Exhibit 4.3


                          REGISTRATION RIGHTS AGREEMENT



                          dated as of October 16, 1998



                                      among



                          DLJ INVESTMENT PARTNERS, L.P.,

                                DLJ ESC II L.P.,

                          DLJ INVESTMENT FUNDING, INC.,

                  CREDIT SUISSE FIRST BOSTON (EUROPE) LIMITED,

                         CHASE EQUITY ASSOCIATES, L.P.,

                               ENVIROSYSTEMS CORP.

                                       and

                  ENVIRONMENTAL SYSTEMS PRODUCTS HOLDINGS INC.



                                TABLE OF CONTENTS


                                                                            Page
                                                                            ----

                                    ARTICLE 1
                                   DEFINITIONS
                                                                          
SECTION 1.01. Definitions......................................................1

                                    ARTICLE 2
                               REGISTRATION RIGHTS

SECTION 2.01. Rule 144A Matters, Initial Registration and Demand Registration..5
SECTION 2.02. Registration Procedures..........................................9
SECTION 2.03. Indemnification by the Issuer...................................12
SECTION 2.04. Indemnification by Participating Securityholders................12
SECTION 2.05. Conduct of Indemnification Proceedings..........................13
SECTION 2.06. Contribution....................................................14
SECTION 2.07. Participation in Public Offering................................15

                                    ARTICLE 3
                                  MISCELLANEOUS

SECTION 3.01. Entire Agreement................................................15
SECTION 3.02. Binding Effect; Benefit.........................................15
SECTION 3.03. Assignability...................................................16
SECTION 3.04. Amendment; Waiver...............................................16
SECTION 3.05. Obligations of Holdco and the Guarantors........................16
SECTION 3.06. Notices.........................................................16
SECTION 3.07. Headings........................................................17
SECTION 3.08. Counterparts....................................................18
SECTION 3.09. Applicable Law..................................................18
SECTION 3.10. Specific Enforcement............................................18
SECTION 3.11. Consent to Jurisdiction.........................................18




                                       2



                          REGISTRATION RIGHTS AGREEMENT

            AGREEMENT dated as of October 16,1998 among DLJ Investment Partners,
L.P., a Delaware limited partnership, DLJ ESC II L.P., a Delaware limited
partnership, DLJ Investment Funding, Inc., a Delaware corporation (each of the
foregoing, a "DLJ Entity", and collectively, the "DLJ Entities"), Credit Suisse
First Boston (Europe) Limited (the "CSFB Entity"), Chase Equity Associates, L.P.
(the "Chase Entity"), EnviroSystems Corp., a Delaware corporation ("Holdco"),
Environmental Systems Products Holdings Inc., a Delaware corporation ("ESPH"),
and certain direct or indirect subsidiaries of ESPH set forth on the signature
pages hereto (the "Guarantors", and together with ESPH, the "Issuer").

                              W I T N E S S E T H:

            WHEREAS, pursuant to the Senior Subordinated Note Subscription
Agreement (as defined below), the DLJ Entities, the CSFB Entity and the Chase
Entity have agreed severally to purchase in aggregate $100 million aggregate
principal amount of senior subordinated notes (the "Senior Subordinated Notes")
of the Issuer and will receive in aggregate 2,291.282 shares of Series A Common
Stock of Holdco ("Holdco Stock");

            WHEREAS, pursuant to the Senior Discount Note Subscription Agreement
(as defined below), certain of the DLJ Entities and their affiliates and the
Chase Entity have agreed to purchase senior discount notes of Holdco (the
"Discount Notes") and receive shares of Holdco Stock;

            WHEREAS, the parties hereto, certain affiliates of the DLJ Entities,
the Chase Entity and certain other shareholders of Holdco have entered into an
Investors Agreement dated as of even date herewith (the "Investors Agreement")
in connection with the acquisition of the Discount Notes and shares of Holdco
Stock;

            WHEREAS, the Issuer desires to provide registration rights for the
DLJ Entities, the CSFB Entity and the Chase Entity with regard to the Senior
Subordinated Notes;

            WHEREAS, the execution of this Agreement is a condition precedent to
the transactions contemplated by the Senior Subordinated Note Subscription
Agreement;

            NOW, THEREFORE the parties hereto agree as follows:

                                    ARTICLE 1

                                   DEFINITIONS

            SECTION 1.01. Definitions. (a) The following terms, as used herein,
have the following meanings:

                                       i



            "Affiliate" means, with respect to any Person, any other Person
directly or indirectly controlling, controlled by, or under common control with
such Person; provided that no securityholder of ESPH shall be deemed an
Affiliate of any other Securitybolder solely by reason of any investment in
ESPH. For the purpose of this definition, the term "control" (including with
correlative meanings, the terms "controlling", "controlled by" and "under common
control with"), as used with respect to any Person, shall mean the possession,
directly or indirectly, of the power to direct or cause the direction of the
management and policies of such Person, whether through the ownership of voting
securities or by contract or otherwise.

            "Affiliated Employee Benefit Trust" means any trust that is a
successor to the assets held by a trust established under an employee benefit
plan subject to ERISA or any other trust established directly or indirectly
under such plan or any other such plan having the same sponsor.

            "Business Day" means any day except a Saturday, Sunday or other day
on which commercial banks in New York City are authorized by law to close.

            "CSFBC" means Credit Suisse First Boston Corporation.

            "Envirotest" means Envirotest Systems Corp., a Delaware corporation.

            "ERISA" means the Employee Retirement Income Security Act of 1974,
as amended.

            "ESP" means Environmental Systems Products, Inc., a Delaware
corporation.

            "Exchange Act" means the Securities Exchange Act of 1934, as
amended.

            "Permitted Transferee" means:

            (i) in the case of any DLJ Entity, (A) any other DLJ Entity, (B) any
      general or limited partner of any such entity (a "DLJ Partner"), and any
      corporation, partnership, Affiliated Employee Benefit Trust or other
      entity which is an Affiliate of any DLJ Partner (collectively, the "DLJ
      Affiliates"), (C) any managing director, general partner, director,
      limited partner, officer or employee of such DLJ Entity or a DLJ
      Affiliate, or the heirs, executors, administrators, testamentary trustees,
      legatees or beneficiaries of any of the foregoing Persons referred to in
      this clause (C) (collectively, "DLJ Associates"), (D) any trust, the
      beneficiaries of which, or any corporation, limited liability company or
      partnership, the stockholders, members or general or limited partners of
      which, include only such DLJ Entity, DLJ Affiliates, DLJ Associates, their
      spouses or their lineal descendants and (E) a voting trustee for one or
      more DLJ Entities, DLJ Affiliates or DLJ Associates under the terms of a
      voting trust;

            (ii) in the case of any CSFB Entity, (A) any general or limited
      partner of any such entity (a "CSFB Partner"), and any corporation,
      partnership, Affiliated Employee Benefit Trust or other entity which is an
      Affiliate of any CSFB Partner (collectively, the "CSFB Affiliates"), (B)
      any managing director, general partner, director, limited partner, 


