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                                                                   Exhibit 10.12

                           AGREEMENT MODIFYING AND EXTENDING THE TOLL PROCESSING
                           AGREEMENT BETWEEN MSI AND SHAMROCK
                     -----------------------------------------------------------

         1) This is an extension of the existing Toll Processing 
Agreement.  The terms of such Agreement shall remain in full force and effect 
except as modified hereby.

         2) The Term of this Agreement shall be eighteen (18) months commencing
January 1, 1996 and expiring on June 30, 1997.

         3) This agreement can be further extended by Shamrock in three (3)
month increments until December 31, 1997 by giving MSI written notice ninety
(90) days prior to the commencement of the extended period.

         4) MSI shall provide Shamrock (and Shamrock guarantees the usage of)
5,000 Beam hours per twelve (12) month period. The volume shall be approximately
416 Beam hours per month for the length of the Agreement and Shamrock shall
deliver sufficient PTFE for processing so that the usage of the Beam shall be
approximately 416 Beam hours per month.

         4.1      The prices to be in effect during the extension period are:

Item                                    Price
----                                    -----
a)  Blender Irradiation                 $450 hr.
    (up to 150 Kilowatts per hr.)
b)  Tray Irradiation                    $ configured by the formula (Megarad 
                                        dose x $.0096 per pound) + $.15 per 
                                        pound x .75
c)  Chopping                            $.015 per lb.
d)  Grinding                            $.45 per lb.

         5) If Shamrock wishes to use more than 5,000 Beam hours per twelve
month period, they shall give MSI ninety (90) days written notice, and MSI will
discuss Shamrock's requirements based upon the availability of Beam time.

         5.1 If Shamrock uses additional hours over the 5,000 per year, the
billing rate on the additional hours shall be at a 20% premium over existing
prices of as follows.

              The prices per Beam hour shall be:

a)  Blender irradiation           $540 hr.
b)  Tray Irradiation              The formula price as set forth in 
                                  Paragraph 4.1(b) plus 20%

         6) MSI has occasional cyclical short term periods of underutilization
of its Beam during a month. MSI shall notify Shamrock of the availability of
such Beam time and at Shamrock's request shall make available such short term be
as set forth in Paragraph 4.1.

         7) MSI shall provide Shamrock with approximately 45,000 - 50,000 square
feet of space in its facility. The area basically referred to is the back of the
building, and Shamrock shall have discrete entrance areas.

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         7.1 MSI shall see to it that all property belonging to Dukal Corp.,
("Dukal") and/or MSI shall be cleared from Bay H3, I3, J3, and K1 on or before
November 15, 1995.

         7.2 MSI presently has a sublease with Dukal, which terminates on June
1, 1996. Prior to June 1, 1996, MSI will construct fencing to restrict the
access of Dukal's employees to the Shamrock teflon area. MSI agrees that it will
not extend its sublease with Dukal and will see to it that Dukal will vacate its
subleased space no later than June 1, 1996. After such space is vacated by
Dukal, it will be allocated to Shamrock for the teflon processing operation.

Agreed:                                   Agreed:

Medical Sterilization, Inc.               Shamrock Technologies, Inc.


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D. Michael Deignan            Date        Robert Luniewski                 Date