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                                                                    EXHIBIT 4.1
                                                                
                                                                 EXECUTION COPY
                                                                 -------------- 

                                FIRST AMENDMENT
                                       TO
                     AMENDED AND RESTATED CREDIT AGREEMENT


          FIRST AMENDMENT, dated as of July 9, 1996 (this "Amendment"), to the
Amended and Restated Credit Agreement, dated as of July 31, 1995 (the "Credit
Agreement"), among Sybron International Corporation, a Wisconsin corporation
(the "Parent"), Ormco Corporation, a Delaware corporation ("Ormco"), Kerr
Corporation, a Delaware corporation ("Kerr"), Nalge Company, a Delaware
corporation ("Nalge"), Erie Scientific Company, a Delaware corporation ("Erie"),
Barnstead Thermolyne Corporation, a Delaware corporation ("Barnstead"; Ormco,
Kerr, Nalge, Erie and Barnstead are collectively referred to herein as the
"Subsidiary Borrowers"), the several banks and other financial institutions from
time to time parties thereto (the "Lenders"), Chase Securities Inc. (formerly
known as Chemical Securities Inc.), as Arranger, and Chemical Bank, a New York
banking corporation, as administrative agent for the Lenders thereunder (in such
capacity, the "Administrative Agent").


                              W I T N E S S E T H:


          WHEREAS, pursuant to the Credit Agreement, the Lenders have agreed to
make, and have made, certain loans and other extensions of credit to the Parent
and the Subsidiary Borrowers; and

          WHEREAS, the Parent and the Subsidiary Borrowers have requested, and,
upon this Amendment becoming effective, the Lenders have agreed, that (i) the
Revolving Credit Commitments of the Lenders shall be increased by $50,000,000 in
the aggregate and (ii) certain provisions of the Credit Agreement be amended in
the manner provided for in this Amendment.

          NOW, THEREFORE, the parties hereto hereby agree as follows:

     I.   Defined Terms.  Terms defined in the Credit Agreement and used
herein shall have the meanings given to them in the Credit Agreement.

     II.  Amendments to Credit Agreement.

          1.  Amendments to Section 1.  Subsection 1.1 of the Credit Agreement
is hereby amended by deleting the definitions of "Aggregate Outstanding
Extensions of Credit", "Borrowing Date", "Business Day", "Loan", "Notes", and
"Type" contained therein in their entirety and adding the following definitions 
in alphabetical order:



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                "Aggregate Outstanding Extensions of Credit":  as to any Lender
           at any time, an amount equal to the sum of (a) the aggregate
           principal amount of all Revolving Credit Loans made by such Lender
           then outstanding, (b) such Lender's Revolving Credit Commitment
           Percentage of the L/C Obligations then outstanding, and (c) for all
           purposes other than the calculation of the commitment fees pursuant
           to subsection 2.9, such Lender's Revolving Credit Commitment
           Percentage of the aggregate principal amount of all (i) CAF Advances
           then outstanding and (ii) Swing Line Loans then outstanding.

                "Amendment Effective Date":  the date on which the First
           Amendment dated as of July 9, 1996 to the Credit Agreement became
           effective pursuant to the terms thereof.

                "Borrowing Date":  any Business Day specified in a notice
           pursuant to subsection 2.3, 2.5(a), 2.13 or 3.2 as a date on which
           the Parent either on behalf of itself or any of the Subsidiary
           Borrowers requests (a) the Lenders to make Loans or CAF Advances, as
           the case may be, hereunder and/or (b) the Issuing Bank to issue a
           Letter of Credit hereunder.

                "Business Day":  a day other than a Saturday, Sunday or other
           day on which commercial banks in New York City are authorized or
           required by law to close; provided, that when such term is used to
           describe a day on which a borrowing, payment or interest rate
           determination is to be made in respect of a Eurodollar Rate CAF
           Advance, such day shall also be a day on which dealings in foreign
           currencies and exchange between banks may be carried on in London,
           England.

                "CAF Advance":  each CAF Advance made pursuant to subsection
           2.4.

                "CAF Advance Availability Period":  the period from and
           including the Amendment Effective Date to and including the date
           which is 7 days prior to the Termination Date.

