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                                                                     EXHIBIT 4.6

                                SIPEX CORPORATION

                      NON-QUALIFIED STOCK OPTION AGREEMENT


         SIPEX Corporation, a Massachusetts corporation (the "Company"), hereby
grants as of the ___ day of __________ 1999, {{FIRSTNAME}} {{LASTNAME}} (the
"Employee"), an option to purchase a maximum OF {{SHARESGRANTED}} shares (the
"Option Shares") of its Common Stock, $.01 par value ("Common Stock"), at the
price of {{OPTIONPRICE}} per share, on the following terms and conditions:

      1. GRANT AS A NON-QUALIFIED STOCK OPTION. This option is a non-statutory
stock option and is not intended to qualify as an incentive stock option under
Section 422 of the Internal Revenue Code of 1986, as amended, and the
regulations thereunder (the "CODE").

      2. VESTING OF OPTION IF EMPLOYMENT CONTINUES. The Employee may exercise
this option for the number of shares of Common Stock set forth on the vesting
schedule set forth below if the Employee has continued to be employed by the
Company or any present or future parent or subsidiary of the Company
(collectively, "RELATED CORPORATIONS") in accordance with such vesting schedule.
Notwithstanding the foregoing, the Board may, in its discretion, accelerate the
date that any installment of this option becomes exercisable. The foregoing
rights are cumulative and (subject to Sections 3 or 4 hereof if the Employee
ceases to be employed by the Company) may be exercised only before the date
which is ten years from the date of this option grant.

         Less than one year from                  -      0 shares
                  the date hereof

         One year but less than                   -      an additional
                  two years from the date hereof        {{SHARES1}}shares

         Two years but less than                  -      an additional
                  three years from the date hereof      {{SHARES2}}shares

         Three years but less than                -      an additional
                  four years from the date hereof       {{SHARES3}}shares

         Four years or more                       -      an additional
                  from the date hereof                  {{SHARES4}}shares

         Five years or more                       -      an additional
                  from the date hereof                  {{SHARES5}}SHARES
                                                         ----------------

                                   TOTAL SHARES         {{SHARESGRANTED}} SHARES


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         3. TERMINATION OF EMPLOYMENT.

              (a) TERMINATION OTHER THAN FOR CAUSE: If the Employee ceases to be
employed by the Company and all Related Corporations, other than by reason of
death or disability as defined in Section 4 or termination for Cause as defined
in Section 3(c), no further installments of this option shall become
exercisable, and this option shall terminate (and may no longer be exercised)
after the passage of three months from the Employee's last day of employment,
but in no event later than the scheduled expiration date. In such a case, the
Employee's only rights hereunder shall be those which are properly exercised
before the termination of this option.

              (b) TERMINATION FOR CAUSE: If the employment of the Employee is
terminated for Cause (as defined in Section 3(c)), this option shall terminate
upon the Employee's receipt of written notice of such termination and shall
thereafter not be exercisable to any extent whatsoever.

              (c) DEFINITION OF CAUSE: "Cause" shall mean conduct involving one
or more of the following: (i) the substantial and continuing failure of the
Employee, after notice thereof, to render services to the Company or Related
Corporation in accordance with the terms or requirements of his or her
employment; (ii) disloyalty, gross negligence, willful misconduct, dishonesty or
breach of fiduciary duty to the Company or Related Corporation; (iii) the
commission of an act of embezzlement or fraud; (iv) deliberate disregard of the
rules or policies of the Company or Related Corporation which results in direct
or indirect loss, damage or injury to the Company or Related Corporation; (v)
the unauthorized disclosure of any trade secret or confidential information of
the Company or Related Corporation; or (vi) the commission of an act which
constitutes unfair competition with the Company or Related Corporation or which
induces any customer or supplier to breach a contract with the Company or
Related Corporation.

