Exhibit 10.31


                              SYBRON CHEMICALS INC.

                            SHARE PARTICIPATION PLAN

                                 AMENDMENT NO. 2

                  Sybron Chemicals Inc., a Delaware corporation (hereinafter
called the "Company") established, effective June 11, 1990, the "Sybron Chemical
Industries Inc. Share Participation Plan", renamed the "Sybron Chemicals Inc.
Share Participation Plan" (hereinafter the "Plan").  On October 30, 1992, the
Plan was first amended through the adoption of Amendment No. 1.

                  The Committee desires to further amend the Plan as hereinafter
set forth.

                NOW, THEREFORE,  subject to the  approval  of the Board of
Directors of the Company, the Plan is hereby amended as follows:

                  1.       Paragraph 1, subparagraph (d) of the Plan is hereby
amended to read in its entirety as follows:

                  "(d)     "Committee" shall mean a committee comprised of R.M.
Klein, S.F. Ladin, J.H. Schroeder and S.R. Adler, or such other persons as shall
be appointed by the Board of Directors of SCI to serve in addition to, or in
lieu of, the aforementioned appointees."

                  2.       Paragraph 1, subparagraph (e)(i) of the Plan is
hereby amended to read in its entirety as follows:

                           "(i) have completed at least one full year of service
                  with the Company or are at the Executive Grade level; provided
                  that,  after  April 1,  2000,  the  Committee  shall  have the
                  discretion to waive such one-year  requirement with respect to
                  any Employee". 3. Paragraph 1, subparagraph (h) of the Plan is
                  hereby amended to read in its entirety as follows:

                           "(h) "Triggering Event" shall mean:

                                     (i) the sale or disposal of substantially
all of the assets of the Company, or

                                    (ii) the date any entity, person or group,
within the meaning of Section 13(d)(3) or Section 14(d)(2) of the Securities
Exchange Act of 1934, as amended, other than the Company or Citigroup or any of
their  subsidiaries,  any employee benefit plan (or related trust) sponsored or
maintained by the Company or any of its subsidiaries,  or any other person or
group in which the present  management of the Company  shall have an  aggregate
equity  interest,  on a fully  diluted basis, of no less than 20%, shall have
become the beneficial  owner of, or shall have  obtained  voting  control  over,
more  than  fifty  percent  (50%) of the outstanding shares of (A) the Company's
Common Stock, or (B) the Common Stock of the Company  resulting from the merger
or  consolidation  of the Company with or into any other entity."

                  4.       Paragraph 3(d) of the Plan is hereby amended to read
in its entirety as follows:
                           "(d) If an Awardee is an Optionee in the Sybron
                  Chemicals Inc. 1992 Stock Option Plan (the "Stock Option
                  Plan") as defined therein, the Stock Option Plan   Committee
                  may   designate  a  number  or  percent  of Participation
                  Shares  awarded  to the  Awardee  which will be canceled prior
                  to a Triggering  Event in conjunction  with the exercise  of a
                  Stock  Option  which  has been  granted  to the Awardee
                  pursuant  to the  Stock  Option  Plan.  The terms and
                  conditions  under  which  such  Participation  Shares  will be
                  canceled  shall  be  set  forth  in  the  Stock  Option  Grant
                  Agreement (the  "Agreement")  made between the Awardee and the
                  Company.  The  Agreement  may  apply to  Participation  Shares
                  awarded  to the  Awardee  before  or  after  the  date  of the
                  Agreement  but prior to the  exercise  of all or a part of the
                  Non-qualified  Stock Option.  Any such  cancellation  shall be
                  duly noted in the registry.  Notwithstanding the foregoing, in
                  no event shall  Participation  Shares  awarded  from and after
                  April 1, 2000 be canceled as a result of the exercise of Stock
                  Options  granted  pursuant  to  the  Stock  Option  Plan."  5.
                  Paragraphs  4(a), 4(b) and 5 of the Plan are hereby amended by
                  replacing all references to the "first anniversary of the
                  Triggering Event" with the "sixth monthly anniversary of the
                  Triggering Event".

                  6.       The Plan in all other respects is hereby ratified and
                  confirmed.

                  IN WITNESS WHEREOF, Sybron Chemicals Inc. has caused this
amendment to the Plan to be signed, effective  April 1, 2000 and its  corporate
seal to be hereunto  affixed by its duly authorized officers this 17th day of
April, 2000.

                                                     Sybron Chemicals Inc.
                                                     By: /s/ Steven F. Ladin

ATTEST:
By:
        (Corporate Seal)