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                                                                    EXHIBIT 10.6



                                TRUST AGREEMENT
                                      FOR
                         AMERICAN PACIFIC CORPORATION
                    SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN

This Agreement made this  23/rd/ day of     November, 1999       , by and
                         ------          ------------------------
between American Pacific Corporation (the "Company") and John R. Gibson and
David N. Keys (collectively the "Trustee").

WHEREAS, the Company has adopted the American Pacific Corporation Supplemental
Executive Retirement Plan;

WHEREAS, the Company has incurred or expects to incur liability under the terms
of such Plan with respect to the individuals participating in such Plan;

WHEREAS, the Company wishes to establish a trust (the "Trust") and, at its
discretion, or pursuant to the terms of the Plan, to contribute to the Trust
assets that shall be held therein, subject to the claims of the Company's
creditors in the event of the Company's Insolvency, as herein defined, until
paid to Plan participants and their beneficiaries in such manner and at such
times as specified in the Plan;

WHEREAS, it is the intention of the parties that this Trust shall constitute an
unfunded arrangement and shall not affect the status of the Plan as an unfunded
plan maintained for the purpose of providing deferred compensation for a select
group of management or highly-compensated employees for purposes of Title I of
the Employee Retirement Income Security Act of 1974;

WHEREAS, it is the intention of the Company to make contributions to the Trust
to provide itself with a source of funds to assist it in the meeting of its
liabilities under the Plan;

NOW, THEREFORE, the parties do hereby establish the Trust and agree that the
Trust shall be comprised, held and disposed of as follows:

                              Exhibit 10.6 Page 1
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SECTION 1. Establishment of Trust.
           ----------------------

      (a)  The Company hereby deposits with the Trustee in trust
           $ 1.6 million    , which shall become the principal of the Trust to
            ----------------
           be held, administered and disposed of by the Trustee as provided in
           this Trust Agreement.

      (b)  The Trust hereby established shall be irrevocable.

      (c)  The Trust is intended to be a grantor trust, of which the Company is
           the grantor, within the meaning of subpart E, part I, subchapter J,
           chapter 1, subtitle A of the Internal Revenue Code of 1986, as
           amended, and shall be construed accordingly.

           (d) The principal of the Trust, and any earnings thereon shall be
           held separate and apart from other funds of the Company and shall be
           used exclusively for the uses and purposes of Plan participants and
           general creditors as herein set forth.  Plan participants and their
           beneficiaries shall have no preferred claim on, or any beneficial
           ownership interest in, any assets of the Trust.  Any rights created
           under the Plan and this Trust Agreement shall be mere unsecured
           contractual rights of Plan participants and their beneficiaries
           against the Company.  Any assets held by the Trust will be subject to
           the claims of the Company's general creditors under federal and state
           law in the event of Insolvency, as defined in Section 3(a) herein.

      (e)  The Company may at any time, or from time to time, make additional
           deposits of cash or other property in trust with the Trustee to
           augment the principal to be held, administered and disposed of by the
           Trustee as provided in this Trust Agreement.  Prior to a Change of
           Control neither the Trustee nor any Plan participant or beneficiary
           shall have any right to compel such additional deposits.

                              Exhibit 10.6 Page 2
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      (f)  Upon a Change of Control, the Company shall, as soon as possible, but
           in no event longer than 30 days following the Change of Control, as
           defined herein, make an irrevocable contribution to the Trust in an
           amount that is sufficient to pay each Plan participant or beneficiary
           the benefits to which Plan participants or their beneficiaries would
           be entitled pursuant to the terms of the Plan as of the date on which
           the Change of Control occurred.

