SECURITY AGREEMENT

  THIS SECURITY AGREEMENT is made and dated this 11th day of November,
1996, for the benefit of the registered holders of those certain 12% Secured
Promissory Notes (herein collectively called the "Secured Parties" and
individually a "Secured Party") in an aggregate principal amount not exceeding
one million dollars issued by VISTA TECHNOLOGIES INC., a Nevada corporation 
("Debtor") with its principal offices at 167 S. San Antonio Road, Suite 9, Los
Altos, California  94022.

  A.    Debtor has issued and sold 12% Secured Promissory Notes due June
30, 1997 or earlier upon the occurrence of certain events as set forth therein
(herein called the "Bridge Notes"), pursuant to which Secured Parties have
advanced loans to the Debtor on the terms and subject to the conditions set
forth therein.   All terms not otherwise defined herein are used with the same
meaning as set forth in the Bridge Notes.

  B.    As security for the payment and performance of its obligations to
the Secured Parties under the Bridge Notes and under this Security Agreement,
it is the intent of Debtor to pledge and to grant to Secured Party and create
a security interest in all of the assets of the Debtor, as hereinafter
provided, subject only to a first priority security interest of Pharma Patch
Plc in certain shares of Technical and Chemical Products Inc. common stock so
long as the same, or any portion thereof, are owned as an asset by the Debtor
and subject to purchase money equipment lease and installment note obligations
for the acquisition of laser vision correction equipment.

  NOW, THEREFORE, in consideration of the above Recitals and for other
good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, Debtor hereby agrees as follows:

  1.    GRANT OF SECURITY INTEREST.   Debtor hereby pledges and grants to
Secured Parties a security interest in the property described in Paragraph 2
below (collectively and severally, the "Collateral") to secure payment and
performance of the obligations of Debtor to the Secured Parties described in
Paragraph 3 below (collectively and severally, the "Obligations").

  2.    COLLATERAL.  The Collateral shall consist of the following assets
of the Debtor:

  (a)   All inventory of Debtor, now owned or hereafter acquired,
including, without limitation, all raw materials, work in process, materials
used or consumed in Debtor's business and finished goods, and merchandise,
parts and supplies of every kind, including inventory temporarily out of
Debtor's custody or possession, and all additions, accessions, improvements,
replacements and substitutions thereto and products thereof, together with all
returns on accounts;

  (b)   All goods and equipment of Debtor, now owned or hereafter
acquired, or in which Debtor now has or may hereafter acquire any interest,
including, without limitation, all machinery, supplies, tools, dies,
blueprints, catalogs, computer hardware and software, furniture, furnishings
and fixtures, motor vehicles of every kind and description, and all additions,
accessions, improvements, replacements and substitutions thereto and products
thereof;

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  (c)   All accounts, contract rights and general intangibles now owned or
hereafter created or acquired by Debtor, including, without limitation, all
receivables, goodwill, trademarks, trade styles, trade names, patents, patent
applications, software, customer lists and business records;

  (d)   All documents, instruments and chattel paper now owned or
hereafter acquired by Debtor;

  (e)   All monies, deposit accounts, certificates of deposit and
securities of Debtor now or hereafter in Secured Parties's or its agents'
possession including, without limitation, shares of Technical Chemicals and
Products Inc. common stock owned by the Debtor subject only to a first
priority security interest of Pharma Patch Plc in such shares of Technical and
Chemical Products Inc. common stock so long as the same, or any portion
thereof, are owned as an asset by the Debtor.

  (f)   All now existing and hereafter acquired books and records relating
to the foregoing Collateral and all now owned and hereafter acquired equipment
containing such books and records; and

  (g)   All proceeds of the foregoing Collateral.   For purposes of this
Security Agreement, the term "proceeds" includes whatever is receivable or
received when Collateral or proceeds is sold, collected, exchanged or
otherwise disposed of, whether such disposition is voluntary or involuntary,
and includes, without limitation, all rights to payment, including return
premiums, with respect to any insurance relating thereto.

  3.    OBLIGATIONS.  The Obligations of Debtor secured by this Security
Agreement shall consist of any and all debts, obligations and liabilities of
Debtor to Secured Parties under the terms and conditions of the Bridge Notes
including, without limitation, all rights to payment of principal, interest
and costs of collection set forth in the Bridge Notes and all obligations of
the Debtor in this Security Agreement and all amendments or extensions or
renewals of the Bridge Notes, and/or this Security Agreement, whether now
existing or hereafter and howsoever arising, voluntary or involuntary, whether
or not jointly owed with others, direct or indirect, absolute or contingent,
due or to become due, liquidated or unliquidated, and whether or not from time
to time decreased or extinguished and later increased, created or incurred.

  4.    SECURED PARTIES ACTION BY MAJORITY CONSENT.   Any action permitted
to be taken by the Securities Parties under this Agreement, and any notices
given by Securities Parties, shall require the written consent or approval of
at least a majority-in-interest of the unpaid principal represented by the
Bridge Notes evidenced by a writing executed by the registered holders
thereof.   Upon the request of any Secured Party, Debtor shall promptly
furnish to all Secured Parties a current listing of the names and addresses of
the registered holders of all of the Bridge Notes and the amount of
outstanding and principal represented by each of the same.

