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                                                                    EXHIBIT 10.4

                            NONSTATUTORY STOCK OPTION

________________________, Optionee:

         Steritech, Inc. (the "Company"), pursuant to its 1996 Equity
Incentive Plan (the "Plan"), has granted to you, the optionee named above, an
option to purchase shares of the common stock of the Company ("Common Stock").
This option is not intended to qualify and will not be treated as an "incentive
stock option" within the meaning of Section 422 of the Internal Revenue Code of
1986, as amended (the "Code").

         The details of your option are as follows:

         1.       TOTAL NUMBER OF SHARES SUBJECT TO THIS OPTION. The total
number of shares of Common Stock subject to this option is ___________________
(_______).

         2.       VESTING. Subject to the limitations contained herein,
__________ [fraction or percentage (e.g., 25% or 12/48ths)] of the shares will
vest (become exercisable) on ____________, 19__ and __________ of the shares
will then vest each ____________ [month/year] thereafter until either (i) you
cease to provide services to the Company for any reason, or (ii) this option
becomes fully vested.

         3.       EXERCISE PRICE AND METHOD OF PAYMENT.

                  (A)      EXERCISE PRICE. The exercise price of this option is
_________________ ($____________) per share, being not less than 85% of the fair
market value of the Common Stock on the date of grant of this option.

                  (B)      METHOD OF PAYMENT. Payment of the exercise price per
share is due in full upon exercise of all or any part of each installment which
has accrued to you. You may elect, to the extent permitted by applicable
statutes and regulations, to make payment of the exercise price under one of the
following alternatives:

                           (I)      Payment of the exercise price per share in
cash (including check) at the time of exercise; or

                           (II)     Payment pursuant to a program developed
under Regulation T as promulgated by the Federal Reserve Board which, prior to
the issuance of Common Stock, results in either the receipt of cash (or check)
by the Company or the receipt of irrevocable instructions to pay the aggregate
exercise price to the Company from the sales proceeds.

         4.       WHOLE SHARES. This option may not be exercised for any number
of shares which would require the issuance of anything other than whole shares.

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         5.       SECURITIES LAW COMPLIANCE. Notwithstanding anything to the
contrary contained herein, this option may not be exercised unless the shares
issuable upon exercise of this option are then registered under the Act or, if
such shares are not then so registered, the Company has determined that such
exercise and issuance would be exempt from the registration requirements of the
Act.

         6.       TERM. The term of this option commences on ___________, 19__,
the date of grant, and expires on _____________________ (the "Expiration Date,"
which date shall be no more than ten (10) years from the date this option is
granted), unless this option expires sooner as set forth below or in the Plan.
In no event may this option be exercised on or after the Expiration Date. This
option shall terminate prior to the Expiration Date as follows: three (3) months
after the termination of your Continuous Status as an Employee, Director or
Consultant with the Company or an Affiliate of the Company (as defined in the
Plan) for any reason or for no reason unless:

                  (A)      such termination of Continuous Status as an Employee,
Director or Consultant is due to your disability, in which event the option
shall expire on the earlier of the Expiration Date set forth above or twelve
(12) months following such termination of Continuous Status as an Employee,
Director or Consultant; or

                  (B)      such termination of Continuous Status as an Employee,
Director or Consultant is due to your death or your death occurs within ________
[days/months] following your termination for any other reason, in which event
the option shall expire on the earlier of the Expiration Date set forth above or
eighteen (18) months after your death; or

                  (C)      during any part of such _________ [day/month] period
the option is not exercisable solely because of the condition set forth in
paragraph 5 above, in which event the option shall not expire until the earlier
of the Expiration Date set forth above or until it shall have been exercisable
for an aggregate period of three (3) months after the termination of Continuous
Status as an Employee, Director or Consultant; or

                  (D)      exercise of the option within following termination
of your Continuous Status as an Employee, Director or Consultant with the
Company or with an Affiliate would result in liability under section 16(b) of
the Securities Exchange Act of 1934 (the "Exchange Act"), in which case the
option will expire on the earlier of (i) the Expiration Date set forth above,
(ii) the tenth (10th) day after the last date upon which exercise would result
in such liability or (iii) six (6) months and ten (10) days after the
termination of your Continuous Status as an Employee, Director or Consultant
with the Company or an Affiliate.

         However, this option may be exercised following termination of
Continuous Status as an Employee, Director or Consultant only as to that number
of shares as to which it was exercisable on the date of termination of
Continuous Status as an Employee, Director or Consultant under the provisions of
paragraph 2 of this option.

