is entitled to sell under this Section 7.2 shall be referred to as its
"PRO RATA SHARE". McKim shall deliver to each Holder not more than 60 days and
not less than 30 days prior to the proposed Conveyance to the Purchaser a copy
of the Purchase Offer, if in writing, and a description of all other material
terms and conditions of the Purchase Offer. Within 25 days after receipt of the
Purchase Offer, a Holder shall give notice to McKim of its intent to sell all or
a portion of its Pro Rata Share. In the event that a Holder shall elect to
participate in any such sale or disposition, such Holder shall communicate in
writing such election to participate to McKim, which communication shall be
delivered to McKim pursuant to Section 8.2 hereof, and the number of shares of
Common Stock to be Conveyed by McKim to the Purchaser shall be reduced
accordingly.

                      (b)  McKim and each participating Holder may, up to and
including 90 days after but not until at least 60 days after McKim's delivery of
the notice of the Purchase Offer to the Holders, Convey any or all of their
shares of Common Stock to the Purchaser, in quantities and on terms and
conditions no more favorable in any material respect to those specified in the
Purchase Offer or otherwise disclosed to the Holders, and the Holders shall not
have the right to require that the Purchaser purchase any of their shares of
Common Stock as to which they did not exercise their co-sale rights hereunder.
If such sale is not consummated by the expiration of such 90 day period, the
restrictions provided for herein shall again become effective, and no Conveyance
of such shares of Common Stock may be made thereafter by McKim without again
complying with the requirements of this Section 7.2.

                      (c)  The closing of any sale of the shares of Common Stock
by the Holders and/or McKim pursuant to this Section 7.2 shall be held at the
Company's principal office at 10:00 a.m., local time, no later than 30 days
after the dates of expiration of the right to sell referred to in Sections
7.2(a) and 7.2(b) hereof, or at such other time and place as the parties to the
transaction may agree. At such closing, each Holder (if it has elected to
participate in accordance with this Section 7.2) and/or McKim shall Convey all
the shares of Common Stock purchased by the Purchaser pursuant to this Section
7.2 free and clear of any Encumbrances

                                       22
<Page>

(other than restrictions imposed by the organizational documents of the Company,
including without limitation, this Agreement, and pursuant to applicable federal
and state securities laws), and each such Holder and/or McKim shall so represent
and warrant, and further represent and warrant that it is the record and
beneficial owner of such shares of Common Stock. The Purchaser shall deliver at
such closing, in cash by wire transfer of immediately available funds, payment
in full to the each of the Holders and/or McKim for its respective portion of
such shares of Common Stock sold.

                      (d)  The election by a Holder not to exercise its rights
under this Section 7.2 in any one instance shall not affect the rights of that
Holder as to any subsequent proposed Conveyance by McKim. Any Conveyance by
McKim of any of its shares of Common Stock without first giving the Holders the
rights described in this Section 7.2 shall be void and of no force or effect.

               7.3.   PERMITTED TRANSFERS. Subject to the final proviso of this
paragraph, the provisions of Section 7.1 or 7.2 shall not apply to the
Conveyance of Common Stock by McKim (a) in a public offering registered under
the Securities Act; PROVIDED; that the Holders shall have had the opportunity to
participate in such offering, without limitation (except as expressly provided
in Section 2 hereof) on the number of Registrable Securities covered thereby, in
accordance with Section 2 hereof, (b) in a sale pursuant to Rule 144 of the
Securities Act, (c) pursuant to a bona fide pledge of the Common Stock to a
nationally recognized financial institution as security for a bona fide
financing arrangement by McKim and (d) to any one or more persons or entities
each of which is a "Permitted Holder" as such term is defined in the Certificate
of Vote in respect of the Series C Preferred Stock as in effect on September 10,
2002 (collectively "PERMITTED FAMILY TRANSFEREES"); PROVIDED, HOWEVER, that such
Permitted Family Transferee(s) shall take such shares of Common Stock subject to
and be fully bound by this Agreement with the same effect as if it were a party
hereto and shall execute and deliver to the Company and each Holder an
instrument of accession and such additional documentation as the Company's Board
of Directors and the Holders may reasonably require to bind such Permitted
Family Transferee in the same manner that McKim is bound under this Agreement,
and references herein to McKim shall be deemed to include any such Permitted
Family Transferee(s).