                "CAF Advance Confirmation":  each confirmation by the Parent,
           on behalf of itself or any other Revolving Credit Borrower, of its
           acceptance of CAF Advance Offers, which confirmation shall be
           substantially in the form of Exhibit J and shall be delivered to the
           Administrative Agent by facsimile transmission.

                "CAF Advance Interest Payment Date":  as to each CAF Advance,
           each interest payment date specified for such CAF Advance in the
           related CAF Advance Request.

                "CAF Advance Maturity Date":  as to any CAF Advance, the date
           specified by the Parent, on behalf of itself or any other Revolving
           Credit Borrower, as the case may be,


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           pursuant to paragraph 2.5(d)(ii) in its acceptance of the related
           CAF Advance Offer.

                "CAF Advance Note":  as defined in subsection 2.7, which term
           shall include any QFL CAF Advance Note issued pursuant to subsection
           11.7.

                "CAF Advance Offer":  each offer by a Lender to make CAF
           Advances pursuant to a CAF Advance Request, which offer shall
           contain the information specified in Exhibit K and shall be
           delivered to the Administrative Agent by telephone, immediately
           confirmed by facsimile transmission.

                "CAF Advance Request":  each request by the Parent, on behalf
           of itself or any other Revolving Credit Borrower, for Lenders to
           submit bids to make CAF Advances, which request shall contain the
           information in respect of such requested CAF Advances specified in
           Exhibit L and shall be delivered to the Administrative Agent in
           writing, by facsimile transmission, or by telephone, immediately
           confirmed by facsimile transmission.

                "Eurodollar Rate CAF Advance":  any CAF Advance made pursuant
           to a Eurodollar Rate CAF Advance Request.

                "Eurodollar Rate CAF Advance Request":  any CAF Advance Request
           requesting the Lenders to offer to make CAF Advances at an interest
           rate equal to the Eurodollar Rate plus (or minus) a margin.

                "Fixed Rate CAF Advance":  any CAF Advance made pursuant to a
           Fixed Rate CAF Advance Request.

                "Fixed Rate CAF Advance Request":  any CAF Advance Request
           requesting the Lenders to offer to make CAF Advances at a fixed rate
           (as opposed to a rate composed of the Eurodollar Rate plus (or
           minus) a margin).

                "Loan":  any loan (including any CAF Advance) made by any
           Lender pursuant to this Agreement.

                "Notes":  the collective reference to the Revolving Credit
           Notes, the CAF Advance Notes, the Swing Line Notes and the Term
           Notes.

                "QFL CAF Advance Note":  as defined in subsection 11.7.

                "Type":  as to certain Loans made hereunder, its nature as an
           ABR Loan or a Eurodollar Loan.

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                      2.   Amendments to Section 2. (a)  Section 2 is
     hereby amended as follows:

                (i) by deleting the first sentence of subsection 2.1(a) thereof
           in its entirety and substituting in lieu thereof the following:

                           "Subject to the terms and conditions
                      hereof, each Lender severally agrees to make
                      revolving credit loans ("Revolving Credit
                      Loans") to the Revolving Credit Borrowers
                      from time to time during the Revolving Credit
                      Commitment Period in an aggregate principal
                      amount at any one time outstanding to all
                      Revolving Credit Borrowers, when added to
                      such Lender's Revolving Credit Commitment
                      Percentage of (i) the then outstanding L/C
                      Obligations, (ii) the aggregate principal
                      amount of all Swing Line Loans then
                      outstanding and (iii) the aggregate principal
                      amount of all CAF Advances then outstanding,
                      not to exceed the amount of such Lender's
                      Revolving Credit Commitment, provided that
                      nothing contained herein shall be deemed to
                      prohibit the making of, or relieve any Lender
                      of its obligation to make, Revolving Credit
                      Loans the proceeds of which are to be applied
                      solely to the repayment of principal of
                      Refunded Swing Line Loans pursuant to
                      subsection 2.16(c) except that in no event
                      shall any Lender be obligated to make
                      Revolving Credit Loans in excess of its
                      Revolving Credit Commitment";

                (ii) by adding the following subsections at the end of
           subsection 2.3:

