1
As filed with the Securities and Exchange Commission on May 24, 2001.

                                                   Registration No. 333-________


                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC. 20549

                                    FORM S-8

                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

                                SIPEX Corporation
             (Exact name of registrant as specified in its charter)

                Massachusetts                            04-6135748
       (State or other jurisdiction of                (I.R.S. Employer
       incorporation or organization)               Identification No.)

                                22 Linnell Circle
                               Billerica, MA 01821
                                 (978) 667-8700
               (Address of Principal Executive Offices) (Zip Code)
                          -----------------------------

                      2000 Non-Qualified Stock Option Plan
                            (Full title of the plan)

                          -----------------------------

                                James E. Donegan
                             Chief Executive Officer
                                SIPEX Corporation
                                22 Linnell Circle
                               Billerica, MA 01821
                                 (978) 667-8700
           (Name and address including zip code and telephone number,
                   including area code, of agent for service)

                          -----------------------------

                                   Copies to:

                             Kenneth J. Gordon, Esq.
                         TESTA, HURWITZ & THIBEAULT, LLP
                                 125 High Street
                           Boston, Massachusetts 02110
                                 (617) 248-7000
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                         CALCULATION OF REGISTRATION FEE




                                                                     Proposed
                                                                      maximum         Proposed maximum
           Title of securities                Amount to be           offering            aggregate                Amount of
             to be registered                 registered(1)       price per share      offering price         registration fee
                                                                                                  
2000 NON-QUALIFIED STOCK OPTION PLAN
Common Stock, par value $.01 per share           494,770             $12.688(2)      $ 6,277,641.76(2)          $1,569.41(2)
                                                  55,000             $ 6.870(2)      $   377,850.00(2)          $   94.46
                                                 450,230             $12.99 (3)        5,848,487.70(3)          $1,462.12(3)

NON-PLAN OPTIONS
Common Stock, par value                          710,000             $12.688(2)      $ 9,008,480.00(2)          $2,252.12(2)
$.01 per share                                    55,000             $ 6.870(2)      $   377,850.00(2)          $   94.46
                                               ---------                             --------------             ---------
TOTAL                                          1,765,000                             $21,890,309.46             $5,472.57



(1)        Plus such additional shares as may be required pursuant to the plan
           in the event of a stock dividend, split-up of shares,
           recapitalization or other similar change in the Common Stock.

(2)        Such shares are issuable upon exercise of outstanding options with
           fixed exercise prices. Pursuant to Rule 457(h)(1) of Regulation C,
           the aggregate offering price and the fee have been computed upon the
           basis of the price at which the options may be exercised. The
           offering price per share set forth for such shares is the exercise
           price per share at which such options are exercisable.

(3)        Pursuant to Rule 457(c) and (h)(1) of Regulation C of the Securities
           Act, the price of $12.99 per share, is the average of the high and
           low prices of the Common Stock as reported on The Nasdaq National
           Market on May 22, 2001 and is set forth solely for purposes of
           calculating the filing fee for those shares without a fixed exercise
           price.
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           This Registration Statement registers additional securities of the
same class as other securities for which (i) Registration Statement No.
333-06123 on Form S-8 as filed with the Securities and Exchange Commission on
June 17, 1996 (relating to the Registrant's 1988 Non-Statutory Stock Option
Plan, 1991 Non-Statutory Stock Option Plan, 1993 Stock Option and Incentive
Plan, 1994 Stock Option and Incentive Plan, 1996 Incentive Stock Option Plan,
1996 Non-Employee Director Stock Option Plan and 1996 Employee Stock Purchase
Plan) is effective, (ii) Registration Statement No. 333-32329 on Form S-8 as
filed with the Securities and Exchange Commission on July 29, 1997 relating to
the Registrant's 1997 Stock Option Plan is effective, and (iii) Registration
Statement No. 333-31410 on Form S-8 as filed with the Securities and Exchange
Commission on March 1, 2000 relating to the Registrant's 1999 Stock Option Plan
is effective. Pursuant to General Instruction E to Form S-8, the contents of the
above-listed Registration Statements are hereby incorporated by reference.

                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

ITEM 1.    PLAN INFORMATION.