          8. GENERAL.

               8.1.   AMENDMENTS AND WAIVERS. The provisions of this Agreement,
including the provisions of this sentence, may not be amended, modified,
supplemented or terminated, and waivers or consents to departures from the
provisions hereof may not be given, without the written consent of the Company
and the Majority Holders and if adverse to McKim, McKim; PROVIDED, HOWEVER, that
no such amendment, modification, supplement, waiver or consent to departure
shall reduce the aforesaid percentage of Registrable Securities without the
written consent of all of the Holders of Registrable Securities and no
amendment, modification supplement, waiver or consent that adversely affects the
rights of a particular Holder (as opposed to the Holders generally) shall be
made or given without the written consent of such particular Holder; and
PROVIDED FURTHER, that nothing herein shall prohibit any amendment,
modification, supplement, termination, waiver or consent to departure the effect
of which is limited only to those Holders who have agreed to such amendment,
modification, supplement, termination, waiver or consent to departure.

                                       23
<Page>

               8.2.   NOTICES. All notices and other communications provided for
or permitted hereunder shall be made in writing by hand delivery, telecopier,
any courier guaranteeing overnight delivery or first class registered or
certified mail, return receipt requested, postage prepaid, addressed to the
applicable party at the address set forth below or such other address as may
hereafter be designated in writing by such party to the other parties in
accordance with the provisions of this Section:

          If to the Company:  Clean Harbors, Inc.
                              1501 Washington Street
                              Braintree, MA 02185
                              Attn: Chief Financial Officer
                              Fax No. (781) 848-1632

          with copies to:     Davis, Malm & D'Agostine, P.C.
                              One Boston Place
                              Boston, MA 02108
                              Attn: C. Michael Malm
                              Fax No. (617) 523-6215

          If to McKim:        Alan S. McKim
                              c/o Clean Harbors, Inc.
                              1501 Washington Street
                              Braintree, MA 02185
                              Fax No. (781) 848-1632

          with copies to:     Davis, Malm & D'Agostine, P.C.
                              One Boston Place
                              Boston, MA 02108
                              Attn: C. Michael Malm
                              Fax No. (617) 523-6215

          If to a Holder, to its address and facsimile set forth on the Schedule
of Holders attached hereto, with copies to such Holder's representatives as set
forth on the Schedule of Holders, or to such other address and/or facsimile
number and/or to the attention of such other person as the recipient party has
specified by written notice given to each other party five (5) days prior to the
effectiveness of such change. All such notices and communications (and
deliveries) shall be deemed to have been duly given: at the time delivered by
hand, if personally delivered; when receipt is acknowledged, if telecopied; on
the next business day, if timely delivered to a courier guaranteeing overnight
delivery; and five days after being deposited in the mail, if sent first class
or certified mail, return receipt requested, postage prepaid.

               8.3.   SUCCESSORS AND ASSIGNS. This Agreement shall inure to the
benefit of and be binding upon the parties hereto and their respective heirs,
successors and permitted assigns (including any permitted transferee of
Registrable Securities or the Warrants). Any Holder may assign to any transferee
of its Warrants or Registrable Securities (other than a transferee that acquires
such Registrable Securities or Warrants in a registered public offering or

                                       24
<Page>

pursuant to a sale under Rule 144 of the Securities Act (or any successor
rule)), its rights and obligations under this Agreement; PROVIDED, HOWEVER, if
any transferee shall take and hold the Warrants or Registrable Securities, such
transferee shall promptly notify the Company and by taking and holding such
Registrable Securities or the Warrants such transferee shall automatically be
entitled to receive the benefits of and be conclusively deemed to have agreed to
be bound by and to perform all of the terms and provisions of this Agreement as
if it were a party hereto (and shall, for all purposes, be deemed a Holder under
this Agreement). If the Company shall so request any heir, successor or
permitted assign (including any permitted transferee) wishing to avail itself of
the benefits of this Agreement shall agree in writing to acquire and hold the
Registrable Securities or the Warrants subject to all of the terms hereof. For
purposes of this Agreement, "successor" for any entity other than a natural
person shall mean a successor to such entity as a result of such entity's
merger, consolidation, sale of substantially all of its assets, or similar
transaction. Except as provided above or otherwise permitted by this Agreement,
neither this Agreement nor any right, remedy, obligation or liability arising
hereunder or by reason hereof shall be assignable by any Holder, McKim or by the
Company without the consent of the other parties hereto.

