1
                                                                       EXHIBIT 1

                       AMENDMENT NO. 2 TO RIGHTS AGREEMENT

                  Amendment No. 2 to the Rights Agreement, dated as of
August 30, 2000, by and between Sybron Chemicals Inc., a Delaware corporation
(the "Company"), and Fleet National Bank (formerly BankBoston, N.A.) (the
"Rights Agent").

                              W I T N E S S E T H :
                              - - - - - - - - - -

                  WHEREAS, on August 7, 1998 the Company and the Rights Agent
entered into a Rights Agreement (the "Original Agreement");

                  WHEREAS, on April 20, 1999, the Company and the Rights Agent
entered into Amendment No. 1 to the Original Agreement (the Original Agreement,
as amended by such amendment, is hereinafter referred to as the "Agreement" and
the terms of which are incorporated herein by reference and made a part hereof);

                  WHEREAS, the Company, with the unanimous approval of the Board
of Directors of the Company, has duly authorized the execution and delivery of
this Amendment No. 2 and this Amendment No. 2 is executed by the Company and the
Rights Agent pursuant to Section 26 of the Agreement.

                  NOW, THEREFORE, in consideration of the premises and mutual
agreements herein set forth, and intending to be legally bound hereby, the
parties hereto agree that the Agreement shall be and hereby is amended as
follows:

                  1. Defined Terms. Terms defined in the Agreement and used and
not otherwise defined herein shall have the meanings given to them in the
Agreement.

                  2. Amendment of Section 1. Section 1 of the Agreement is
amended to add the following at the end of the paragraph entitled "Acquiring
Person":

                  "Notwithstanding anything to the contrary contained in this
                  Agreement, neither Bayer Corporation, an Indiana corporation
                  ("Parent"), nor Project Toledo Acquisition Corp., a Delaware
                  corporation ("Purchaser"), shall at any time come within the
                  definition of an Acquiring Person as a result of the
                  transactions contemplated by the Agreement and Plan of Merger,
                  dated as of August 30, 2000, among Parent, Purchaser and the
                  Company (as such agreement may be amended from time to time,
                  the "Merger Agreement")."

                  3. Amendment of Section 3(a). Section 3(a) of the Agreement is
hereby amended to add the following paragraph at the end thereof:
   2

                           "Notwithstanding anything to the contrary contained
                  in this Agreement, the occurrence of (A) the approval,
                  execution and delivery of the Merger Agreement and the
                  Stockholder Agreement by and among Parent, Purchaser and
                  certain stockholders of the Company (as such agreement may be
                  amended from time to time, the "Stockholder Agreement"), (B)
                  the consummation of the transactions contemplated by the
                  Merger Agreement or the Stockholder Agreement or (C) the
                  announcement of any of the foregoing events will not,
                  individually or collectively, cause (i) the Rights to become
                  exercisable or (ii) the occurrence of a Distribution Date, a
                  Triggering Event or a Stock Acquisition Date."

                  4. Amendment of Section 7. Section 7 of the Agreement is
hereby amended to add the following at the end thereof:

                           "(g) Notwithstanding anything to the contrary
                  contained in this Agreement, immediately prior to the
                  acceptance for payment of shares of Common Stock pursuant to
                  the Offer (as defined in the Merger Agreement), all Rights
                  granted by this Agreement shall become null and void, this
                  Agreement shall be terminated and all provisions of this
                  Agreement, collectively and separately, shall be without
                  effect (including, without limitation, all sections pertaining
                  to redemption of the Rights)."

                  5. Rights Agreement as Amended. The term "Agreement" as used
in the Agreement shall be deemed to refer to the Agreement as amended hereby and
this Amendment No. 2 shall be effective as of August 30, 2000, as if executed on
such date. It is expressly understood and agreed that except as provided above,
all terms, conditions and provisions contained in the Agreement shall remain in
full force and effect without any further change or modification whatsoever.

                  6. Miscellaneous. This Amendment No. 2 shall for all purposes
be governed by and construed in accordance with the laws of the
State of Delaware.

                     [Remainder of Page Intentionally Blank]



                                       -6-

   3

                  IN WITNESS WHEREOF, the parties have caused this Amendment No.
2 to be duly executed and their respective corporate seals to be hereunto
affixed and attested, all as of the day and year first above written.

Attest:                                            SYBRON CHEMICALS INC.


By: /s/ John H. Schroeder                          By: /s/ Richard M. Klein
    ---------------------                              --------------------
    Name: John H. Schroeder                            Name: Richard M. Klein
    Title: Executive Vice President                    Title: President

Attest:                                            FLEET NATIONAL BANK


By: /s/  Sandra Burgess                            By: /s/ Margaret Prentice
    -------------------                                ---------------------
    Name: Sandra Burgess                               Name: Margaret Prentice
    Title: Account Manager                             Title: Managing Director


                                       -7-