                           "2.4.  CAF Advances.  Subject to the terms and
                      conditions of this Agreement, the Revolving Credit
                      Borrowers may borrow CAF Advances from time to time
                      on any Business Day during the CAF Advance
                      Availability Period.  CAF Advances may be borrowed
                      in amounts such that the aggregate amount of (i)
                      Revolving Credit Loans, (ii) L/C Obligations, (iii)
                      Swing Line Loans and (iv) CAF Advances outstanding
                      at any time shall not exceed the aggregate amount of
                      the Revolving Credit Commitments at such time. 
                      Within the limits and on the conditions hereinafter
                      set forth with respect to CAF Advances, the
                      Revolving Credit Borrowers from time to time may
                      borrow, repay and reborrow CAF Advances.

                           2.5  Procedure for CAF Advance Borrowing.   (a) The
                      Parent, on behalf of itself or any other Revolving Credit
                      Borrower, shall request CAF Advances by




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                      delivering a CAF Advance Request to the Administrative
                      Agent, not later than 12:00 Noon (New York City time)
                      four Business Days prior to the proposed Borrowing Date
                      (in the case of a Eurodollar Rate CAF Advance Request),
                      and not later than 10:00 A.M. (New York City time) one
                      Business Day prior to the proposed Borrowing Date (in the
                      case of a Fixed Rate CAF Advance Request).  Each CAF
                      Advance Request in respect of any Borrowing Date may
                      solicit bids for CAF Advances on such Borrowing Date in
                      an aggregate principal amount of $10,000,000 or an
                      integral multiple of $1,000,000 in excess thereof and
                      having not more than three alternative CAF Advance
                      Maturity Dates.  The CAF Advance Maturity Date for each
                      CAF Advance shall be the date set forth therefor in the
                      relevant CAF Advance Request, which date shall be (i) not
                      less than 7 days nor more than 180 days after the
                      Borrowing Date therefor, in the case of a Fixed Rate CAF
                      Advance, (ii) one, two, three or six months after the
                      Borrowing Date therefor, in the case of a Eurodollar CAF
                      Advance and (iii) not later than the Termination Date, in
                      the case of any CAF Advance.  The Administrative Agent
                      shall notify each Lender promptly by facsimile
                      transmission of the contents of each CAF Advance Request
                      received by the Administrative Agent.

                     (b)  In the case of a Eurodollar Rate CAF Advance Request,
           upon receipt of notice from the Administrative Agent of the contents
           of such CAF Advance Request, each Lender may elect, in its sole
           discretion, to offer irrevocably to make one or more CAF Advances at
           the applicable Eurodollar Rate plus (or minus) a margin determined by
           such Lender in its sole discretion for each such CAF Advance. Any
           such irrevocable offer shall be made by delivering a CAF Advance
           Offer to the Administrative Agent, before 10:30 A.M. (New York City
           time) on the day that is three Business Days before the proposed
           Borrowing Date, setting forth:

                           (i) the maximum amount of CAF Advances for each CAF
                      Advance Maturity Date and the aggregate maximum amount of
                      CAF Advances for all CAF Advance Maturity Dates which
                      such Lender would be willing to make (which amounts may,
                      subject to subsection 2.4, exceed such Lender's Revolving
                      Credit Commitment); and

                           (ii) the margin above or below the appropriate
                      Eurodollar Rate at which such Lender is willing to make
                      each such CAF Advance.

           The Administrative Agent shall advise the Parent, on behalf of
           itself or the relevant Revolving Credit Borrower, as the case may
           be, before 11:00 A.M. (New York City time) on the date which is
           three Business Days before the proposed Borrowing Date of the
           contents of each such CAF Advance




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           Offer received by it.  If the Administrative Agent, in its capacity
           as a Lender, shall elect, in its sole discretion, to make any such
           CAF Advance Offer, it shall advise the Revolving Credit Borrower of
           the contents of its CAF Advance Offer before 10:15 A.M. (New York
           City time) on the date which is three Business Days before the
           proposed Borrowing Date.