         4. DEATH; DISABILITY.

              (a) DEATH: If the Employee dies while in the employ of the Company
or any Related Corporation, this option may be exercised, to the extent
otherwise exercisable on the date of his or her death, by the Employee's estate,
personal representative or beneficiary to whom this option has been assigned
pursuant to Section 9, at any time within 180 days after the date of death, but
not later than the scheduled expiration date.

              (b) DISABILITY: If the Employee ceases to be employed by the
Company and all Related Corporations by reason of his or her disability, this
option may be exercised, to the extent otherwise exercisable on the date of the
termination of his or her employment, at any time within 180 days after such
termination, but not later than the scheduled expiration date.

              (c) EFFECT OF TERMINATION: At the expiration of the 180-day period
provided in paragraph (a) or (b) of this Section 4 or the scheduled expiration
date, whichever is the earlier, this option shall terminate (and shall no longer
be exercisable) and the only rights hereunder shall be those as to which the
option was properly exercised before such termination.


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      5. PARTIAL EXERCISE. This option may be exercised in part at any time and
from time to time within the above limits, except that this option may not be
exercised for a fraction of a share.

      6. PAYMENT OF PRICE. (a) The option price shall be paid in the following
manner:

                  (i)   in cash or by check;

                 (ii)   subject to paragraph 6(b) below, by delivery of shares
                        of the Company's Common Stock having a fair market value
                        equal as of the date of exercise to the option price;

                (iii)   by delivery of an assignment satisfactory in form and
                        substance to the Company of a sufficient amount of the
                        proceeds from the sale of the Option Shares and an
                        instruction to the broker or selling agent to pay that
                        amount to the Company; or

                 (iv)   by any combination of the foregoing.

              In the case of (ii) above, fair market value as of the date of
exercise shall be determined as of the last business day for which such prices
or quotes are available prior to the date of exercise and shall mean (i) the
average (on that date) of the high and low prices of the Common Stock on the
principal national securities exchange on which the Common Stock is traded, if
the Common Stock is then traded on a national securities exchange; or (ii) the
last reported sale price (on that date) of the Common Stock on the Nasdaq
National Market, if the Common Stock is not then traded on a national securities
exchange; or (iii) the closing bid price (or average of bid prices) last quoted
(on that date) by an established quotation service for over-the-counter
securities, if the Common Stock is not reported on the Nasdaq National Market.
If the Common Stock is not publicly traded at the time of exercise, "fair market
value" shall mean the fair value of the Common Stock as determined by the Board
after taking into consideration all factors which it deems appropriate,
including, without limitation, recent sale and offer prices of the Common Stock
in private transactions negotiated at arm's length.

              (b) LIMITATIONS ON PAYMENT BY DELIVERY OF COMMON STOCK: If the
Employee delivers Common Stock held by the Employee ("Old Stock") to the Company
in full or partial payment of the option price, and the Old Stock so delivered
is subject to restrictions or limitations imposed by agreement between the
Employee and the Company, an equivalent number of Option Shares shall be subject
to all restrictions and limitations applicable to the Old Stock to the extent
that the Employee paid for the Option Shares by delivery of Old Stock, in
addition to any restrictions or limitations imposed by this Agreement.
Notwithstanding the foregoing, the Employee may not pay any part of the exercise
price hereof by transferring Common Stock to the Company unless such Common
Stock has been owned by the Employee free of any substantial risk of forfeiture
for at least six months.

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      7. METHOD OF EXERCISING OPTION. Subject to the terms and conditions of
this Agreement, this option may be exercised by written notice to the Company at
its principal executive office, or to such transfer agent as the Company shall
designate. Such notice shall state the election to exercise this option and the
number of Option Shares for which it is being exercised and shall be signed by
the person or persons so exercising this option. Such notice shall be
accompanied by payment of the full purchase price of such shares, and the
Company shall deliver a certificate or certificates representing such shares as
soon as practicable after the notice shall be received. Such certificate or
certificates shall be registered in the name of the person or persons so
exercising this option (or, if this option shall be exercised by the Employee
and if the Employee shall so request in the notice exercising this option, shall
be registered in the name of the Employee and another person jointly, with right
of survivorship). In the event this option shall be exercised, pursuant to
Section 4 hereof, by any person or persons other than the Employee, such notice
shall be accompanied by appropriate proof of the right of such person or persons
to exercise this option.