SECTION 2. Payments to the Plan Participants and Their Beneficiaries.
           ---------------------------------------------------------

      (a)  The Company shall deliver to the Trustee a schedule (the "Payment
           Schedule") that indicates the amounts payable in respect of each Plan
           participant (and his or her beneficiaries), provides a formula or
           other instructions acceptable to the Trustee for determining the
           amounts so payable, specifies the form in which such amounts are to
           be paid (as provided for or available under the Plan), and specifies
           the time of commencement for payment of such amounts.  Except as
           otherwise provided herein, the Trustee shall make payments to the
           Plan participants and their beneficiaries in accordance with such
           Payment Schedule.  The Trustee shall make provision for the reporting
           and withholding of any federal, state or local taxes that may be
           required to be withheld with respect to benefits pursuant to the
           terms of the Plan and shall pay amounts withheld to the appropriate
           taxing authorities or determine that such amounts have been reported,
           withheld and paid by the Company.

      (b)  The entitlement of a Plan participant or his or her beneficiaries to
           benefits under a Plan shall be determined by the Company or such
           party as it shall designate under the Plan, and any claim for such
           benefits shall be considered and reviewed under the procedures set
           out in the Plan.

      (c)  The Company may make payment of benefits directly to Plan
           participants or their beneficiaries as they become due under the
           terms of the Plan.  The Company shall notify the Trustee of its
           decision to make payment of benefits directly prior to the time
           amounts are payable to participants or their

                              Exhibit 10.6 Page 3
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           beneficiaries. In addition, if the principal of the Trust, and any
           earnings thereon, are not sufficient to make payments of benefits in
           accordance with the terms of the Plan, the Company shall make the
           balance of each such payment as it falls due. The Trustee shall
           notify the Company where principal and earnings are not sufficient.

SECTION 3. Trustee Responsibility Regarding Payments to Trust Beneficiary When
           -------------------------------------------------------------------
           the Company is Insolvent.
           ------------------------

     (a)   The Trustee shall cease payment of benefits to Plan participants and
           their beneficiaries if the Company is Insolvent.  The Company shall
           be considered "Insolvent" for purposes of this Trust Agreement if (i)
           the Company is unable to pay its debts as they become due, or (ii)
           the Company is subject to a pending proceeding as a debtor under the
           United States Bankruptcy Code.

      (b)  At all times during the continuance of this Trust, as provided in
           Section 1(d) hereof, the principal and income of the Trust shall be
           subject to claims of general creditors of the Company under federal
           and state law as set forth below.

           (1)  The Board of Directors and the Chief Executive Officer of the
                Company shall have the duty to inform the Trustee in writing of
                the Company's Insolvency.  If a person claiming to be a creditor
                of the Company alleges in writing to the Trustee that the
                Company has become Insolvent, the Trustee shall determine
                whether the Company is Insolvent and, pending such
                determination, the Trustee shall discontinue payment of benefits
                to Plan participants or their beneficiaries.

           (2)  Unless the Trustee has actual knowledge of the Company's
                Insolvency, or has received notice from the Company or a person
                claiming to be a creditor alleging that the Company is
                Insolvent, the Trustee shall have no duty to inquire whether the
                Company is Insolvent.  The Trustee may in all events rely on
                such evidence concerning the Company's solvency as may be
                furnished to the Trustee and that provides the Trustee with a

                              Exhibit 10.6 Page 4
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                reasonable basis for making a determination concerning the
                Company's solvency.

           (3)  If at any time the Trustee has determined that the Company is
                Insolvent, the Trustee shall discontinue payments to Plan
                participants or their beneficiaries and shall hold the assets of
                the Trust for the benefit of the Company's general creditors.
                Nothing in this Trust Agreement shall in any way diminish any
                rights of Plan participants or their beneficiaries to pursue
                their rights as general creditors of the Company with respect to
                benefits due under a Plan or otherwise.

           (4)  The Trustee shall resume the payment of benefits to Plan
                participants or their beneficiaries in accordance with Section 2
                of this Trust Agreement only after the Trustee has determined
                that the Company is not Insolvent (or is no longer Insolvent).