                                      -2-



      officer or employee of such CSFB Entity or a CSFB Affiliate, or the heirs,
      executors, administrators, testamentary trustees, legatees or
      beneficiaries of any of the foregoing Persons referred to in this clause
      (B) (collectively, "CSFB Associates"), (C) any trust, the beneficiaries of
      which, or any corporation, limited liability company or partnership, the
      stockholders, members or general or limited partners of which, include
      only such CSFB Entity, CSFB Affiliates, CSFB Associates, their spouses or
      their lineal descendants and (D) a voting trustee for one or more CSFB
      Entities, CSFB Affiliates or CSFB Associates under the terms of a voting
      trust; and

            (iii) in the case of any Chase Entity, (A) any general or limited
      partner of any such entity (a "Chase Partner"), and any corporation,
      partnership, Affiliated Employee Benefit Trust or other entity which is an
      Affiliate of any Chase Partner (collectively, the "Chase Affiliates"), (B)
      any managing director, general partner, director, limited partner, officer
      or employee of such Chase Entity or a Chase Affiliate, or the heirs,
      executors, administrators, testamentary trustees, legatees or
      beneficiaries of any of the foregoing Persons referred to in this clause
      (B) (collectively, "Chase Associates"), (C) any trust, the beneficiaries
      of which, or any corporation, limited liability company or partnership,
      the stockholders, members or general or limited partners of which, include
      only such Chase Entity, Chase Affiliates, Chase Associates, their spouses
      or their lineal descendants and (D) a voting trustee for one or more Chase
      Entities, Chase Affiliates or Chase Associates under the terms of a voting
      trust.

            "Person" means an individual, corporation, partnership, association,
trust or other entity or organization, including a government or political
subdivision or an agency or instrumentality thereof.

            "Registrable Securities" means, with respect to any Securityholder
or its Permitted Transferees, any principal amount of the Senior Subordinated
Notes (including any Private Exchange Securities) owned by such Securityholder
or its Permitted Transferees until (i) a registration statement covering such
securities has been declared effective by the SEC and such securities have been
disposed of pursuant to such effective registration statement, (ii) such
securities are sold under circumstances in which all of the applicable
conditions of Rule 144 (or any similar provisions then in force) under the
Securities Act are met or (iii) such securities are otherwise transferred, the
Issuer has delivered a new certificate or other evidence of ownership for such
securities not bearing the legend required pursuant to this Agreement and such
securities may be resold without subsequent registration under the Securities
Act.

            "Registration Expenses" means (i) all registration and filing fees,
(ii) fees and expenses of compliance with securities or blue sky laws (including
reasonable fees and disbursements of counsel in connection with blue sky
qualifications of the Securities), (iii) printing expenses, (iv) internal
expenses of the Issuer (including, without limitation, all salaries and expenses
of its officers and employees performing legal or accounting duties), (v) fees
and disbursements of counsel for the Issuer and customary fees and expenses for
independent certified public accountants retained by the Issuer (including
expenses relating to any comfort letters or costs associated with the delivery
by independent certified public accountants of a comfort letter or comfort
letters requested pursuant to Section 2.02(h) hereof), (vi) the fees and
expenses of any 


                                      -3-



special experts retained by the Issuer in its discretion in connection with such
registration, (vii) reasonable fees and expenses of one counsel for the DLJ
Entities participating in the offering, selected by the DLJ Entities, reasonable
fees and expenses of one counsel for the CSFB Entity participating in the
offering, selected by the CSFB Entity, and reasonable fees and expenses of one
counsel for the Chase Entity participating in the offering, selected by the
Chase Entity, (viii) fees and expenses in connection with any review of
underwriting arrangements by the National Association of Securities Dealers,
Inc. (the "NASD") including fees and expenses of any "qualified independent
underwriter" and (ix) fees and disbursements of underwriters customarily paid by
issuers or sellers of securities, but shall not include any underwriting fees,
discounts or commissions attributable to the sale of Registrable Securities, or
any out-of-pocket expenses (except as set forth in clause (vii) above) of the
Securityholders or any fees and expenses of underwriter's counsel.

            "SEC" means the Securities and Exchange Commission.

            "Securities" means the Senior Subordinated Notes and any other debt
or equity securities of the Issuer.

            "Securities Act" means the Securities Act of 1933, as amended.

            "Securityholder" means each Person (other than Holdco and the
Issuer) who shall be a party to this Agreement, whether in connection with the
execution and delivery hereof as of the date hereof, pursuant to Section 3.03 or
otherwise, so long as such Person shall "beneficially own" (as such term is
defined in Rule 13d-3 under the Exchange Act) any Senior Subordinated Notes.

            "Senior Discount Note Subscription Agreement" means the Subscription
Agreement dated as of October 15, 1998 among Holdco, ESPH, ESP, Envirotest, and
the Purchasers named therein relating to the Senior Discount Notes and shares of
Holdco Stock.

            "Senior Subordinated Note Subscription Agreement" means the
Subscription Agreement dated as of October 15, 1998 among Holdco, ESPH, the
Guarantors and the Purchasers named therein relating to the Senior Subordinated
Notes and shares of Holdco Stock.

            "Subsidiary" means, with respect to any Person, any entity of which
securities or other ownership interests having ordinary voting power to elect a
majority of the board of directors or other persons performing similar functions
are at the time directly or indirectly owned by such Person.

            "Transaction Documents" mean this Agreement, the Senior Discount
Note Subscription Agreement, the Senior Subordinated Note Subscription
Agreement, the Placement Agreements dated October 15, 1998 among Holdco, ESPH,
CSFBC and the other parties thereto, and the Investors Agreement.

            "Underwritten Public Offering" means an underwritten public offering
of Securities of the Issuer pursuant to an effective registration statement
under the Securities Act.


                                      -4-



            (b) The term "DLJ Entities", to the extent such entities shall have
transferred any of their Securities to Permitted Transferees, shall mean the DLJ
Entities and the Permitted Transferees of the DLJ Entities, taken together, and
any right or action that may be taken at the election of the DLJ Entities may be
taken at the election of the DLJ Entities, and such Permitted Transferees.

            (c) The term "CSFB Entity", to the extent such entity shall have
transferred any of its Securities to Permitted Transferees, shall mean the CSFB
Entity and the Permitted Transferees of the CSFB Entity, taken together, and any
right or action that may be taken at the election of the CSFB Entity may be
taken at the election of the CSFB Entity, and such Permitted Transferees.

            (d) The term "Chase Entity", to the extent such entity shall have
transferred any of its Securities to Permitted Transferees, shall mean the Chase
Entity and the Permitted Transferees of the Chase Entity, taken together, and
any right or action that may be taken at the election of the Chase Entity may be
taken at the election of the Chase Entity, and such Permitted Transferees.