  5.    ADDITIONAL REPRESENTATIONS AND WARRANTIES.  Debtor hereby
represents and warrants that: (a) except as heretofore disclosed to Secured
Parties in writing, Debtor is the owner of the Collateral (or, in the case of
after-acquired Collateral, at the time Debtor acquires

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rights in the Collateral, will be the owner thereof) and that no other person
has (or, in the case of after-acquired Collateral, at the time Debtor acquires
rights therein, will have) any right, title, claim or interest (by way of
security interest or other lien or charge or otherwise) in, against or to the
Collateral, except for purchase equipment money lease and installment purchase
financing as to laser vision correction equipment and except for the security
interest of Pharma Patch Plc in shares of Technical Chemicals and Products
Inc., (b) all information heretofore, herein or hereafter supplied to Secured
Parties by or on behalf of Debtor with respect to the Collateral when supplied
was, is or will be true and correct, respectively; (c) each account, contract
right, item of chattel paper, instrument or any other right to the payment of
money constituting Collateral is genuine and enforceable in accordance with
its terms against the party obligated to pay the same (an "Account Debtor"),
which terms have not been modified or waived in any respect or to any extent; 
(d) the amount represented by Debtor to Secured Parties as owing by any
Account Debtor is the correct amount actually and unconditionally owing by
such Account Debtor, except for normal discounts where applicable; and (e) no
Account Debtor has any defense, set off, claim or counterclaim against Debtor
which can be asserted against Secured Parties, whether in any proceeding to
enforce Secured Parties's rights in the Collateral, or otherwise.

  6.    COVENANTS OF DEBTOR.  Debtor hereby agrees (a) to do all acts that
may be necessary to maintain, preserve and protect the Collateral;  (b) not to
use or permit any Collateral to be used unlawfully; (c) to pay promptly when
due all taxes, assessments, charges, encumbrances and liens now or hereafter
imposed upon or affecting any Collateral; (d) to notify Secured Parties
promptly of any change in Debtor's name or place of business, or, if Debtor
has more than one place of business, its head office, or office in which
Debtor's records relating to the Collateral are kept; (e) to procure, execute
and deliver from time to time any endorsements, assignments, financing
statements and other writings deemed necessary or appropriate by Secured
Parties to perfect, maintain and protect their security interest hereunder and
the priority thereof;  (f) to appear in and defend any action or proceeding
which may affect its title to or Secured Parties' interest in the Collateral;
(g) to keep separate, accurate and complete records of the Collateral and to
provide Secured Parties with such records and such other reports and
information relating to the Collateral as Secured Parties may request from
time to time; (h) not to surrender or lose possession of (other than to
Secured Parties), sell, encumber, lease, rent, or otherwise dispose of or
transfer any Collateral or right or interest therein except in the ordinary
course of Debtor's business and except that Debtor is authorized to sell the
Technical Chemical and Products Inc. common stock and to apply proceeds
thereof to payment of Debtor's obligations to Pharma Patch Plc and the holders
of the Bridge Notes as their interests shall appear, and to otherwise keep the
Collateral free of all levies and security interests or other liens or charges
except those contemplated by this Security Agreement or approved in writing by
Secured Parties; (i) to account fully for and promptly deliver to Secured
Parties, in the form received, all proceeds of the Collateral received,
endorsed to Secured Parties as appropriate, and until so delivered all
proceeds shall be held by Debtor in trust for Secured Parties, separate from
all other property of Debtor and identified as the property of Secured
Parties; (j) to keep the Collateral in good condition and repair; (k) not to
cause or permit any waste or unusual or unreasonable depreciation of the
Collateral; (l) at any reasonable time, upon demand by Secured Parties, to
exhibit to and allow inspection by Secured Parties (or persons designated by
Secured Parties) of the Collateral; (m) to keep the records concerning the
Collateral at the principal office

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of the Debtor in the State of California; and (m) to insure the Collateral,
with Secured Parties named as loss payee, in form and amounts, with companies,
and against risks and liabilities satisfactory to Secured Parties.

  7.    AUTHORIZED ACTION BY SECURED PARTIES.   In the event of a default
under the Bridge Notes, Debtor hereby irrevocably appoints Secured Parties as
the Debtor's attorney-in-fact to do (but Secured Parties shall not be
obligated to and shall incur no liability to Debtor or any third party for
failure so to do) any act which Debtor is obligated by this Security Agreement
to do, and to exercise such rights and powers as Debtor might exercise with
respect to the Collateral, including, without limitation, the right to (a)
collect by legal proceedings or otherwise and endorse, receive and receipt all
dividends, interest, payments, proceeds and other sums and property now or
hereafter payable on or on account of the Collateral;  (b) enter into any
extension or other agreement pertaining to, or deposit, surrender, accept,
hold or apply other property in exchange for the Collateral; (c) insure,
process and preserve the Collateral; (d) transfer the Collateral to its own or
its nominee's name; and (e) make any compromise or settlement, and take any
action it deems advisable, with respect to the Collateral.  Debtor agrees to
reimburse Secured Parties upon demand for any costs and expenses, including,
without limitation, attorneys' fees, Secured Parties may incur while acting as
Debtor's attorney-in-fact hereunder, all of which costs and expenses are
included in the Obligations secured hereby.