           The documents containing the information specified in this Item 1
will be sent or given to employees, directors or others as specified by Rule
428(b)(1). In accordance with the rules and regulations of the Securities and
Exchange Commission (the "Commission") and the instructions to Form S-8, such
documents are not being filed with the Commission either as part of this
Registration Statement or as prospectuses or prospectus supplements pursuant to
Rule 424.

ITEM 2.    REGISTRANT INFORMATION AND EMPLOYEE PLAN ANNUAL INFORMATION.

           The documents containing the information specified in this Item 2
will be sent or given to employees as specified by Rule 428(b)(1). In accordance
with the rules and regulations of the Commission and the instructions to Form
S-8, such documents are not being filed with the Commission either as part of
the Registration Statement or as prospectuses or prospectus supplements pursuant
to Rule 424.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.    INCORPORATION OF DOCUMENTS BY REFERENCE.

           The following documents filed by SIPEX Corporation (the "Registrant")
with the Commission pursuant to the Securities Exchange Act of 1934, as amended
(the "Exchange Act"), are incorporated in this Registration Statement by
reference as of their respective dates:

           (a)        The Registrant's Annual Report on Form 10-K for the fiscal
                      year ended December 31, 2000, filed with the Commission on
                      March 23, 2001;

           (b)        The Registrant's Quarterly Report on From 10-Q for the
                      quarter ended March 31, 2001;

           (c)        The section entitled "Description of Registrant's
                      Securities to be Registered" contained in the Registrant's
                      registration statement on Form 8-A filed with the
                      Commission on March 1, 1996 pursuant to Section 12(g) of
                      the Exchange Act and incorporating by reference the
                      information contained in the Registrant's Registration
                      Statement on Form S-1 (SEC File No. 333-14639) initially
                      filed with the Commission on March 1, 1996.

           All documents subsequently filed with the Commission by the
Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act,
prior to the filing of a post-effective amendment which indicates that all
securities offered herein have been sold or which deregisters all securities
then remaining unsold, shall be deemed to be incorporated by reference in this
Registration Statement and to be a part hereof from the date of filing of such
documents.
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ITEM 4. DESCRIPTION OF SECURITIES.

Not applicable.

ITEM 5. INTEREST OF NAMED EXPERTS AND COUNSEL

Not applicable.

ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

           Massachusetts General Laws Chapter 156B, Section 67 provides that a
corporation may indemnify its directors and officers to the extent specified in
or authorized by (i) the articles of organization, (ii) a by-law adopted by the
shareholders, or (iii) a vote adopted by the holders of a majority of the shares
of stock entitled to vote on the election of directors. In all instances, the
extent to which a corporation provides indemnification to its directors and
officers under Section 67 is optional. Massachusetts General Laws Chapter 156B,
Section 67 forbids the indemnification of any person with respect to any matter
to which he shall have been adjudicated in any proceeding not to have acted in
good faith in the reasonable belief that his action was in the best interest of
the corporation.

           The Company's Restated By-Laws indemnifies the directors and officers
against liabilities arising out of legal proceedings brought against them by
reason of their status as directors and officers or by reason of their agreeing
to serve, at the request of the Company, as a director or officer of another
organization. Under the Restated By-Laws, each director and officer shall be
indemnified by the Company for all costs and expenses (including attorneys'
fees), judgments, liabilities and amounts paid in settlement of such
proceedings, even if he is not successful on the merits, if he acted in good
faith in the reasonable belief that his action was in the best interest of the
Company. The Board of Directors may authorize advancing litigation expenses to a
director or officer at his request upon receipt of an undertaking by such
director or officer to repay such expenses if it is ultimately determined that
he is not entitled to indemnification for such expense. The Restated By-Laws
provide that the directors and officers of the Company shall be indemnified by
the Company to the fullest extent authorized by Massachusetts Law, as it now
exists or may in the future be amended. In addition, the Restated Articles
provide that the directors of the Company will not be personally liable for
monetary damages to the Company for breaches of their fiduciary duty as
directors, unless they violated their duty of loyalty to the Company or its
shareholders, acted in bad faith, knowingly or intentionally violated the law,
authorized illegal dividends or redemptions or derived an improper personal
benefit from their action as directors.