            (e) Each of the following terms is defined in the Section set forth
opposite such term:


            Term                                             Section
            ----                                             -------
                                                          
            Demand Registration                              2.01 (c)
            Exchange Offer Registration Rights Agreement     2.01 (a)
            Exchange Offer Registration Statement            2.01 (a)
            Holders                                          2.01 (c)
            Indemnified Party                                2.05
            Indemnifying Party                               2.05
            Initial Registration                             2.01(b)
            Inspectors                                       2.02(g)
            NASD                                             1.01(a)
            Records                                          2.02(g)
            Registered Exchange Offer                        2.01(a)
            Rule 144A Offering Memorandum                    2.01(a)
            Rule 144A Sellers                                2.01(a)
            Selling Securityholder                           2.01(c)




                                    ARTICLE 2

                               REGISTRATION RIGHTS

            SECTION 2.01. Rule 144A Matters, Initial Registration and Demand
Registration. (a) Immediately following the date hereof, the Issuer will as
promptly as practicable prepare an offering memorandum (as amended or
supplemented, the "Rule 144A Offering Memorandum") relating to the Senior
Subordinated Notes so that such Senior Subordinated


                                      -5-



Notes may be resold by the CSFB Entity (and if so prepared for the CSFB Entity,
by the DLJ Entities or the Chase Entity if they elect to participate) (the
participating CSFB Entity, DLJ Entities and the Chase Entity are hereinafter
referred to as the "Rule 144A Sellers") pursuant to Rule 144A or Regulation S
under the Securities Act. Such Rule 144A Offering Memorandum shall contain such
disclosures as are customary and appropriate for such a document. In addition,
in connection with the preparation of such Rule 144A Offering Memorandum, the
Issuer shall (i) execute such customary and appropriate documents or agreements
relating to such Senior Subordinated Notes and their terms including providing
for customary opinions, comfort letters and indemnification provisions relating
to the Rule 144A Offering Memorandum, as determined by the Rule 144A Sellers and
reasonably agreed to by the Issuer, and (ii) enter into a registration rights
agreement in form and substance reasonably satisfactory to the Issuer and the
Rule 144A Sellers that provides for the exchange of Senior Subordinated Notes
for securities with substantially the same terms and conditions as the Senior
Subordinated Notes except for transfer restrictions (the "Exchange Offer
Registration Rights Agreement"). As used in this Section 2.01 (a), the term
"customary and appropriate" shall be determined with reference to Rule 144A
transactions underwritten by nationally recognized investment banking firms and
involving securities that are similar to the Senior Subordinated Notes and that
are issued by entities that are not subject to the reporting requirements of the
Exchange Act.

            The Issuer will promptly advise the Rule 144A Sellers of the
happening of any event that would require an amendment of or supplement to the
Rule 144A Offering Memorandum then being used so that the Rule 144A Offering
Memorandum as thereafter delivered to purchasers would not include any untrue
statement of a material fact or omit to state a material fact necessary to make
the statements therein not misleading. Upon receipt of such notice, the Rule
144A Sellers shall cease delivering such Rule 144A Offering Memorandum to
prospective purchasers of the Senior Subordinated Notes until such time as such
amended or supplemented Rule 144A Offering Memorandum is available for delivery
to such prospective purchasers. The Issuer will also give the Rule 144A Sellers
notice of any intention to make any amendment or supplement to the Rule 144A
Offering Memorandum, will furnish the Rule 144A Sellers in advance with copies
of any such amendment or supplement proposed to be made and will not permit any
such amendment or supplement to be made without first consulting with the Rule
144A Sellers and their counsel.

            The Issuer will furnish to the Rule 144A Sellers copies of the Rule
144A Offering Memorandum and all amendments and supplements thereto, in each
case as soon as available and in such quantities as the Rule 144A Sellers may
reasonably request.

            Unless otherwise agreed to by all of the parties hereto, the right
of the Rule 144A Sellers to resell Senior Subordinated Notes pursuant to this
Section 2.01(a) (other than pursuant to the Exchange Offer Registration Rights
Agreement) shall expire upon the earlier of (x) the sale of all of the Senior
Subordinated Notes pursuant to the Rule 144A Offering Memorandum or (y) the
Business Day immediately prior to the earlier of (A) the filing of the Initial
Registration and (B) the filing of the Exchange Offer Registration Statement.

            The Exchange Offer Registration Rights Agreement shall provide,
among other things, that the Issuer shall, if Senior Subordinated Notes have
been sold under the Rule 144A 


                                      -6-



Offering Memorandum, at its own cost, use its reasonable best efforts to prepare
and, not later than 60 days after (or if the 60th day is not a Business Day, the
first Business Day thereafter) the date hereof, file with the SEC a registration
statement ("Exchange Offer Registration Statement") on an appropriate form under
the Securities Act, with respect to a proposed offer (the "Registered Exchange
Offer") to the holders of Senior Subordinated Notes sold under the Rule 144A
Offering Memorandum, who are not prohibited by any law or policy of the SEC from
participating in the Registered Exchange Offer, to issue and deliver to such
holders, in exchange for such Senior Subordinated Notes, a like aggregate
principal amount of debt securities of the Issuer issued under the indenture
relating to the Senior Subordinated Notes (the "Exchange Securities") and
identical in all material respects to the Senior Subordinated Notes (except for
the transfer restrictions relating to the initial Senior Subordinated Notes)
that would be registered under the Securities Act. The Issuer shall use its
reasonable best efforts to cause such Exchange Offer Registration Statement to
become effective under the Securities Act within 150 days (or if the 150th day
is not a Business Day, the first Business Day thereafter) from the date hereof
and shall keep the Exchange Offer Registration Statement effective for not less
than 30 days (or longer, if required by applicable law) after the date notice of
the Registered Exchange Offer is mailed to the holders.

            Prior to the filing of the Exchange Offer Registration Statement and
the registration statement related to the Initial Registration, the parties
hereto shall use their reasonable best efforts to take such actions as are
necessary such that the Exchange Securities and the Securities (the "Initial
Securities") held by the CSFB Entity, the DLJ Entities and the Chase Entity (the
"Original Holders") after being registered pursuant to the Initial Registration
(as defined below) are traded as fungible securities, including, if appropriate,
legal and in compliance with the Securities Act, having the Issuer,
simultaneously with the delivery of the Exchange Securities pursuant to the
Registered Exchange Offer, issue and deliver to such Original Holders upon the
written request of such Original Holders, in exchange for the Initial Securities
held by such Original Holders, a like principal amount of debt securities (the
"Private Exchange Securities") of the Issuer issued under the indenture relating
to the Senior Subordinated Notes and identical in all material respects (other
than the inclusion of provisions relating to restrictions on transfer under the
Securities Act and the securities laws of the several states of the United
States identical to such provisions in the Initial Securities), to the Exchange
Securities.