     (c)  Provided that there are sufficient assets, if the Trustee discontinues
          the payment of benefits from the Trust pursuant to Section 3(b) hereof
          and subsequently resumes such payments, the first payment following
          such discontinuance shall include the aggregate amount of all payments
          due to Plan participants or their beneficiaries under the terms of the
          Plan for the period of such discontinuance, less the aggregate amount
          of any payments made to Plan participants or their beneficiaries by
          the Company in lieu of the payments provided for hereunder during any
          such period of discontinuance.

SECTION 4.  Payments to the Company.
            -----------------------

      Except as provided in Section 3 hereof, after the Trust has become
      irrevocable, the Company shall have no right or power to direct the
      Trustee to return to the Company or to divert to others any of the Trust
      assets before all payment of benefits have been made to Plan participants
      and their beneficiaries pursuant to the terms of the Plan.

SECTION 5.  Investment Authority.
            --------------------

                              Exhibit 10.6 Page 5
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      The Trustee may invest in securities (including stock or rights to acquire
      stock) or obligations issued by the Company.  All rights associated with
      assets of the Trust shall be exercised by the Trustee or the person
      designated by the Trustee, and shall in no event be exercisable by or rest
      with Plan participants.

      The Company shall have the right at anytime, and from time to time in its
      sole discretion, to substitute assets of equal fair market value for any
      asset held by the Trust.  This right is exercisable by the Company in a
      nonfiduciary capacity without the approval or consent of any person in a
      fiduciary capacity.

SECTION 6.  Disposition of Income.
            ---------------------

      During the term of this Trust, all income received by the Trust, net of
      expenses and taxes, shall be accumulated and reinvested.

SECTION 7.  Accounting by Trustee.
            ---------------------

      The Trustee shall keep accurate and detailed records of all investments,
      receipts, disbursements, and all other transactions required to be made,
      including such specific records as shall be agreed upon in writing between
      the Company and the Trustee.  Within 60  days following the close of each
      calendar year and within 60  days after the removal or resignation of the
      Trustee, the Trustee shall deliver to the Company a written account of its
      administration of the Trust during such year or during the period from the
      close of the last preceding year to the date of such removal or
      resignation, setting forth all investments, receipts, disbursements and
      other transactions effected by it, including a description of all
      securities and investments purchased and sold with the cost or net
      proceeds of such purchases or sales (accrued interest paid or receivable
      being shown separately), and showing all cash, securities and other
      property held in the Trust at the end of such year or as of the date of
      such removal or resignation, as the case may be.

SECTION 8.  Responsibility of Trustee.
            -------------------------

                              Exhibit 10.6 Page 6
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      (a)    The Trustee shall act with the care, skill, prudence and diligence
             under the circumstances then prevailing that a prudent person
             acting in like capacity and familiar with such matters would use in
             the conduct of an enterprise of a like character and with like
             aims, provided, however, that the Trustee shall incur no liability
             to any person for any action taken pursuant to a direction, request
             or approval given by the Company which is contemplated by, and in
             conformity with, the terms of a Plan or this Trust and is given in
             writing by the Company. In the event of a dispute between the
             Company and a party, the Trustee may apply to a court of competent
             jurisdiction to resolve the dispute.

      (b)    If the Trustee undertakes or defends any litigation arising in
             connection with this Trust, the Company agrees to indemnify the
             Trustee against the Trustee's costs, expenses and liabilities
             (including, without limitation, attorneys' fees and expenses)
             relating thereto and to be primarily liable for such payments. If
             the Company does not pay such costs, expenses and liabilities in a
             reasonably timely manner, the Trustee may obtain payment from the
             Trust.

      (c)    The Trustee may consult with legal counsel (who may also be counsel
             for the Company generally) with respect to any of its duties or
             obligations hereunder.

      (d)    The Trustee may hire agents, accountants, actuaries, investment
             advisors, financial consultants or other professionals to assist it
             in performing any of its duties or obligations hereunder.