         8. SECURITIES LAWS RESTRICTIONS ON RESALE. Until registered under the
Securities Act of 1933, as amended, or any successor statute (the "Securities
Act"), the Option Shares will be of an illiquid nature and will be deemed to be
"restricted securities" for purposes of the Securities Act. Accordingly, such
shares must be sold in compliance with the registration requirements of the
Securities Act or an exemption therefrom. Unless the Option Shares have been
registered under the Securities Act, each certificate evidencing any of the
Option Shares shall bear a legend substantially as follows:

         "The shares represented by this certificate are subject to restrictions
         on transfer and may not be sold, exchanged, transferred, pledged,
         hypothecated or otherwise disposed of except in accordance with and
         subject to all the terms and conditions of a certain Stock Option
         Agreement dated as of ___________ __, ____, a copy of which the Company
         will furnish to the holder of this certificate upon request and without
         charge."

      9. OPTION NOT TRANSFERABLE. This option is not transferable or assignable
except by will or by the laws of descent and distribution. During the Employee's
lifetime only the Employee can exercise this option.

      10. NO OBLIGATION TO EXERCISE OPTION. The grant and acceptance of this
option imposes no obligation on the Employee to exercise it.

      11. ADJUSTMENTS. In the event of any stock split, stock dividend,
extraordinary cash dividend, recapitalization, reorganization, merger,
consolidation, combination, exchange of shares, liquidation, spin-off, split-up,
or other similar change in capitalization or event, the number and class of
securities, vesting schedule and exercise price per share of this option shall
be adjusted by the Company (or a substituted option may be granted) to the
extent the Board shall determine, in good faith, that such an adjustment (or
substitution) is appropriate.

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      12. POOLING-OF-INTERESTS-ACCOUNTING. If the Company proposes to engage in
an acquisition intended to be accounted for as a pooling-of-interests, and in
the event that the provisions of this option, or any actions of the Board taken
in connection with such acquisition, are determined by the Company's or the
acquiring company's independent public accountants to cause such acquisition to
fail to be accounted for as a pooling-of-interests, then such provisions or
actions shall be amended or rescinded by the Board, without the consent of the
Employee, to be consistent with pooling-of-interests accounting treatment for
such acquisition if, and to the extent that, such recision would result in such
acquisition being accounted for on a pooling-of-interests basis.

      13. NO OBLIGATION TO CONTINUE EMPLOYMENT. Neither this Agreement nor the
grant of this option imposes any obligation on the Company or any Related
Corporation to continue the Employee in employment.

      14. NO RIGHTS AS STOCKHOLDER UNTIL EXERCISE. The Employee shall have no
rights as a stockholder with respect to the Option Shares until such time as the
Employee has exercised this option by delivering a notice of exercise and has
paid in full the purchase price for the shares so exercised in accordance with
Section 7. Except as is expressly provided herein with respect to certain
changes in the capitalization of the Company, no adjustment shall be made for
dividends or similar rights for which the record date is prior to such date of
exercise.

      15. WITHHOLDING TAXES. If the Company or any Related Corporation in its
discretion determines that it is obligated to withhold any tax in connection
with the exercise of this option, or in connection with the transfer of, or the
lapse of restrictions on, any Common Stock or other property acquired pursuant
to this option, the Employee hereby agrees that the Company or any Related
Corporation may withhold from the Employee's wages or other remuneration the
appropriate amount of tax. At the discretion of the Company or Related
Corporation, the amount required to be withheld may be withheld in cash from
such wages or other remuneration or in kind from the Common Stock or other
property otherwise deliverable to the Employee on exercise of this option. The
Employee further agrees that, if the Company or any Related Corporation does not
withhold an amount from the Employee's wages or other remuneration sufficient to
satisfy the withholding obligation of the Company or Related Corporation, the
Employee will make reimbursement on demand, in cash, for the amount
underwithheld.