            (b) In addition to the Issuer's obligations under Section 2.01(a),
the Issuer will (i) file a registration statement under the Securities Act
relating to all of the Registrable Securities held by the Securityholders (the
"Initial Registration") within 60 days from the date hereof (or if the 60th day
is not a Business Day, the first Business Day thereafter), and (ii) use its
reasonable best efforts to have such registration statement declared effective
within 150 days from the date hereof (or if the 150th day is not a Business Day,
the first Business Day thereafter), all to the extent necessary to permit the
disposition (in accordance with the intended methods thereof) of the Registrable
Securities. Securityholders representing a majority of the outstanding principal
amount of the Registrable Securities may, at any time prior to the effective
date of the registration statement relating to such registration, revoke such
request, without liability to any of the other Securityholders, by providing a
written notice to ESPH revoking such request.


                                      -7-



            (c) In the event that all of the Senior Subordinated Notes have not
been sold under the Rule 144A Offering Memorandum pursuant to Section 2.01 (a)
or under the Initial Registration pursuant to Section 2.01(b), subject to the
provisions herein, from and after the date which is twelve months after the date
effectiveness of any registration statement pursuant to Section 2.01(b) expires,
any DLJ Entity, the CSFIB Entity or the Chase Entity that holds Registrable
Securities may make a written request (any such requesting Person, a "Selling
Securityholder") that the Issuer effect the registration under the Securities
Act of all or a portion of such Selling Securityholder's Registrable Securities,
which request shall specify the intended method of disposition thereof. All such
written requests will be sent to ESPH and each potential Selling Securityholder
and more than one Selling Securityholder may request a Demand Registration (as
defined below) at the same time. The Issuer will promptly give written notice of
such requested registration (a "Demand Registration") at least 30 days prior to
the anticipated filing date of the registration statement relating to such
Demand Registration to all other Securityholders and thereupon will use its best
efforts to effect, as expeditiously as possible, the registration under the
Securities Act of the Registrable Securities which the Issuer has been so
requested to register by the Selling Securityholders and the Registrable
Securities which the other Securityholders have requested the Issuer to register
by written request received by ESPH within 15 days after the receipt by such
Securityholders of such written notice given by the Issuer (all such
Securityholders, together with the Selling Securityholders, the "Holders"), all
to the extent necessary to permit the disposition (in accordance with the
intended methods thereof as aforesaid) of the Registrable Securities so to be
registered; provided that, subject to Section 2.01(e) hereof, the Issuer shall
not be obligated to effect more than one Demand Registration pursuant to this
Section 2.01. Promptly after the expiration of the 15-day period referred to
above, the Issuer will notify all the Holders to be included in the Demand
Registration of the other Holders and the number of shares of Registrable
Securities requested to be included therein. The Selling Securityholders
requesting a registration under this Section 2.01 may, at any time prior to the
effective date of the registration statement relating to such registration,
revoke such request, without liability to any of the other Holders, by providing
a written notice to ESPH revoking such request, in which case such request, so
revoked, shall be not considered a Demand Registration; provided that all
Registration Expenses relating to such revoked registration are reimbursed by
such Selling Securityholders (unless such revocation arose out of the fault of
the Issuer, in which case no such reimbursement need be made).

            (d) The Issuer will pay all Registration Expenses in connection with
any registration pursuant to this Section 2.01.

            (e) The Initial Registration or a Demand Registration pursuant to
this Section 2.01 shall not be deemed to have been effected unless the
registration statement relating thereto (i) has become effective under the
Securities Act and (ii) has remained effective for a period of, in the case of
the Initial Registration, at least 180 days (or such shorter period in which all
Registrable Securities included in such registration have actually been sold
thereunder) and, in the case of a Demand Registration, at least 90 days (or such
shorter period in which all Registrable Securities included in such registration
have actually been sold thereunder); provided that, if after any such
registration statement becomes effective such registration statement is
interfered with by any stop order, injunction or other order or requirement of
the SEC or other governmental agency or court, such registration statement shall
be at the sole expense of the Issuer and shall not be 


                                       -8-



considered the Initial Registration or a Demand Registration, unless any such
interference referred to in this proviso arose out of the fault of the Holders
of the Registrable Securities included in such registration statement, in which
case such registration statement shall be considered the Initial Registration or
a Demand Registration, as the case may be.

            SECTION 2.02. Registration Procedures. Pursuant to Section 2.01(b)
and whenever Securityholders request that any Registrable Securities be
registered pursuant to Section 2.01(c), the Issuer will, subject to the
provisions of such Sections, use its best efforts to effect the registration and
the sale of such Registrable Securities in accordance with the intended method
of disposition thereof as quickly as practicable, and in connection with any
such request:

            (a) The Issuer will as expeditiously as possible (in the case of the
      Initial Registration, within 60 days from the date hereof) prepare and
      file with the SEC a registration statement on any form for which the
      Issuer then qualifies or which counsel for the Issuer shall deem
      appropriate and which form shall be available for the sale of the
      Registrable Securities to be registered thereunder in accordance with the
      intended method of distribution thereof, and use its best efforts (in the
      case of the Initial Registration, within 150 days from the date hereof) to
      cause such filed registration statement to become effective and to remain
      effective for a period of, in the case of the Initial Registration, not
      less than 180 days (or such shorter period in which all of the Registrable
      Securities of the Securityholders included in such registration statement
      shall have actually been sold thereunder) and, in the case of a Demand
      Registration, not less than 90 days (or such shorter period in which all
      of the Registrable Securities of the Securityholders included in such
      registration statement shall have actually been sold thereunder).

            (b) The Issuer will, if requested, prior to filing a registration
      statement or prospectus or any amendment or supplement thereto, furnish to
      each Securityholder and each underwriter, if any, of the Registrable
      Securities covered by such registration statement copies of such
      registration statement as proposed to be filed, and thereafter the Issuer
      will furnish to such Securityholder and underwriter, if any, such number
      of copies of such registration statement, each amendment and supplement
      thereto (in each case including all exhibits thereto and documents
      incorporated by reference therein), the prospectus included in such
      registration statement (including each preliminary prospectus) and such
      other documents as such Securityholder or underwriter may reasonably
      request in order to facilitate the disposition of the Registrable
      Securities owned by such Securityholder. Each Securityholder shall have
      the right to request that the Issuer modify any information contained in
      such registration statement, amendment and supplement thereto pertaining
      to such Securityholder and the Issuer shall use its reasonable best
      efforts to comply with such request, provided that the Issuer shall not
      have any obligation to so modify any information if so doing would cause
      the prospectus to contain an untrue statement of a material fact or omit
      to state any material fact required to be stated therein or necessary to
      make the statements therein not misleading.