                In the case of a Fixed Rate CAF Advance Request, upon receipt
           of notice from the Administrative Agent of the contents of such CAF
           Advance Request, each Lender may elect, in its sole discretion, to
           offer irrevocably to make one or more CAF Advances at a rate of
           interest determined by such Lender in its sole discretion for each
           such CAF Advance.  Any such irrevocable offer shall be made by
           delivering a CAF Advance Offer to the Administrative Agent before
           9:30 A.M. (New York City time) on the proposed Borrowing Date,
           setting forth:

                           (i) the maximum amount of CAF Advances for each CAF
                      Advance Maturity Date, and the aggregate maximum amount
                      for all CAF Advance Maturity Dates, which such Lender
                      would be willing to make (which amounts may, subject to
                      subsection 2.4, exceed such Lender's Revolving Credit
                      Commitment); and

                           (ii) the rate of interest at which such Lender is
                      willing to make each such CAF Advance.

           The Administrative Agent shall advise the Parent, on behalf of
           itself or the relevant Revolving Credit Borrower, as the case may
           be, before 10:00 A.M. (New York City time) on the proposed Borrowing
           Date of the contents of each such CAF Advance Offer received by it.
           If the Administrative Agent, in its capacity as a Lender, shall
           elect, in its sole discretion, to make any such CAF Advance Offer,
           it shall advise such Revolving Credit Borrower of the contents of
           its CAF Advance Offer before 9:15 A.M. (New York City time) on the
           proposed Borrowing Date.

           (d)  Before 11:30 A.M. (New York City time) three Business Days
           before the proposed Borrowing Date (in the case of CAF Advances
           requested by a Eurodollar Rate CAF Advance Request) and before 10:30
           A.M. (New York City time) on the proposed Borrowing Date (in the
           case of CAF Advances requested by a Fixed Rate CAF Advance Request),
           the Parent, on behalf of itself or the relevant Revolving Credit
           Borrower, as the case may be, in its absolute discretion, shall:

                           (i) cancel such CAF Advance Request by giving the
                      Administrative Agent telephone notice to that effect, or





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          (ii) by giving telephone notice to the Administrative Agent
     (immediately confirmed by delivery to the Administrative Agent of a CAF
     Advance Confirmation by facsimile transmission) (A) subject to the
     provisions of subsection 2.5(e), accept one or more of the offers made by
     any Lender or Lenders pursuant to subsection 2.5(b) or subsection 2.5(c),
     as the case may be, and (B) reject any remaining offers made by Lenders
     pursuant to subsection 2.5(b) or subsection 2.5(c), as the case may be.

     (e)  The Parent's acceptance of CAF Advances in response to any CAF Advance
Offers shall be subject to the following limitations:

          (i) the amount of CAF Advances accepted for each CAF Advance Maturity
     Date specified by any Lender in its CAF Advance Offer shall not exceed the
     maximum amount for such CAF Advance Maturity Date specified in such CAF
     Advance Offer;

          (ii) the aggregate amount of CAF Advances accepted for all CAF Advance
     Maturity Dates specified by any Lender in its CAF Advance Offer shall not
     exceed the aggregate maximum amount specified in such CAF Advance Offer for
     all such CAF Advance Maturity Dates;

          (iii) the Parent may not accept offers for CAF Advances for any CAF
     Advance Maturity Date in an aggregate principal amount in excess of the
     maximum principal amount requested in the related CAF Advance Request; and

          (iv) if the Parent accepts any of such offers, it must accept offers
     based solely upon pricing for each relevant CAF Advance Maturity Date and
     upon no other criteria whatsoever, and if two or more Lenders submit offers
     for any CAF Advance Maturity Date with identical pricing and the Parent
     accepts any of such offers but does not wish to (or, by reason of the
     limitations set forth in subsection 2.4, cannot) borrow the total amount
     offered by such Lenders with such identical pricing, the Parent shall
     accept offers from all of such Lenders in amounts allocated among them pro
     rata according to the amounts offered by such Lenders (with appropriate
     rounding, in the sole discretion of the Parent, to assure that each
     accepted CAF Advance is an integral multiple of $1,000,000); provided that
     if the number of Lenders that submit offers for any CAF Advance Maturity
     Date at identical pricing is such that, after the Parent accepts such
     offers pro rata in accordance with the foregoing provisions of this
     paragraph, the CAF Advance to be made by any such Lender would be less than
     $5,000,000 principal amount,




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                      the number of such Lenders shall be reduced by the
                      Administrative Agent by lot until the CAF Advances to be
                      made by each such remaining Lender would be in a
                      principal amount of $5,000,000 or an integral multiple of
                      $1,000,000 in excess thereof.