               8.4.   COUNTERPARTS. This Agreement may be executed in two or
more counterparts, each of which, when so executed and delivered, shall be
deemed to be an original, but all of which counterparts, taken together, shall
constitute one and the same instrument.

               8.5.   DESCRIPTIVE HEADINGS, ETC. The headings in this Agreement
are for convenience of reference only and shall not limit or otherwise affect
the meaning of terms contained herein. Unless the context of this Agreement
otherwise requires: (a) words of any gender shall be deemed to include each
other gender; (b) words using the singular or plural number shall also include
the plural or singular number, respectively; (c) the words "hereof", "herein"
and "hereunder" and words of similar import when used in this Agreement shall
refer to this Agreement as a whole and not to any particular provision of this
Agreement, and Section and paragraph references are to the Sections and
paragraphs of this Agreement unless otherwise specified; (d) the word
"including" and words of similar import when used in this Agreement shall mean
"including, without limitation," unless otherwise specified; (e) "or" is not
exclusive; and (f) provisions apply to successive events and transactions.

               8.6.   SEVERABILITY. In the event that any one or more of the
provisions, paragraphs, words, clauses, phrases or sentences contained herein,
or the application thereof in any circumstances, is held invalid, illegal or
unenforceable in any respect for any reason, the validity, legality and
enforceability of any such provision, paragraph, word, clause, phrase or
sentence in every other respect and of the other remaining provisions,
paragraphs, words, clauses, phrases or sentences hereof shall not be in any way
impaired, it being intended that all rights, powers and privileges of the
parties hereto shall be enforceable to the fullest extent permitted by law.

               8.7.   CHOICE OF LAW AND VENUE; JURY TRIAL WAIVER. THE VALIDITY
OF THIS AGREEMENT, THE CONSTRUCTION, INTERPRETATION, AND ENFORCEMENT HEREOF, AND
THE RIGHTS OF THE PARTIES HERETO WITH RESPECT TO ALL MATTERS ARISING HEREUNDER
OR RELATED HERETO SHALL BE DETERMINED UNDER, GOVERNED BY, AND

                                       25
<Page>

CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

          THE PARTIES AGREE THAT ALL ACTIONS OR PROCEEDINGS ARISING IN
CONNECTION WITH THIS AGREEMENT SHALL BE TRIED AND LITIGATED ONLY IN THE STATE
AND FEDERAL COURTS LOCATED IN THE COUNTY OF NEW YORK, STATE OF NEW YORK. THE
COMPANY, MCKIM AND THE INITIAL HOLDERS WAIVE, TO THE EXTENT PERMITTED UNDER
APPLICABLE LAW, ANY RIGHT EACH MAY HAVE TO ASSERT THE DOCTRINE OF FORUM NON
CONVENIENS OR TO OBJECT TO VENUE TO THE EXTENT ANY PROCEEDING IS BROUGHT IN
ACCORDANCE WITH THIS SECTION 8.7.

          THE COMPANY, MCKIM AND THE INITIAL HOLDERS HEREBY WAIVE THEIR
RESPECTIVE RIGHTS TO A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION BASED UPON OR
ARISING OUT OF THIS AGREEMENT OR ANY OF THE TRANSACTIONS CONTEMPLATED HEREIN,
INCLUDING CONTRACT CLAIMS, TORT CLAIMS, BREACH OF DUTY CLAIMS, AND ALL OTHER
COMMON LAW OR STATUTORY CLAIMS. EACH OF THE COMPANY, MCKIM AND THE INITIAL
HOLDERS REPRESENT THAT EACH HAS REVIEWED THIS WAIVER AND EACH KNOWINGLY AND
VOLUNTARILY WAIVES ITS JURY TRIAL RIGHTS FOLLOWING CONSULTATION WITH LEGAL
COUNSEL. IN THE EVENT OF LITIGATION, A COPY OF THIS AGREEMENT MAY BE FILED AS A
WRITTEN CONSENT TO A TRIAL BY THE COURT.