            (c) After the filing of the registration statement, the Issuer will
      cause the related prospectus to be supplemented by any required prospectus
      supplement, and as so supplemented to be filed pursuant to Rule 424 under
      the Securities Act, (ii) comply with 


                                      -9-



      the provisions of the Securities Act with respect to the disposition of
      all Registrable Securities covered by such registration statement during
      the applicable period in accordance with the intended methods of
      disposition by the sellers thereof set forth in such registration
      statement or supplement to such prospectus and promptly notify each
      Securityholder holding Registrable Securities covered by such registration
      statement of any stop order issued or threatened by the SEC and take all
      reasonable actions required to prevent the entry of such stop order or to
      remove it if entered.

            (d) The Issuer will use its best efforts to (i) register or qualify
      the Registrable Securities covered by such registration statement under
      such other securities or blue sky laws of such jurisdictions in the United
      States as any Securityholder holding such Registrable Securities
      reasonably (in light of such Securityholder's intended plan of
      distribution) requests and (ii) cause such Registrable Securities to be
      registered with or approved by such other governmental agencies or
      authorities as may be necessary by virtue of the business and operations
      of the Issuer and do any and all other acts and things that may be
      reasonably necessary or advisable to enable such Securityholder to
      consummate the disposition of the Registrable Securities owned by such
      Securityholder; provided that the Issuer will not be required to (A)
      qualify generally to do business in any jurisdiction where it would not
      otherwise be required to qualify but for this paragraph (d), (B) subject
      itself to taxation in any such jurisdiction or (C) consent to general
      service of process in any such jurisdiction.

            (e) The Issuer will immediately notify each Securityholder holding
      such Registrable Securities covered by such registration statement, at any
      time when a prospectus relating thereto is required to be delivered under
      the Securities Act, of the occurrence of an event requiring the
      preparation of a supplement or amendment to such prospectus so that, as
      thereafter delivered to the purchasers of such Registrable Securities,
      such prospectus will not contain an untrue statement of a material fact or
      omit to state any material fact required to be stated therein or necessary
      to make the statements therein not misleading and promptly prepare and
      make available to each such Securityholder and file with the SEC any such
      supplement or amendment.

            (f) Except as provided below, the Issuer may select the underwriter
      or underwriters in connection with the Initial Registration and any Demand
      Registration as it may deem appropriate. If the Initial Registration is an
      Underwritten Public Offering, the DLJ Entities will have the right to
      select one co-lead managing underwriter and, if the CSFB Entity has
      Registrable Securities covered by such registration, the CSFB Entity will
      have the right to select the other co-lead managing underwriter provided
      that if the CSFB Entity has no Registrable Securities covered by such
      registration, the DLJ Entities will have the right to select the lead
      managing underwriter. If any Demand Registration is an Underwritten Public
      Offering, the DLJ Entities and, if the CSFB Entity has Registrable
      Securities covered by such registration, the CSFB Entity will each have
      the right to select one of the co-lead managing underwriters; provided
      that such Entities or Entity, as the case may be, have Registrable
      Securities covered by such registration. Any Affiliate of any of the DLJ
      Entities or any affiliate of the CSFB Entities may be selected as
      underwriter for the Initial Registration and any Demand Registration. The
      Issuer will 


                                      -10-



      enter into customary agreements (including an underwriting agreement in
      customary form) and take such other actions as are reasonably required in
      order to expedite or facilitate the disposition of such Registrable
      Securities, including the engagement of a "qualified independent
      underwriter" in connection with the qualification of the underwriting
      arrangements with the NASD. If any DLJ Entity elects to be a Rule 144A
      Seller, the DLJ Entities will have the right to select one co-lead
      managing underwriter or placement agent and the CSFB Entity will have the
      right to select the other co-lead managing underwriter or placement agent
      in connection with sales under the Rule 144A Offering Memorandum.

            (g) The Issuer will make available for inspection by any
      Securityholder and any underwriter participating in any disposition
      pursuant to a registration statement being filed by the Issuer pursuant to
      this Section 2.02 and any attorney, accountant or other professional
      retained by any such Securityholder or underwriter (collectively, the
      "Inspectors"), all financial and other records, pertinent corporate
      documents and properties of the Issuer (collectively, the "Records") as
      shall be reasonably requested by any such Person, and cause the Issuer's
      officers, directors and employees to supply all information reasonably
      requested by any Inspectors in connection with such registration
      statement.

            (h) The Issuer will furnish to each such Securityholder and to each
      such underwriter, if any, a signed counterpart, addressed to such
      underwriter, of (i) an opinion or opinions of counsel to the Issuer and
      (ii) a comfort letter or comfort letters from the Issuer's independent
      public accountants, each in customary form and covering such matters of
      the type customarily covered by opinions or comfort letters, as the case
      may be, as a majority of such Securityholders or the managing underwriter
      therefor reasonably requests.

            (i) The Issuer will otherwise use its best efforts to comply with
      all applicable rules and regulations of the SEC, and make available to its
      securityholders, as soon as reasonably practicable, an earnings statement
      covering a period of 12 months, beginning within three months after the
      effective date of the registration statement, which earnings statement
      shall satisfy the provisions of Section 11(a) of the Securities Act.

            (j) The Issuer may require each such Securityholder to promptly
      furnish in writing to the Issuer such information regarding the
      distribution of the Registrable Securities as the Issuer may from time to
      time reasonably request and such other information as may be legally
      required in connection with such registration.

            (k) Each such Securityholder agrees that, upon receipt of any notice
      from the Issuer of the happening of any event of the kind described in
      Section 2.02(e) hereof, such Securityholder will forthwith discontinue
      disposition of Registrable Securities pursuant to the registration
      statement covering such Registrable Securities until such Securityholder's
      receipt of the copies of the supplemented or amended prospectus
      contemplated by Section 2.02(e) hereof, and, if so directed by the Issuer,
      such Securityholder will deliver to the Issuer all copies, other than any
      permanent file copies then in such Securityholder's possession, of the
      most recent prospectus covering such Registrable Securities at the time 


                                      -11-



      of receipt of such notice. In the event that the Issuer shall give such
      notice, the Issuer shall extend the period during which such registration
      statement shall be maintained effective (including the period referred to
      in Section 2.02(a) hereof) by the number of days during the period from
      and including the date of the giving of notice pursuant to Section 2.02(e)
      hereof to the date when the Issuer shall make available to such
      Securityholder a prospectus supplemented or amended to conform with the
      requirements of Section 2.02(e) hereof.