      16. ARBITRATION. Any dispute, controversy, or claim arising out of, in
connection with, or relating to the performance of this Agreement or its
termination shall be settled by arbitration in the Commonwealth of
Massachusetts, pursuant to the rules then obtaining of the American Arbitration
Association. Any award shall be final, binding and conclusive upon the parties
and a judgment rendered thereon may be entered in any court having jurisdiction
thereof.

      17. PROVISION OF DOCUMENTATION TO EMPLOYEE. By signing this Agreement the
Employee acknowledges receipt of a copy of this Agreement.

      18. MISCELLANEOUS.

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              (a) NOTICES: All notices hereunder shall be in writing and shall
be deemed given when sent by certified or registered mail, postage prepaid,
return receipt requested, to the address set forth below. The addresses for such
notices may be changed from time to time by written notice given in the manner
provided for herein.

              (b) ENTIRE AGREEMENT; MODIFICATION: This Agreement constitutes the
entire agreement between the parties relative to the subject matter hereof, and
supersedes all proposals, written or oral, and all other communications between
the parties relating to the subject matter of this Agreement. This Agreement may
be modified, amended or rescinded only by a written agreement executed by both
parties.

              (c) SEVERABILITY: The invalidity, illegality or unenforceability
of any provision of this Agreement shall in no way affect the validity, legality
or enforceability of any other provision.

              (d) FRACTIONAL SHARES. If this option becomes exercisable for a
fraction of a share because of the adjustment provisions contained herein, such
fraction shall be rounded down.

              (e) DISSOLUTION OR LIQUIDATION. In the event of the proposed
dissolution or liquidation of the Company, then the Board shall, as to
outstanding options, at its discretion provide, upon written notice to the
Optionee (i) that all options must be exercised, to the extent then exercisable,
within a specified number of days of the date of such notice, at the end of
which period, the options shall terminate or (ii) that such options (including
those which have not yet vested) shall be exercisable within a specified number
of days of such notice, at the end of which period the options shall terminate.

              (f) ISSUANCES OF SECURITIES; CHANGES IN CAPITAL STRUCTURE. Except
as expressly provided herein, no issuance by the Company of shares of stock of
any class, or securities convertible into shares of stock of any class, shall
affect, and no adjustment by reason thereof shall be made with respect to, the
number or price of shares subject to this option. No adjustments need be made
for dividends paid in cash or in property other than securities of the Company.
If there shall be any change in the Common Stock of the Company through merger,
consolidation, reorganization, recapitalization, stock dividend, stock split,
combination or exchange of shares, spin-off, split-up or other similar change in
capitalization or event, the restrictions contained in this Agreement shall
apply with equal force to additional and/or substitute securities, if any,
received by the Optionee in exchange for, or by virtue of his or her ownership
of, Option Shares, except as otherwise determined by the Board.

              (g) SUCCESSORS AND ASSIGNS: This Agreement shall be binding upon
and inure to the benefit of the parties hereto and their respective successors
and assigns, subject to the limitations set forth in Section 9 hereof.

              (h) GOVERNING LAW: This Agreement shall be governed by and
interpreted in accordance with the laws of the Commonwealth of Massachusetts,
without giving effect to the principles of the conflicts of laws thereof.

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      IN WITNESS WHEREOF, the Company and the Employee have caused this
instrument to be executed as of the date first above written.



                                        SIPEX Corporation
____________________________            22 Linnell Circle
Employee                                Billerica, Massachusetts 01821

{{FIRSTNAME}} {{LASTNAME}}              By: _______________________________
{{ADDR1}}                                   James E. Donegan, Chairman, CEO
{{CITY}}, {{STATE}}  {{ZIPCODE}}