                  (f) If the Parent notifies the Administrative Agent that
          a CAF Advance Request is cancelled pursuant to subsection 2.5(d)(i),
          the Administrative Agent shall give prompt telephone or fax notice
          thereof to the Lenders.

                  (g) If the Parent accepts pursuant to subsection 
          2.5(d)(ii) one or more of the offers made by any Lender or
          Lenders, the Administrative Agent promptly shall notify each Lender
          which has made such an offer of  the aggregate amount of such CAF
          Advances to be made on such Borrowing Date for each CAF Advance
          Maturity Date and  the acceptance or rejection of any offers to make
          such CAF Advances made by such Lender.  Before 12:00 Noon (New York
          City time) on the Borrowing Date specified in the applicable CAF
          Advance Request, each Lender whose CAF Advance Offer has been
          accepted shall make available to the Administrative Agent at its
          office set forth in subsection 11.2 the amount of CAF Advances to be
          made by such Lender, in immediately available funds.  The
          Administrative Agent will make such funds available to the relevant
          Revolving Credit Borrower as soon as practicable on such date at such
          office of the Administrative Agent.  As soon as practicable after
          each Borrowing Date, the Administrative Agent shall notify each
          Lender of the aggregate amount of CAF Advances advanced on such
          Borrowing Date and the respective CAF Advance Maturity Dates thereof.

                  2.6 CAF Advance Payments. (a)  The Revolving Credit Borrower
          in respect of each CAF Advance shall pay to the Administrative
          Agent, for the account of the Lender which has made such CAF Advance,
          on the applicable CAF Advance Maturity Date the then unpaid principal
          amount of such CAF Advance.  The Revolving Credit Borrowers shall not
          have the right to prepay any principal amount of any CAF Advance
          without the consent of the Lender to which such CAF Advance is owed.

                  (b)  The Revolving Credit Borrower in respect of each CAF
           Advance shall pay interest on the unpaid principal amount of such
           CAF Advance made to such Revolving Credit Borrower from the
           Borrowing Date to the applicable CAF Advance Maturity Date at the
           rate of interest specified in the CAF Advance Offer accepted by the
           Revolving Credit Borrower in connection with such CAF Advance
           (calculated on the basis of a 360-day year for actual days elapsed),
           payable on each applicable CAF Advance Interest Payment Date.





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               (c)  If any principal of, or interest on, any CAF Advance shall
           not be paid when due (whether at the stated maturity, by acceleration
           or otherwise), such CAF Advance shall, without limiting any rights of
           any Lender under this Agreement, bear interest from the date on which
           such payment was due at a rate per annum which is 2% above the rate
           which would otherwise be applicable to such CAF Advance until the
           stated CAF Advance Maturity Date of such CAF Advance, and for each
           day thereafter at a rate per annum which is 2% above the ABR, in each
           case until paid in full (as well after as before judgment). Interest
           accruing pursuant to this paragraph (c) shall be payable from time to
           time on demand.

               2.7  CAF Advance Notes. The CAF Advances made by each Lender 
          shall be evidenced by a promissory note of the Revolving Credit
          Borrowers, substantially in the form of Exhibit M-1 with appropriate
          insertions (a "CAF Advance Note"), payable to the order of such
          Lender and representing the obligation of each Revolving Credit
          Borrower to pay the lesser of (a) the amount of the Aggregate
          Revolving Credit Commitment and (b) the unpaid principal amount of
          all CAF Advances made by such Lender to such Revolving Credit
          Borrower, with interest on the unpaid principal amount from time to
          time outstanding of each CAF Advance evidenced thereby as prescribed
          in subsection 2.6(b).  Each Lender is hereby authorized to record,
          with respect to the appropriate Revolving Credit Borrower, the date
          and amount of each CAF Advance made by such Lender, the CAF Advance
          Maturity Date thereof, the date and amount of each payment of
          principal thereof and the interest rate with respect thereto on the
          schedule attached to and constituting part of its CAF Advance Note,
          and any such recordation shall constitute prima facie evidence of the
          accuracy of the information so recorded; provided, however, that the
          failure to make any such recordation shall not affect the obligations
          of the Revolving Credit Borrowers hereunder or under any CAF Advance
          Note. Each CAF Advance Note shall be dated the Amendment Effective
          Date, and each CAF Advance evidenced thereby shall bear interest for
          the period from and including the Borrowing Date of such CAF Advance
          on the unpaid principal amount thereof from time to time outstanding
          at the applicable rate per annum determined as provided in, and such
          interest shall be payable as specified in, subsection 2.6(b).