      (e)    The Trustee shall have, without exclusion, all powers conferred on
             the Trustees by applicable law, unless expressly provided otherwise
             herein, provided, however, that if an insurance policy is held as
             an asset of the Trust, the Trustee shall have no power to name a
             beneficiary of the policy other than the Trust, to assign the
             policy (as distinct from conversion of the policy to a different
             form) other than to a successor the Trustee, or to loan to any
             person the proceeds of any borrowing against such policy.

                              Exhibit 10.6 Page 7
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      (f)    However, notwithstanding the provisions of Section 8(e) above, the
             Trustee may loan to the Company the proceeds of any borrowing
             against an insurance policy held as an asset of the Trust.

      (g)    Notwithstanding any powers granted to the Trustee pursuant to this
             Trust Agreement or to applicable law, the Trustee shall not have
             any power that could give this Trust the objective of carrying on a
             business and dividing the gains therefrom, within the meaning of
             section 301.7701-2 of the Procedure and Administrative Regulations
             promulgated pursuant to the Internal Revenue Code.

SECTION 9.   Compensation and Expenses of Trustee.
             ------------------------------------

     The Company shall pay all administrative and Trustee's fees and expenses.
     If not so paid, the fees and expenses shall be paid from the Trust.

SECTION 10.  Resignation and Removal of Trustee.
             ----------------------------------

      (a)    Prior to a Change of Control, the Trustee may resign at anytime by
             written notice to the Company, which shall be effective 30 days
             after receipt of such notice unless the Company and the Trustee
             agree otherwise. Following a Change of Control, the Trustee may
             resign only after the appointment of a successor Trustee.

      (b)    The Trustee may be removed by the Company on 30 days notice or upon
             shorter notice accepted by the Trustee. The Trustee may not be
             removed by the Company for one year following the Change of Control
             unless such removal is with the consent of a majority of the
             participants and such removal shall be effective only after a
             successor Trustee has been appointed pursuant to Section 11.

      (c)    Upon resignation or removal of  and appointment of a successor
             Trustee, all assets shall subsequently be transferred to the
             successor Trustee.  The transfer

                              Exhibit 10.6 Page 8
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             shall be completed within 90 days after receipt of notice of
             resignation, removal or transfer, unless the Company extends the
             time limit.

SECTION 11.  Appointment of Successor.
             ------------------------

      (a)    If the Trustee resigns (or is removed) prior to a Change of
             Control, the Company shall appoint a third party, such as a bank
             trust department or other party that has been granted corporate
             trustee powers under state law, as a successor to replace the
             Trustee upon resignation or removal. The appointment shall be
             effective when accepted in writing by the new Trustee, who shall
             have all of the rights and powers of the former Trustee, including
             ownership rights in the Trust assets. The former Trustee shall
             execute any instrument necessary or reasonably requested by the
             Company or the successor Trustee to evidence the transfer. If no
             such appointment has been made, the Trustee shall apply to a court
             of competent jurisdiction for appointment of a successor or for
             instructions. All expenses of the Trustee in connection with the
             proceeding shall be allowed as administrative expenses of the
             Trust.

      (b)    If the Trustee resigns (or is removed) coincident with or after a
             Change of Control, the Trustee shall appoint a third party, such as
             a bank trust department or other party that has been granted
             corporate trustee powers under state law, as a successor to replace
             the Trustee upon resignation or removal. The appointment shall be
             effective when accepted in writing by the new Trustee, who shall
             have all of the rights and powers of the former Trustee, including
             ownership rights in the Trust assets. The former Trustee shall
             execute any instrument necessary or reasonably requested by the
             successor Trustee to evidence the transfer. If no such appointment
             has been made, a majority of the participants may apply to a court
             of competent jurisdiction for appointment of a successor or for
             instructions. All expenses of the Trustee in connection with the
             proceeding shall be allowed as administrative expenses of the
             Trust.

