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                                                                     EXHIBIT 4.2





                                 May 16, 2001



To:      [Optionee Name]
         [Optionee Address]
         [Optionee Address]
         [Optionee Address]


         We are pleased to inform you that on April 24, 2001, the Board of
Directors of American Pacific Corporation (the "Company") granted you a
Nonqualified Option (the "Option") to purchase [Option Amount] shares of common
stock (the "Shares"), $.10 par value per share, of the Company ("Common Stock")
pursuant to the Company's 2001 Stock Option Plan (the "Plan"), at a price of
$4.87 per Share. Capitalized terms used herein and not otherwise defined shall
have the meanings ascribed to them in the Plan (a copy of which in its present
form is attached hereto).

         The Option may be exercised at any time or from time to time (a) with
respect to 50% of the Shares, on or after the date hereof (b) with respect to
the balance of the Shares, on or after the first anniversary of the date hereof
and, in any case, at or before 5:00 p.m., Las Vegas, Nevada time, on April 24,
2011 (the date on which the Option will, to the extent not previously exercised,
expire). You must purchase a minimum of 100 Shares each time you choose to
purchase Shares, except to purchase the remaining Shares available to you. In
the event of a change in control of the Company, the Committee may cause all or
part of the Option granted hereby to immediately become fully vested and
exercisable and/or may cause the Option to terminate within a specified number
of days after notice to you. The term "change in control" is defined in the Plan
and means, generally, consummation of (i) a tender offer for more than 30% of
the Company's voting securities, (ii) a merger or consolidation of the Company
with another corporation, (iii) the sale of all or substantially all of the
Company's assets, or (iv) the acquisition by a person or entity of 50% or more
of the Company's outstanding voting securities (unless, as a result of any such
transaction, more than 50% of the outstanding voting securities of the surviving
or resulting corporation (in the case of a transaction referred to in clause
(i), (ii), or (iv) above) or of the Company's assets (in the case of a
transaction referred to in clause (iii) above) shall be owned by shareholders of
the Company immediately prior to such transaction and/or Company benefit plans
and affiliates).

         The Option is issued in accordance with and is subject to and
conditioned upon all of the terms and conditions of the Plan, as from time to
time amended, provided, however, that no future amendment or termination of the
Plan shall, without your consent, alter or impair any of your rights or
obligations under the Option. Reference is made to the terms and conditions of
the Plan, all of which are incorporated by reference herein as if fully set
forth herein.

         The Company, in its sole discretion, may file a registration statement
under the Securities Act of 1933, as amended (the "Act"), in order to register
the Shares. Unless at the time of the exercise of the Option a registration
statement under the Act is in effect as to such Shares, any Shares purchased by
you upon the exercise of the Option shall be acquired for investment and not for
sale or distribution, and if the Company so requests, upon any exercise of the
Option, in whole or in part, you will execute and deliver to the Company a
certificate to such effect. The Company shall not be obligated to issue any
Shares pursuant to the Option if, in the opinion of counsel to the Company, the
Shares to be so issued are required to be registered or otherwise qualified
under the Act or under any other applicable statute, regulation or ordinance
affecting the sale of securities, unless and until such Shares have been so
registered or otherwise qualified.
<PAGE>

[Optionee Name]
May 16, 2001
Page 2

         You understand and acknowledge that, under existing law, unless at the
time of the exercise of the Option a registration statement under the Act is in
effect as to such Shares (i) any Shares purchased by you upon exercise of the
Option may be required to be held indefinitely unless such Shares are
subsequently registered under the Act or an exemption from such registration is
available; (ii) any sales of such Shares made in reliance upon Rule 144
promulgated under the Act may be made only in accordance with the terms and
conditions of that Rule (which, under certain circumstances, restrict the number
of shares which may be sold and the manner in which shares may be sold); (iii)
in the case of securities to which Rule 144 is not applicable, compliance with
some other disclosure exemption will be required before any Shares may be sold;
(iv) certificates for Shares to be issued to you hereunder shall bear a legend
to the effect that the Shares have not been registered under the Act and that
the Shares may not be sold, hypothecated or otherwise transferred in the absence
of an effective registration statement under the Act relating thereto or an
opinion of counsel satisfactory to the Company that such registration is not
required; (v) the Company will place an appropriate "stop transfer" order with
its transfer agent with respect to such Shares; and (vi) the Company has
undertaken no obligation to register the Shares or to include the Shares in any
registration statement which may be filed by it subsequent to the issuance of
the Shares to you.

         The Option (or installment thereof) is to be exercised by delivering to
the Company a written notice of exercise in the form attached hereto as Exhibit
A, specifying the number of Shares to be purchased, together with payment of the
purchase price of the Shares to be purchased. The purchase price is to be paid
in cash, certified check or, at the discretion of the Committee, by delivering
shares of Common Stock already owned by you and having a Fair Market Value on
the trading day immediately preceding the date of exercise equal to the exercise
price of the Option, or a combination of shares of Common Stock and cash, or
otherwise in accordance with the Plan.

         Kindly evidence your acceptance of the Option and your agreement to
comply with the provisions hereof and of the Plan by executing this letter under
the words "Agreed To and Accepted."

                                          Very truly yours,

                                          AMERICAN PACIFIC CORPORATION


                                          By:___________________________________
                                          Name:  John R. Gibson
                                          Title: Chairman, CEO and President

AGREED TO AND ACCEPTED:


__________________________________
[Optionee Name]

                              Exhibit 4.2 Page 2
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                                   Exhibit A
                                   ---------

American Pacific Corporation
3770 Howard Hughes Parkway, Suite 300
Las Vegas, Nevada 89109

Gentlemen:

         Notice is hereby given of my election to purchase _________ Shares of
Common Stock, $.10 par value per share (the "Shares"), of American Pacific
Corporation at a price of $4.87 per Share, pursuant to the provisions of the
option granted to me on April 24, 2001, under the Company's 2001 Stock Option
Plan. Enclosed in payment for the Shares is:

         my check in the amount of $________________.

     *   ___________ Shares having a total value of $_________________.

         The following information is supplied for use in issuing and
registering the Shares purchased hereby:

         Number of Certificates
         and Denominations              ______________________________

         Name                           ______________________________

         Address                        ______________________________

                                        ______________________________

         Social Security Number         ______________________________



Dated:   _______________, _______

                                             Very truly yours,


                                             ___________________________________
                                             Print Name:

*Subject to the approval of the Committee.

                              Exhibit 4.2 Page 3