               8.8.   REMEDIES; SPECIFIC PERFORMANCE. The parties hereto
acknowledge that money damages would not be an adequate remedy at law if any
party fails to perform in any material respect any of its obligations hereunder,
and accordingly agree that each party, in addition to any other remedy to which
it may be entitled at law or in equity, shall be entitled to seek to compel
specific performance of the obligations of any other party under this Agreement,
without the posting of any bond, in accordance with the terms and conditions of
this Agreement in any court specified in Section 8.7 hereof, and if any action
should be brought in equity to enforce any of the provisions of this Agreement,
none of the parties hereto shall raise the defense that there is an adequate
remedy at law. Except as otherwise provided by law, a delay or omission by a
party hereto in exercising any right or remedy accruing upon any such breach
shall not impair the right or remedy or constitute a waiver of or acquiescence
in any such breach. No remedy shall be exclusive of any other remedy. All
available remedies shall be cumulative.

               8.9.   ENTIRE AGREEMENT. This Agreement, the Warrants and the
Redemption Agreement (collectively, the "OTHER AGREEMENTS") are intended by the
parties as a final expression of their agreement and intended to be a complete
and exclusive statement of the agreement and understanding of the parties hereto
in respect of the subject matter contained herein. There are no restrictions,
promises, representations, warranties, covenants or undertakings relating to
such subject matter, other than those set forth or referred to herein or in the
Other Agreements. This Agreement and the Other Agreements supersede all prior
agreements and understandings between the Company and the other parties to this
Agreement with respect to such subject matter.

                                       26
<Page>

               8.10.  FURTHER ASSURANCES. Each party hereto shall do and perform
or cause to be done and performed all such further acts and things and shall
execute and deliver all such other agreements, certificates, instruments and
documents as any other party hereto reasonably may request in order to carry out
the intent and accomplish the purposes of this Agreement and the consummation of
the transactions contemplated hereby.

               8.11.  CONSTRUCTION. Each of the Company, McKim and the Initial
Holders acknowledge that it has had the benefit of legal counsel of its own
choice and has been afforded an opportunity to review this Agreement with its
legal counsel and that this Agreement shall be construed as if jointly drafted
by the Company, McKim and the Initial Holders.

               8.12.  NO INCONSISTENT AGREEMENT. Neither the Company nor McKim
will hereafter enter into any agreement which is inconsistent with the rights
granted to the Holders in this Agreement.

               8.13.  COSTS AND ATTORNEYS' FEES. In the event that any action,
suit or other proceeding is instituted concerning or arising out of this
Agreement, the Company, McKim and the Initial Holders agree that the prevailing
party shall recover from the non-prevailing party all of such prevailing party's
costs and reasonable attorneys' fees incurred in each and every such action,
suit or other proceeding, including any and all appeals or petitions therefrom.

   [Remainder of this page intentionally left blank. Signature page follows.]

                                       27
<Page>

          IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be duly executed as of the date first written above.


                                   THE COMPANY

                                   CLEAN HARBORS, INC.


                                   By:
                                       ---------------------------
                                       Name:
                                       Title

<Page>

                                   INITIAL HOLDERS

                                   CERBERUS CH LLC

                                   By: Cerberus Partners, L.P.
                                       its Managing Member

                                   By: Cerberus Associates, L.L.C.
                                       its General Partner

                                   By:
                                       --------------------------------
                                       Name:
                                       Title:

<Page>

                                   OAK HILL SECURITIES FUND, L.P.

                                   By: Oak Hill Securities GenPar, L.P.
                                       its General Partner

                                   By: Oak Hill Securities MGP, Inc.
                                       its General Partner

                                   By:
                                       --------------------------------
                                       Name:
                                       Title:


                                   OAK HILL SECURITIES FUND II, L.P.

                                   By: Oak Hill Securities GenPar II, L.P.
                                       its General Partner

                                   By: Oak Hill Securities MGP II, Inc.
                                       its General Partner

                                   By:
                                       --------------------------------
                                       Name:
                                       Title:


                                   LERNER ENTERPRISES, L.P.

                                   By: Oak Hill Asset Management, Inc.
                                       As advisor and attorney-in-fact to
                                       Lerner Enterprises

                                   By:
                                       --------------------------------
                                       Name:
                                       Title:

<Page>

                                   P&PK FAMILY LTD. PARTNERSHIP

                                   By: Oak Hill Asset Management, Inc.
                                       As advisor and attorney-in-fact to
                                       P&PK Family Ltd. Partnership

                                   By:
                                       --------------------------------
                                       Name:
                                       Title:


                                   CARDINAL INVESTMENT PARTNERS I,
                                   L.P.