           The Company has entered into separate indemnification agreements with
each of its directors and executive officers, whereby the Company agreed, among
other things, (i) to indemnify them to the fullest extent permitted by the
Business Corporation Law of the Commonwealth of Massachusetts, subject to
specified limitations, against certain liabilities actually and reasonably
incurred by them in any proceedings in which they are a party that may arise by
reason of their status as directors, officers, employees or agents or may arise
by reason of their serving as such at the request of the Company for another
entity and (ii) to advance their expenses incurred as a result of any proceeding
against them as to which they could be indemnified. The Company intends to enter
into similar separate indemnification agreements with any directors or officers
who may join the Company in the future.

ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED.

Not applicable.
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ITEM 8.  EXHIBITS.



 Exhibit No.                      Description of Exhibit
            
       4.1*    Restated Articles of Organization of the Registrant (filed as
               Exhibit 3.2 to the Registrant's Registration Statement on Form
               S-1, File No. 333-1328, and incorporated herein by reference).

       4.2*    Restated By-Laws of the Registrant (filed as Exhibit 3.3 to the
               Registrant's Registration Statement on Form S-1, File No.
               333-1328, and incorporated herein by reference).

       4.3     SIPEX Corporation 2000 Non-Qualified Stock Option Plan.

       4.4     Form of Non-Qualified Stock Option Agreement (Plan).

       4.5     Form of Non-Qualified Stock Option Agreement (Non-Plan).

       4.6     Non-Qualified Stock Option Agreement dated January 16, 2001 by
               and between the Registrant and Bruce Diamond.

       5.1     Opinion of Testa, Hurwitz & Thibeault, LLP.

      23.1     Consent of Testa, Hurwitz & Thibeault, LLP (contained in its
               opinion as Exhibit 5.1).

      23.2     Consent of KPMG, LLP.

      23.3     Consent of Sallmann, Yang & Alameda.

      24.1     Power of Attorney (included as part of the signature page of this
               Registration Statement).


*Incorporated by reference to Exhibits to the Registrant's Registration
Statement on Form S-1, No. 333-1328


ITEM 9.    UNDERTAKINGS.

           (a)        The undersigned Registrant hereby undertakes:

                      (1)        To file, during any period in which offers or
                                 sales are being made, a post-effective
                                 amendment to this Registration Statement:

                                 (i)        To include any prospectus required
                                            by Section 10(a)(3) of the
                                            Securities Act of 1933;

                                 (ii)       To reflect in the prospectus any
                                            facts or events arising after the
                                            effective date of the Registration
                                            Statement (or the most recent
                                            post-effective amendment thereof)
                                            which, individually or in the
                                            aggregate, represent a fundamental
                                            change in the information set forth
                                            in the Registration Statement; and
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                                 (iii)      To include any material information
                                            with respect to the plan of
                                            distribution not previously
                                            disclosed in the Registration
                                            Statement or any material change to
                                            such information in the Registration
                                            Statement;

                                 provided, however, that paragraphs (a)(1)(i)
                                 and (a)(1)(ii) do not apply if the information
                                 required to be included in a post-effective
                                 amendment by those paragraphs is contained in
                                 periodic reports filed with or furnished to the
                                 Commission by the Registrant pursuant to
                                 Section 13 or Section 15(d) of the Securities
                                 Exchange Act of 1934 that are incorporated by
                                 reference in the Registration Statement.

                      (2)        That, for the purpose of determining any
                                 liability under the Securities Act of 1933,
                                 each such post-effective amendment shall be
                                 deemed to be a new registration statement
                                 relating to the securities offered therein, and
                                 the offering of such securities at that time
                                 shall be deemed to be the initial bona fide
                                 offering thereof.

                      (3)        To remove from registration by means of a
                                 post-effective amendment any of the securities
                                 being registered which remain unsold at the
                                 termination of the offering.

           (b)        The undersigned Registrant hereby undertakes that, for
                      purposes of determining any liability under the Securities
                      Act of 1933, each filing of the Registrant's annual report
                      pursuant to Section 13(a) or Section 15(d) of the
                      Securities Exchange Act of 1934 (and, where applicable,
                      each filing of any employee benefit plan's annual report
                      pursuant to Section 15(d) of the Securities Exchange Act
                      of 1934) that is incorporated by reference in the
                      Registration Statement shall be deemed to be a new
                      registration statement relating to the securities offered
                      therein, and the offering of such securities at that time
                      shall be deemed to be the initial bona fide offering
                      thereof.