            SECTION 2.03. Indemnification by the Issuer. The Issuer agrees to
indemnify and hold harmless each Securityholder holding Registrable Securities
covered by a registration statement, its officers, directors and agents, and
each Person, if any, who controls such Securityholder within the meaning of
Section 15 of the Securities Act or Section 20 of the Exchange Act from and
against any and all losses, claims, damages and liabilities caused by any untrue
statement or alleged untrue statement of a material fact contained in any
registration statement or prospectus relating to the Registrable Securities (as
amended or supplemented if the Issuer shall have furnished any amendments or
supplements thereto) or any preliminary prospectus, or caused by 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, except insofar as
such losses, claims, damages or liabilities are caused by any such untrue
statement or omission or alleged untrue statement or omission so made in strict
conformity with information furnished in writing to the Issuer by such
Securityholder or on such Securityholder's behalf expressly for use therein;
provided that with respect to any untrue statement or omission or alleged untrue
statement or omission made in any preliminary prospectus, or in any prospectus,
as the case may be, the indemnity agreement contained in this paragraph shall
not apply to the extent that any such loss, claim, damage, liability or expense
results from the fact that a current copy of the prospectus (or, in the case of
a prospectus, the prospectus as amended or supplemented) was not sent or given
to the Person asserting any such loss, claim, damage, liability or expense at or
prior to the written confirmation of the sale of the Registrable Securities
concerned to such Person if it is determined that the Issuer has provided such
prospectus and it was the responsibility of such Securityholder to provide such
Person with a current copy of the final prospectus (or such amended or
supplemented prospectus, as the case may be) and such current copy of the final
prospectus (or such amended or supplemented prospectus, as the case may be)
would have cured the defect giving rise to such loss, claim, damage, liability
or expense. The Issuer also agrees to indemnify any underwriters of the
Registrable Securities, their officers and directors and each person who
controls such underwriters on substantially the same basis as that of the
indemnification of the Securityholders provided in this Section 2.03.

            SECTION 2.04. Indemnification by Participating Securityholders. (a)
Subject to Section 2.04(b), each Securityholder holding Registrable Securities
included in any registration statement agrees, severally but not jointly, to
indemnify and hold harmless the Issuer, its officers, directors and agents and
each Person, if any, who controls the Issuer within the meaning of either
Section 15 of the Securities Act or Section 20 of the Exchange Act to the same
extent as the foregoing indemnity from the Issuer to such Securityholder, but
only (i) with respect to information furnished in writing by such Securityholder
or on such Securityholder's behalf expressly for use in any registration
statement or prospectus relating to the Registrable Securities, or any amendment
or supplement thereto, or any preliminary prospectus or (ii) to the extent that


                                      -12-



any loss, claim, damage, liability or expense described in Section 2.03 results
from the fact that a current copy of the prospectus (or, in the case of a
prospectus, the prospectus as amended or supplemented) was not sent or given to
the Person asserting any such loss, claim, damage, liability or expense at or
prior to the written confirmation of the sale of the Registrable Securities
concerned to such Person if it is determined that it was the responsibility of
such Securityholder to provide such Person with a current copy of the prospectus
(or such amended or supplemented prospectus, as the case may be) and such
current copy of the prospectus (or such amended or supplemented prospectus, as
the case may be) would have cured the defect giving rise to such loss, claim,
damage, liability or expense. Subject to Section 2.04(b), each such
Securityholder also agrees to indemnify and hold harmless underwriters of the
Registrable Securities, their officers and directors and each person who
controls such underwriters on substantially the same basis as that of the
indemnification of the Issuer provided in this Section 2.04. As a condition to
including Registrable Securities in any registration statement filed in
accordance with Article 2 hereof, the Issuer may require that it shall have
received an undertaking reasonably satisfactory to it from any underwriter to
indemnify and hold it harmless to the extent customarily provided by
underwriters with respect to similar securities.

            (b) No Securityholder shall be liable under Section 2.04(a) for any
damage thereunder in excess of the net proceeds realized by such Securityholder
in the sale of the Registrable Securities of such Securityholder.

            SECTION 2.05. Conduct of Indemnification Proceedings. In case any
proceeding (including any governmental investigation) shall be instituted
involving any Person in respect of which indemnity may be sought pursuant to
this Article 2, such Person (an "Indemnified Party") shall promptly notify the
Person against whom such indemnity may be sought (the "Indemnifying Party") in
writing and the Indemnifying Party shall assume the defense thereof, including
the employment of counsel reasonably satisfactory to such Indemnified Party, and
shall assume the payment of all fees and expenses; provided that the failure of
any Indemnified Party so to notify the Indemnifying Party shall not relieve the
Indemnifying Party of its obligations hereunder except to the extent that the
Indemnifying Party is materially prejudiced by such failure to notify. In any
such proceeding, any Indemnified Party shall have the right to retain its own
counsel, but the fees and expenses of such counsel shall be at the expense of
such Indemnified Party unless (i) the Indemnifying Party and the Indemnified
Party shall have mutually agreed to the retention of such counsel or (ii) in the
reasonable judgment of such Indemnified Party representation of both parties by
the same counsel would be inappropriate due to actual or potential differing
interests between them. It is understood that the Indemnifying Party shall not,
in connection with any proceeding or related proceedings in the same
jurisdiction, be liable for the reasonable fees and expenses of more than one
separate firm of attorneys (in addition to any local counsel) at any time for
all such Indemnified Parties, and that all such fees and expenses shall be
reimbursed as they are incurred. In the case of any such separate firm for the
Indemnified Parties, such firm shall be designated in writing by the Indemnified
Parties. The Indemnifying Party shall not be liable for any settlement of any
proceeding effected without its written consent, but if settled with such
consent, or if there be a final judgment for the plaintiff, the Indemnifying
Party shall indemnify and hold harmless such Indemnified Parties from and
against any and all losses, claims, damages, liabilities and expenses or
liability (to the extent stated above) by reason of such settlement or judgment.
No Indemnifying Party shall, without the prior written consent of the
Indemnified Party, effect any 


                                      -13-



settlement of any pending or threatened proceeding in respect of which any
Indemnified Party is or could have been a party and indemnity could have been
sought hereunder by such Indemnified Party, unless such settlement includes an
unconditional release of such Indemnified Party from all liability arising out
of such proceeding.

            SECTION 2.06. Contribution. If the indemnification provided for in
this Article 2 is held by a court of competent jurisdiction to be unavailable to
the Indemnified Parties in respect of any losses, claims, damages or liabilities
referred to herein, then each such 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 losses, claims, damages or liabilities (i)
as between the Issuer and the Securityholders holding Registrable Securities
covered by a registration statement on the one hand and the underwriters on the
other, in such proportion as is appropriate to reflect the relative benefits
received by the Issuer and such Securityholders on the one hand and the
underwriters on the other, from the offering of the Registrable Securities, or
if such allocation is not permitted by applicable law, in such proportion as is
appropriate to reflect not only the relative benefits but also the relative
fault of the Issuer and such Securityholders on the one hand and of such
underwriters on the other in connection with the statements or omissions which
resulted in such losses, claims, damages or liabilities, as well as any other
relevant equitable considerations and (ii) as between the Issuer on the one hand
and each such Securityholder on the other, in such proportion as is appropriate
to reflect the relative fault of the Issuer and of each such Securityholder in
connection with such statements or omissions, as well as any other relevant
equitable considerations. The relative benefits received by the Issuer and such
Securityholders on the one hand and such underwriters on the other shall be
deemed to be in the same proportion as the total proceeds from the offering (net
of underwriting discounts and commissions but before deducting expenses)
received by the Issuer and such Securityholders bear to the total underwriting
discounts and commissions received by such underwriters, in each case as set
forth in the table on the cover page of the prospectus. The relative fault of
the Issuer and such Securityholders on the one hand and of such underwriters on
the other shall be determined by reference to, among other things, whether the
untrue or alleged untrue statement of a material fact or the omission or alleged
omission to state a material fact relates to information supplied by the Issuer
and such Securityholders or by such underwriters. The relative fault of the
Issuer on the one hand and of each such Securityholder on the other shall be
determined by reference to, among other things, whether the untrue or alleged
untrue statement of a material fact or the omission or alleged omission to state
a material fact relates to information supplied by such party, and the parties'
relative intent, knowledge, access to information and opportunity to correct or
prevent such statement or omission.