                                   By: As advisor and attorney-in-fact to
                                       Cardinal Investment Partners I, L.P.

                                   By: Oak Hill Advisors MGP, Inc.
                                       its General Partner

                                   By:
                                       --------------------------------
                                       Name:
                                       Title:

                                   BASSO HOLDINGS LTD.
                                   (f/k/a AIG DKR SoundShore Holdings Ltd.)


                                   By:
                                       --------------------------------
                                       Howard I. Fischer
                                       Authorized Signatory

<Page>

                                   MCKIM


                                   By:
                                       --------------------------------
                                       Name: Alan S. McKim

                                   Alan S. McKim's Children's Trust


                                   By:
                                       --------------------------------
                                       C. Michael Malm, Trustee

                                   By:
                                       --------------------------------
                                       Carol R. Cohen, Trustee

<Page>

                               SCHEDULE OF HOLDERS

<Table>
<Caption>
                 Holder Address                          Investor's Representatives' Address
              and Facsimile Number                              and Facsimile Number
-------------------------------------------------   ---------------------------------------------
<S>                                                 <C>
Cerberus CH LLC                                     Schulte Roth & Zabel LLP
450 Park Avenue, 28th Floor                         919 Third Avenue
New York, NY 10022                                  New York, NY  10022
Telephone: (212) 891-2100                           Attn: Stuart Freedman, Esq.
Facsimile: (212) 891-1540                           Telephone: (212) 756-2000
Attention: Daniel Wolf and Kevin Genda              Facsimile: (212) 593-5955

Oak Hill Securities Fund, L.P.                      Paul, Weiss, Rifkind, Wharton & Garrison
65 East 55th Street                                 1285 Avenue of the Americas
New York, New York 10022                            New York, NY 10019
Telephone: (212) 326-1552                           Telephone: (212) 373-3000
Facsimile: (212) 838-8411                           Facsimile: (212) 757-3990
Attention: William H. Bohnsack, Jr.                 Attention: Eric Goodison

Oak Hill Securities Fund II, L.P.                   Paul, Weiss, Rifkind, Wharton & Garrison
65 East 55th Street                                 1285 Avenue of the Americas
New York, New York 10022                            New York, NY 10019
Telephone: (212) 326-1552                           Telephone: (212) 373-3000
Facsimile: (212) 838-8411                           Facsimile: (212) 757-3990
Attention: William H. Bohnsack, Jr.                 Attention: Eric Goodison

Lerner Enterprises, L.P.                            Paul, Weiss, Rifkind, Wharton & Garrison
65 East 65th Street                                 1285 Avenue of the Americas
New York, New York 10022                            New York, NY 10019
Telephone: (212) 326-1552                           Telephone: (212) 373-3000
Facsimile: (212) 838-8411                           Facsimile: (212) 757-3990
Attention: William H. Bohnsack, Jr.                 Attention: Eric Goodison

P&PK Family Ltd. Partnership                        Paul, Weiss, Rifkind, Wharton & Garrison
65 East 55th Street                                 1285 Avenue of the Americas
New York, New York 10021                            New York, NY 10019
Telephone: (212) 326-1552                           Telephone: (212) 373-3000
Facsimile: (212) 838-8411                           Facsimile: (212) 757-3990
Attention: William H. Bohnsack, Jr.

Cardinal Investment Partners I, L.P.                Paul, Weiss, Rifkind, Wharton & Garrison
65 East 55th Street                                 1285 Avenue of the Americas
New York, New York 10021                            New York, NY 10019
Telephone: (212) 326-1552                           Telephone: (212) 373-3000
Facsimile: (212) 838-8411                           Facsimile: (212) 757-3990
Attention: William H. Bohnsack, Jr.                 Attention: Eric Goodison

Basso Holdings Ltd.                                 Basso Holdings Ltd.
c/o Basso Capital Management, L.P.                  c/o Basso Capital Management, L.P.
1266 East Main Street                               1266 East Main Street
Stamford, Connecticut 06902                         Stamford, Connecticut 06902
Telephone: (203) 352-6100                           Telephone: (203) 352-6100
Facsimile: (203) 352-6194                           Facsimile: (203) 352-6194
Attention: Howard I. Fischer                        Attention: Marc Seidenberg
</Table>

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                                    EXHIBIT A

                             [SEC NO-ACTION LETTER]