           (c)        Insofar as indemnification for liabilities arising under
                      the Securities Act of 1933 may be permitted to directors,
                      officers and controlling persons of the Registrant
                      pursuant to the foregoing provisions, or otherwise, the
                      Registrant has been advised that in the opinion of the
                      Securities and Exchange Commission such indemnification is
                      against public policy as expressed in the Act and is,
                      therefore, unenforceable. In the event that a claim for
                      indemnification against such liabilities (other than the
                      payment by the Registrant of expenses incurred or paid by
                      a director, officer or controlling person of the
                      Registrant in the successful defense of any action, suit
                      or proceeding) is asserted by such director, officer or
                      controlling person in connection with the securities being
                      registered, the Registrant will, unless in the opinion of
                      its counsel the matter has been settled by controlling
                      precedent, submit to a court of appropriate jurisdiction
                      the question whether such indemnification by it is against
                      public policy as expressed in the Act and will be governed
                      by the final adjudication of such issue.
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                                   SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Billerica, the Commonwealth of Massachusetts, on this
24th day of May, 2001.

                                      SIPEX CORPORATION

                                      By:   /s/  James E. Donegan
                                           ------------------------------------
                                           James E. Donegan
                                           Chairman of the Board of Directors
                                           and Chief Executive Officer

                                POWER OF ATTORNEY

           EACH SUCH PERSON WHOSE SIGNATURE appears below constitutes and
appoints, jointly and severally, James E. Donegan and Frank R. DiPietro and each
of them, with full power to act without the other, his true and lawful
attorney-in-fact and agent, with the power of substitution and resubstitution,
for him and in his name, place and stead, in any and all capacities, to sign any
amendments to this Registration Statement on Form S-8 (including post-effective
amendments) and to file the same, with all exhibits thereto, and other documents
in connection therewith, with the Securities and Exchange Commission, hereby
ratifying and confirming all that said attorney-in-fact, or his or her
substitute or substitutes, may do or cause to be done by virtue hereof.

           Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the date indicated.



                  SIGNATURE                                        TITLE                                         DATE
                                                                                                       
  /s/  James E. Donegan                         Chairman of the Board of Directors, Chief                    May 24, 2001
  --------------------------------------        Executive Officer and Director
  James E. Donegan

  /s/  Frank R. DiPietro                        Executive Vice President, Finance, Chief                     May 24, 2001
  --------------------------------------        Financial Officer, Treasurer (principal
  Frank R. DiPietro                             financial officer and accounting officer)
                                                and Clerk

  /s/  Manfred Loeb                             Director                                                     May 24, 2001
  --------------------------------------
  Manfred Loeb

  /s/  Lionel H. Olmer                          Director                                                     May 24, 2001
  --------------------------------------
  Lionel H. Olmer

  /s/  John L. Sprague                          Director                                                     May 24, 2001
  --------------------------------------
  John L. Sprague

  /s/  Doug McBunnie                            Director                                                     May 24, 2001
  --------------------------------------
  Doug McBurnie

  /s/  Willy Sansen                             Director                                                     May 24, 2001
  --------------------------------------
  Willy Sansen

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        Exhibit                     Description of Exhibit
                 
          4.1*      Restated Articles of Organization of the Registrant.

          4.2*      Restated By-Laws of the Registrant.

          4.3       SIPEX Corporation 2000 Non-Qualified Stock Option
                    Plan.

          4.4       Form of Non-Qualified Stock Option Agreement (Plan).

          4.5       Form of Non-Qualified Stock Option Agreement
                    (Non-Plan).

          4.6       Non-Qualified Stock Option Agreement dated January 16,
                    2001 by and between the Registrant and Bruce Diamond.

          5.1       Opinion of Testa, Hurwitz & Thibeault, LLP.

          23.1      Consent of Testa, Hurwitz & Thibeault, LLP (contained
                    in its opinion as Exhibit 5.1).

          23.2      Consent of  KPMG, LLP.

          23.3      Consent of Sallmann, Yang & Alameda.

          24.1      Power of Attorney (included as part of the signature
                    page of this Registration Statement).


*Incorporated by reference to Exhibits to the Registrant's Registration
Statement on Form S-1, No. 333-1328