                              Exhibit 10.6 Page 9
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      (c)    The successor Trustee need not examine the records and acts of any
             prior Trustee and may retain or dispose of existing Trust assets,
             subject to Section 7 and 8 hereof. The successor Trustee shall not
             be responsible for and the Company shall indemnify and defend the
             successor Trustee from any claim or liability resulting from any
             action or inaction of any prior Trustee or from any other past
             event, or any condition existing at the time it becomes a successor
             Trustee.

SECTION 12.  Amendment or Termination.
             ------------------------

      (a)    This Trust Agreement may be amended by a written instrument
             executed by the Trustee and the Company. Notwithstanding the
             foregoing, no such amendment shall conflict with the terms of the
             Plan or make the Trust revocable.

      (b)    The Trust shall not terminate until the date on which Plan
             participants and their beneficiaries are no longer entitled to
             benefits pursuant to the terms of the Plan. Upon termination of the
             Trust any assets remaining in the Trust shall be returned to the
             Company.

      (c)    Upon written approval of all participants or, in the case of a
             deceased participant, his beneficiaries, entitled to payment of
             benefits pursuant to the terms of a Plan, the Company may terminate
             this Trust prior to the time all benefit payments under the Plan
             have been made. All assets in the Trust at termination shall be
             returned to the Company.

      (d)    This Trust shall not be amended by the Company for one year
             following a Change of Control as defined herein without the written
             consent of a majority of the participants.

SECTION 13.  Miscellaneous.
             --------------

                             Exhibit 10.6 Page 10
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     (a)   Any provision of this Trust Agreement prohibited by law shall be
           ineffective to the extent of any such prohibition, without
           invalidating the remaining provisions hereof.

     (b)   Benefits payable to Plan participants and their beneficiaries under
           this Trust Agreement may not be anticipated, assigned (either at law
           or in equity), alienated, pledged, encumbered or subjected to
           attachment, garnishment, levy, execution or other legal or equitable
           process.

      (c)  This Trust Agreement shall be governed by and construed in accordance
           with the laws of the State of Delaware, to the extent not superseded
           by Federal law.

      (d)  For the purposes of this Trust, Change of Control shall mean

          (i)   a merger or consolidation of the Company with or into any other
                entity unless after such event at least a majority of the voting
                power of the surviving or resulting entity is beneficially owned
                by persons who beneficially own a majority of the voting power
                of the Company immediately prior to such event, or

          (ii)  the sale of fifty percent (50%) or more of the voting stock of
                the Company, or

          (iii) any "person" (as such term is used in Sections 13(d) and 14(d)
                of the Securities and Exchange Act of 1934, as amended (the
                "Exchange Act")) is or becomes the "beneficial owner" (as
                defined in Rules 13d-3 and 13d-5 under the Exchange Act, except
                that for purposes of this clause, such person shall be deemed to
                have "beneficial ownership" of all shares that any such person
                has the right to acquire, whether such right is exercisable
                immediately or only after the passage of time) directly or
                indirectly, of more than 35% of the total voting power of the
                voting stock of the Company, or

                             Exhibit 10.6 Page 11
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          (iv)  the sale of all or substantially all the assets of the Company,
                or

          (v)   the dissolution of the Company, or

          (vi)  a change in the identity of a majority of the members of the
                Company's board of directors within any twelve-month period,
                which change or changes are not recommended by the incumbent
                directors determined immediately prior to any such change or
                changes.

SECTION 14.  Effective Date.
             --------------

      The effective date of this Trust Agreement shall be    January 1, 1999.
                                                          ---------------------

                             Exhibit 10.6 Page 12
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IN WITNESS WHEREOF, American Pacific Corporation and the Trustee have executed
this Agreement as of the date first above written.

                              AMERICAN PACIFIC CORPORATION

                              By:    /s/ Linda G. Ferguson
                                   -------------------------------------
                              Its:  Vice President - Administration

Attest                        (Trustee)

_______________________       By:    /s/ David N. Keys
                                   -------------------

                              By:    /s/ John R. Gibson
                                   --------------------

                             Exhibit 10.6 Page 13