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                                                                EXHIBIT 10(o)(3)

                       THIRD AMENDMENT TO INDUSTRIAL LEASE
          10400 AND 10410 TRADEMARK STREET, RANCHO CUCAMONGA, CA 91730


         1.       The terms of the industrial lease dated March 18, 1991
originally between Rancho Cucamonga Business Park as Lessor and U.S. Alcohol
Testing of America as Lessee and currently by and between Substance Abuse
Technologies, Inc. (formerly U.S. Alcohol Testing of America) as Lessee and the
Realty Trust as Lessor is amended as follows:

         2.       The monthly rentals for the first option period exercised by
Lessee shall be amended as follows:

         February 1, 1997 to January 31, 1998  $10,750.00

         February 1, 1998 to January 31, 1999  $11,072.50

         February 1, 1999 to January 31, 2000  $11,404.68

         February 1, 2001 to January 21, 2002  $12,099.11

         3.       All other terms and conditions of the original lease dated
March 18, 1991 and its addendum and amendments shall remain in full force and
effect.

         4.       This Third Amendment is executed in two (2) originals. One
original shall be held by the Lessor, the Realty Trust, and one original shall
be held by the Lessee, Substance Abuse Technologies, Inc.

Dated:  January 2, 1997

                                          SUBSTANCE ABUSE TECHNOLOGIES, INC.


                                          By: /s/ Linda H. Masterson
                                              ------------------------------
                                              Linda H. Masterson, President


Dated:  December 30, 1996

                                          THE REALTY TRUST

                                          By: /s/ Simi Dabah
                                              ------------------------------
                                              Simi Dabah, Trustee


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