  8.    SALE OR LEASE OF COLLATERAL.   Until otherwise notified by Secured
Parties, Debtor may sell or lease Collateral consisting of inventory or
equipment in the ordinary course of Debtor's business and in the ordinary
course of business of any subsidiary corporations in which Debtor shall own an
equity interest.

  9.    NOTIFICATION OF ACCOUNT DEBTORS; COLLECTION.   In the event of a
default under the Bridge Notes, Debtor agrees that Secured Parties may at any
time, but shall not be obligated to, notify any Account Debtor on any Col-
lateral to make payment directly to Secured Parties.  Until otherwise notified
by Secured Parties, Debtor shall collect, enforce and receive delivery and
payment of the Collateral.

  10.   DEFAULT AND REMEDIES.  Debtor shall be deemed in default under
this Security Agreement upon the occurrence of any of the following (an "Event
of Default"):   (i) any representation or warranty of Debtor contained herein
or otherwise made in connection with the transactions contemplated hereby
shall be false or misleading in any material respect on the date as of which
made,  (ii) Debtor shall fail to perform any of the terms, provisions,
covenants, conditions, agreements or obligations contained in this Security
Agreement or (iii) an Event of Default shall occur under (and as defined in)
the Bridge Notes.   Upon the occurrence of any such Event of Default, Secured
Parties may, at their option, and without notice to or demand on Debtor and in
addition to all rights and remedies available to Secured Parties under the
Bridge Notes, do any one or more of the following:   (a) foreclose or
otherwise enforce Secured Parties' security interest in any manner permitted
by law, or provided for in this Security Agreement;  (b) sell, lease or
otherwise dispose of any Collateral at one or more public or private sales,
whether or not such Collateral is present at the place of sale, for cash or
credit or future delivery, on such commercially reasonable terms and in such
manner as Secured Parties may determine; (c) recover from Debtor all costs and
expenses, including, without limitation, reasonable attorneys' fees, incurred
or paid by Secured Parties in exercising any right, power

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or remedy provided by this Security Agreement or by law; (d) require Debtor to
assemble the Collateral and make it available to Secured Parties at a place to
be designated by Secured Parties;  (e) enter onto property where any
Collateral is located and take possession thereof with or without judicial
process;  (f) prior to the disposition of the Collateral, store, process,
repair or recondition it or otherwise prepare it for disposition in any manner
and to the extent Secured Parties deem appropriate; and (g) exercise any and
all other rights and remedies available to a secured party under the
California Uniform Commercial Code.

  11.   WAIVER OF HEARING.  Debtor expressly waives any constitutional or
other right to a judicial hearing prior to the time Secured Parties takes
possession or disposes of the Collateral upon default as provided herein.

  12.   WAIVER.   Any forbearance or delay by Secured Parties in
exercising any right, power or remedy shall not preclude the further exercise
thereof, and every right, power or remedy of Secured Parties shall continue in
full force and effect until such right, power or remedy is specifically waived
in a writing executed by Secured Parties.  Debtor waives any right to require
Secured Parties to proceed against any person or to exhaust any Collateral or
to pursue any remedy in Secured Parties's power.

  13.   BINDING UPON SUCCESSORS.  All rights of Secured Parties under this
Security Agreement shall inure to the benefit of their respective successors
and assigns, and all obligations of Debtor shall bind its heirs, executors,
administrators, successors and assigns.

  14.   ENTIRE AGREEMENT; SEVERABILITY.  The terms of this Security
Agreement are intended by the parties as a final expression of their agreement
with respect to such terms as are included in this Security Agreement and may
not be contradicted by evidence of any prior or contemporaneous agreement. 
The parties' further intend that this Security Agreement constitutes the
complete and exclusive statement of its terms and that no extrinsic evidence
whatsoever may be introduced in any judicial proceeding, if any, involving
this Security Agreement.  If any of the provisions of this Security Agreement
shall be held invalid or unenforceable, this Security Agreement shall be
construed as if not containing those provisions and the rights and obligations
of the parties hereto shall be construed and enforced accordingly.

  15.   CHOICE OF LAW.   This Security Agreement shall be construed in
accordance with and governed by the laws of the State of California, and,
where applicable and except as otherwise defined herein, terms used herein
shall have the meanings given them in the California Uniform Commercial Code.

  EXECUTED as of this 11th day of November, 1996 in the City of Los Altos,
State of California.

"Debtor"            VISTA TECHNOLOGIES INC.

              By: /s/  Thomas A. Schultz
                  ------------------------------
                    Thomas A. Schultz, President



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