            The Issuer and the Securityholders agree that it would not be just
and equitable if contribution pursuant to this Section 2.06 were determined by
pro rata allocation (even if the underwriters were treated as one entity for
such purpose) or by any other method of allocation which does not take account
of the equitable considerations referred to in the immediately preceding
paragraph. The amount paid or payable to an Indemnified Party as a result of the
losses, claims, damages or liabilities referred to in the immediately preceding
paragraph shall be deemed to include, subject to the limitations set forth
above, any legal or other expenses reasonably incurred by such Indemnified Party
in connection with investigating or defending any such action or claim.
Notwithstanding the provisions of this Section 2.06, no underwriter shall be


                                      -14-



required to contribute any amount in excess of the amount by which the total
price at which the Registrable Securities underwritten by it and distributed to
the public were offered to the public exceeds the amount of any damages which
such underwriter has otherwise been required to pay by reason of such untrue or
alleged untrue statement or omission or alleged omission, and no Securityholder
shall be required to contribute any amount in excess of the amount by which the
net proceeds realized on the sale of the Registrable Securities of such
Securityholder exceeds the amount of any damages which such Securityholder has
otherwise been required to pay by reason of such untrue or alleged untrue
statement or omission or alleged omission. No person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the Securities Act)
shall be entitled to contribution from any person who was not guilty of such
fraudulent misrepresentation. Each Securityholder's obligation to contribute
pursuant to this Section 2.06 is several in the proportion that the proceeds of
the offering received by such Securityholder bears to the total proceeds of the
offering received by all such Securityholders and not joint.

            SECTION 2.07. Participation in Public Offering. (a) No Person may
participate in the Initial Registration or any Demand Registration hereunder
unless such Person (i) agrees to sell such Person's securities on the basis
provided in any underwriting arrangements approved by the Persons entitled
hereunder to approve such arrangements and (ii) completes and executes all
questionnaires, powers of attorney, indemnities, underwriting agreements and
other documents reasonably required under the terms of such underwriting
arrangements and the provisions of this Agreement in respect of registration
rights.

            (b) In the event any Securityholder shall transfer any Registrable
Securities pursuant to Rule 144A under the Securities Act, the Issuer shall
cooperate with such Securityholder and shall use its reasonable best efforts to
provide to such Securityholder such information as such Securityholder shall
reasonably request.

                                    ARTICLE 3

                                  MISCELLANEOUS

            SECTION 3.01. Entire Agreement. The Transaction Documents constitute
the entire agreement between the parties with respect to the subject matter of
the Transaction Documents and supersede all prior agreements and understandings,
both oral and written, between the parties with respect to the subject matter of
this Agreement and the other Transaction Documents.

            SECTION 3.02. Binding Effect; Benefit. This Agreement shall inure to
the benefit of and be binding upon the parties hereto and their respective
heirs, successors, legal representatives and permitted assigns. Nothing in this
Agreement, expressed or implied, is intended to confer on any Person other than
the parties hereto, and their respective heirs, successors, legal
representatives and permitted assigns, any rights, remedies, obligations or
liabilities under or by reason of this Agreement.


                                      -15-



            SECTION 3.03. Assignability. Neither this Agreement nor any right,
remedy, obligation or liability arising hereunder or by reason hereof shall be
assignable by the Issuer or any Securityholder, except by any Securityholder to
its Permitted Transferees. Any Securityholder who ceases to beneficially own any
Securities shall cease to be bound by the terms hereof (other than Sections
2.04, 2.05 and 2.06).

            SECTION 3.04. Amendment; Waiver. No provision of this Agreement may
be waived except by an instrument in writing executed by the party against whom
the waiver is to be effective; provided that for purposes of any such waiver, an
instrument in writing executed by ESPH shall constitute an instrument in writing
executed by the Guarantors. No provision of this Agreement may be amended or
otherwise modified except by an instrument in writing executed by the parties
hereto; provided that for purposes of any such amendment or modification, an
instrument in writing executed by ESPH shall constitute an instrument in writing
executed by the Guarantors.

            SECTION 3.05. Obligations of Holdco and the Guarantors. Holdco will
take all action necessary to cause the Issuer to perform its obligations under
this Agreement on the terms and conditions set forth in this Agreement. ESPH
will take all action necessary to cause the Guarantors to perform their
obligations under this Agreement on the terms and conditions set forth in this
Agreement.

            SECTION 3.06. Notices. All notices and other communications given or
made pursuant hereto or pursuant to any other agreement among the parties,
unless otherwise specified, shall be in writing and shall be deemed to have been
duly given or made if sent by fax (with confirmation in writing), delivered
personally or sent by registered or certified mail (postage prepaid, return
receipt requested) to the parties at the fax number or address set forth below
or at such other addresses as shall be furnished by the parties by like notice,
and such notice or communication shall be deemed to have been given or made upon
receipt:

            if to the DLJ Entities, to:

            c/o DLJ Merchant Banking II, Inc.
            277 Park Avenue
            New York, NY 10172
            Attention: Ivy Dodes
            Fax: (212) 892-7272

            with a copy to:

            Davis Polk & Wardwell
            450 Lexington Avenue
            New York, New York 10017
            Attention: John Knight
            Fax: (212) 450-4800


                                      -16-



            if to the CSFB Entity, to:

            Credit Suisse First Boston (Europe) Limited
            c/o Credit Suisse First Boston Corporation
            11 Madison Avenue
            New York, NY 10010
            Attention: Richard Gallant
            Fax: (212) 325-9136

            with a copy to:

            Skadden, Arps, Slate, Meagher & Flom LLP
            919 Third Avenue
            New York, NY 10022-3897
            Attention: David J. Goldschmidt
            Fax: (212) 735-2000

            if to the Chase Entity, to:

            Chase Equity Associates, L.P.
            c/o Chase Capital Partners
            380 Madison Avenue, 12th Floor
            New York, NY 10017
            Attention: Richard D. Waters, Jr.
            Fax: (212) 622-3950

            if to Holdco or ESPH, to:

            Environmental Systems Products Holdings Inc.
            7 Kripes Road
            East Granby, CT 06026
            Attention: David J. Langevin
            Fax: (860) 653-4868

            with a copy to:

            White & Case LLP
            1155 Avenue of the Americas
            New York, NY 10036-2787
            Attention: Frank Schiff
            Fax: (212) 354-8113

            Any Person who becomes a Securityholder shall provide its address
and fax number to ESPH, which shall promptly provide such information to each
other Securityholder.

