Exhibit 10.27




                                                     June 28, 2000


Mr. John F. McPeak
395 Kings Highway
Mickleton, NJ  08056

Dear John:

         Supplementing  the  terms  of your  Employment  Agreement  with  Sybron
Chemicals Inc. (the "Company"), this will confirm that, in the event there shall
be a Change in Control (as  hereinafter  defined) and, within six months of such
change in control your employment with the Company  terminates Without Cause (as
hereinafter defined), you shall be entitled, in lieu of any other severance pay,
to a lump  sum  payment,  payable  within  30 days of the date  your  employment
terminates, equal to the sum of the following:

         (i) any  severance  amounts you would be entitled to receive  under the
Company's  Severance Policy in effect immediately prior to the Change in Control
date (the "Severance Policy"); and

         (ii)     four (4) times your monthly base salary in effect on the
Change in Control date.

         Provided,  however, that in no event shall the severance payable to you
hereunder  be less than twelve (12) times your  monthly base salary in effect on
the Change in Control date.

         Termination  of your  employment  with the Company  Without Cause shall
mean termination under  circumstances such that you would be entitled to receive
severance payments under the Severance Policy.

         A  "Change  of  Control"  shall be  deemed  to have  occurred  upon the
earliest  to  occur  of the  following  events:  (a)  the  sale or  disposal  of
substantially  all of the  assets of the  Company,  or (b) 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 15%,
shall have become the beneficial owner of, or shall have obtained voting control
over,  more  than  fifty  percent  (50%) of the  outstanding  shares  of (i) the
Company's  Common Stock, or (ii) the Common Stock of the Company  resulting from
the merger or consolidation of the Company with or into any other entity.

         If the above correctly reflects our  understanding,  please so indicate
by signing in the space provided below for such purpose.

                                          Sincerely,



                                          Richard M. Klein
                                          President and Chief Executive Officer

AGREED:

/s/ John F. McPeak
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John F. McPeak