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         7.       REPRESENTATION. By executing this option agreement, you hereby
warrant and represent that you are acquiring this option for your own account
and that you have no intention of distributing, transferring or selling all or
any part of this option except in accordance with the terms of this option
agreement.

         8.       EXERCISE.

                  (A)      This option may be exercised, to the extent specified
above, by delivering a notice of exercise (in a form designated by the Company)
together with the exercise price to the Secretary of the Company, or to such
other person as the Company may designate, during regular business hours,
together with such additional documents as the Company may then require.

                  (B)      By exercising this option you agree that:

                           (I)      as a precondition to the completion of any
exercise of this option, the Company may require you to enter an arrangement
providing for the cash payment by you to the Company of any tax withholding
obligation of the Company arising by reason of: (1) the exercise of this option;
(2) the lapse of any substantial risk of forfeiture to which the shares are
subject at the time of exercise; or (3) the disposition of shares acquired upon
such exercise. You also agree that any exercise of this option has not been
completed and that the Company is under no obligation to issue any Common Stock
to you until such an arrangement is established or the Company's tax withholding
obligations are satisfied, as determined by the Company; and

                           (II)     the Company (or a representative of the
underwriters) may, in connection with the first underwritten registration of the
offering of any securities of the Company under the Act, require that you not
sell or otherwise transfer or dispose of any shares of Common Stock or other
securities of the Company during such period (not to exceed one hundred eighty
(180) days) following the effective date (the "Effective Date") of the
registration statement of the Company filed under the Act as may be requested by
the Company or the representative of the underwriters. You further agree that
the Company may impose stop-transfer instructions with respect to securities
subject to the foregoing restrictions until the end of such period.

         9.       TRANSFERABILITY. This option is not transferable, except by
will or by the laws of descent and distribution or pursuant to a domestic
relations order satisfying the requirements of Rule 16b-3 (a "QDRO"), and is
exercisable during your life only by you or a transferee pursuant to a QDRO.
Notwithstanding the foregoing, by delivering written notice to the Company, in a
form satisfactory to the Company, you may designate a third party who, in the
event of your death, shall thereafter be entitled to exercise this option.

         10.      OPTION NOT A SERVICE CONTRACT. This option is not an
employment contract and nothing in this option shall be deemed to create in any
way whatsoever any obligation on your part to continue in the employ of the
Company, or of the Company to continue your

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employment with the Company. In addition, nothing in this option shall obligate
the Company or any Affiliate, or their respective stockholders, Board of
Directors, officers or employees to continue any relationship which you might
have as a Director or Consultant for the Company or Affiliate.

         11.      NOTICES. Any notices provided for in this option or the Plan
shall be given in writing and shall be deemed effectively given upon receipt or,
in the case of notices delivered by the Company to you, five (5) days after
deposit in the United States mail, postage prepaid, addressed to you at the
address specified below or at such other address as you hereafter designate by
written notice to the Company.

         12.      GOVERNING PLAN DOCUMENT. This option is subject to all the
provisions of the Plan, a copy of which is attached hereto and its provisions
are hereby made a part of this option, including without limitation the
provisions of Section 6 of the Plan relating to option provisions, and is
further subject to all interpretations, amendments, rules and regulations which
may from time to time be promulgated and adopted pursuant to the Plan. In the
event of any conflict between the provisions of this option and those of the
Plan, the provisions of the Plan shall control.

         Dated the ____ day of __________________, 19__.

                                Very truly yours,


                                _______________________________________________


                                By_____________________________________________
                                  Duly authorized on behalf
                                  of the Board of Directors

ATTACHMENTS:

         Company's 1996 Equity Incentive Plan
         Notice of Exercise

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The undersigned:

         (A)      Acknowledges receipt of the foregoing option and the
attachments referenced therein and understands that all rights and liabilities
with respect to this option are set forth in the option and the Plan; and

         (B)      Acknowledges that as of the date of grant of this option, it
sets forth the entire understanding between the undersigned optionee and the
Company and its Affiliates regarding the acquisition of stock in the Company and
supersedes all prior oral and written agreements on that subject with the
exception of (i) the options previously granted and delivered to the undersigned
under stock option plans of the Company, and (ii) the following agreements only:

         NONE   _______________________
                (Initial)

         OTHER  _______________________

                _______________________

                _______________________


                                     __________________________________________
                                     OPTIONEE

                                     Address:__________________________________

                                             __________________________________

                                       5.