            SECTION 3.07. Headings. The headings contained in this Agreement are
for convenience only and shall not affect the meaning or interpretation of this
Agreement.


                                      -17-



            SECTION 3.08. Counterparts. This Agreement may be executed in any
number of counterparts, each of which shall be deemed to be an original and all
of which together shall be deemed to be one and the same instrument.

            SECTION 3.09. Applicable Law. This Agreement shall be governed by,
and construed in accordance with, the laws of the State of New York, without
regard to the conflicts of law rules of such state.

            SECTION 3.10. Specific Enforcement. Each party hereto acknowledges
that the remedies at law of the other parties for a breach or threatened breach
of this Agreement would be inadequate and, in recognition of this fact, any
party to this Agreement, without posting any bond, and in addition to all other
remedies which may be available, shall be entitled to obtain equitable relief in
the form of specific performance, a temporary restraining order, a temporary or
permanent injunction or any other equitable remedy which may then be available.

            SECTION 3.11. Consent to Jurisdiction. Any suit, action or
proceeding seeking to enforce any provision of, or based on any matter arising
out of or in connection with, this Agreement or the transactions contemplated
hereby shall be brought in the United States District Court for the Southern
District of New York or any other New York State court sitting in New York City,
and each of the parties hereby consents to the jurisdiction of such courts (and
of the appropriate appellate courts therefrom) in any such suit, action or
proceeding and irrevocably waives, to the fullest extent permitted by law, any
objection which it may now or hereafter have to the laying of the venue of any
such suit, action or proceeding in any such court or that any such suit, action
or proceeding which is brought in any such court has been brought in an
inconvenient forum. Process in any such suit, action or proceeding may be served
on any party anywhere in the world, whether within or without the jurisdiction
of any such court. Without limiting the foregoing, each party agrees that
service of process on such party as provided in Section 3.06 shall be deemed
effective service of process on such party.


                                      -18-



            IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be duly executed by their respective authorized officers as of the day and year
first above written.

                                          DLJ INVESTMENT PARTNERS, L.P.

                                          By:  DLJ INVESTMENT PARTNERS, INC.
                                               Managing General Partner


                                          By: /s/ Ivy Dodes
                                             -----------------------------------
                                             Name:  Ivy Dodes
                                             Title: Vice President

                                          DLJ ESC II L.P.

                                          By:  DLJ LBO PLANS MANAGEMENT 
                                               CORPORATION
                                               General Partner


                                          By: /s/ Ivy Dodes
                                             -----------------------------------
                                             Name:  Ivy Dodes
                                             Title: President

                                          DLJ INVESTMENT FUNDING, INC.


                                          By: /s/ Ivy Dodes
                                             -----------------------------------
                                             Name:  Ivy Dodes
                                             Title: President

                                          CREDIT SUISSE FIRST BOSTON (EUROPE) 
                                          LIMITED


                                          By:  [Illegible]
                                             -----------------------------------
                                             Name:
                                             Title:


                                          By:  [Illegible]
                                             -----------------------------------
                                             Name:
                                             Title:



                                      -19-



                                          CHASE EQUITY ASSOCIATES, L.P.


                                          By: /s/ John M. B. O'Connor
                                             -----------------------------------
                                             Name:  John M. B. O'Connor
                                             Title: General Partners

                                          ENVIROSYSTEMS CORP.


                                          By: /s/ David J. Langevin
                                             -----------------------------------
                                             Name:  David J. Langevin
                                             Title: EVP CFO

                                          ENVIRONMENTAL SYSTEMS PRODUCTS 
                                          HOLDINGS INC.


                                          By: /s/ David J. Langevin
                                             -----------------------------------
                                             Name:  David J. Langevin
                                             Title: EVP CFO


                                      -20-



                                          GUARANTORS:

                                          ENVIRONMENTAL SYSTEMS PRODUCTS, 
                                          INC.


                                          By: /s/ Terrence McKenna
                                             -----------------------------------
                                             Name:  Terrence McKenna
                                             Title: President & CEO

                                          ENVIROTEST SYSTEMS CORP. (Delaware)


                                          By: /s/ Terrence McKenna
                                             -----------------------------------
                                             Name:  Terrence McKenna
                                             Title: President & CEO

                                          ENVIROTEST HOLDINGS, INC.


                                          By: /s/ Terrence McKenna
                                             -----------------------------------
                                             Name:  Terrence McKenna
                                             Title: President & CEO

                                          ENVIROTEST TECHNOLOGIES, INC.


                                          By: /s/ Terrence McKenna
                                             -----------------------------------
                                             Name:  Terrence McKenna
                                             Title: President & CEO

                                          ENVIROTEST PARTNERS


                                          By: /s/ Terrence McKenna
                                             -----------------------------------
                                             Name:  Terrence McKenna
                                             Title: President & CEO

                                          REMOTE SENSING TECHNOLOGIES, INC.


                                          By: /s/ Terrence McKenna
                                             -----------------------------------
                                             Name:  Terrence McKenna
                                             Title: President & CEO


                                      -21-



                                          ENVIROTEST WISCONSIN, INC.


                                          By: /s/ Terrence McKenna
                                             -----------------------------------
                                             Name:  Terrence McKenna
                                             Title: President & CEO

                                          ES FUNDING CORPORATION


                                          By: /s/ Terrence McKenna
                                             -----------------------------------
                                             Name:  Terrence McKenna
                                             Title: President & CEO

                                          ENVIROTEST ACQUISITIONS CO.


                                          By: /s/ Terrence McKenna
                                             -----------------------------------
                                             Name:  Terrence McKenna
                                             Title: President & CEO

                                          ENVIROTEST SYSTEMS CORP. (Washington)


                                          By: /s/ Terrence McKenna
                                             -----------------------------------
                                             Name:  Terrence McKenna
                                             Title: President & CEO

                                          ENVIROTEST ILLINOIS, INC.


                                          By: /s/ Terrence McKenna
                                             -----------------------------------
                                             Name:  Terrence McKenna
                                             Title: President & CEO

                                          NEWMALL LTD.


                                          By:   [Illegible]
                                             -----------------------------------
                                             Name:  
                                             Title: 


                                      -22-



                                          WELLMANN OVERSEAS LTD.


                                          By:  [Illegible]
                                             -----------------------------------
                                             Name:  
                                             Title: 


                                      -23-