                2.8  Certain Restrictions.  A CAF Advance Request may request
           offers for CAF Advances to be made on not more than one Borrowing
           Date and to mature on not more than three CAF Advance Maturity
           Dates.  No CAF Advance Request may be submitted earlier than five
           Business Days after submission of any other CAF Advance Request.";





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               (iii) by deleting the first sentence of subsection 2.5 thereof
(as such subsection is identified in the Credit Agreement prior to this
Amendment) in its entirety and substituting in lieu thereof the following:

                "The Parent shall have the right, upon not less than five
           Business Days' notice from the Parent to the Administrative Agent,
           to terminate the Aggregate Revolving Credit Commitment or, from time
           to time, to reduce the amount of the Aggregate Revolving Credit
           Commitment; provided that no such termination or reduction shall be
           permitted if, after giving effect thereto and to any prepayments of
           the Revolving Credit Loans, the Swing Line Loans and the CAF
           Advances (to the extent permitted by subsection 2.6) made on the
           effective date thereof, the aggregate principal amount of the
           Revolving Credit Loans, the Swing Line Loans and the CAF Advances
           then outstanding, when added to the then outstanding L/C
           Obligations, would exceed the Aggregate Revolving Credit Commitment
           then in effect.";

               (iv) by deleting the first sentence of subsection 2.9 thereof (as
such subsection is identified in the Credit Agreement prior to this Amendment)
in its entirety and substituting in lieu thereof the following:

                "Subject to the limitations contained in subsections 2.1 and
           2.6 in respect of prepayments of Revolving Credit Loans, each
           Borrower may on the last day of any Interest Period with respect
           thereto, in the case of Eurodollar Loans, or at any time and from
           time to time, in the case of ABR Loans, prepay the Loans made to
           such Borrower, in whole or in part, without premium or penalty, upon
           at least four Business Days' irrevocable notice in the case of
           Eurodollar Loans, and upon at least one Business Days' irrevocable
           notice in the case of ABR Loans, from the Parent to the
           Administrative Agent, or upon irrevocable notice received by the
           Administrative Agent prior to 11:00 A.M. on the requested prepayment
           date in the case of Swing Line Loans, specifying the Borrower making
           the prepayment, the date and amount of prepayment, whether the
           prepayment is of Term Loans, Swing Line Loans, Revolving Credit
           Loans or a combination thereof, and, if a combination thereof, the
           amount allocable to each and whether the prepayment is of Eurodollar
           Loans, ABR Loans or a combination thereof, and, if of a combination
           thereof, the amount allocable to each."

               (v) by deleting subsection 2.10(d) thereof (as such subsection is
identified in the Credit Agreement prior to this Amendment) in its entirety and
substituting in lieu thereof the following:

             "(d)  Each prepayment of the Loans pursuant to this subsection
2.15 shall be accompanied by payment in full of




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           all accrued interest thereon to and including the date of such
           prepayment, together with any additional amounts owing pursuant to
           subsection 2.26.  Each reduction of the Aggregate Revolving Credit
           Commitment pursuant to this subsection 2.15 shall be accompanied by
           a prepayment of the Revolving Credit Loans, the Swing Line Loans and
           the CAF Advances (if permitted by subsection 2.6) then outstanding
           in an amount equal to the excess, if any, of the sum of (i) the
           Revolving Credit Loans, (ii) the Swing Line Loans, (iii) the CAF
           Advances and (iv) the L/C Obligations then outstanding, over the
           Aggregate Revolving Credit Commitment, as so reduced.  Any
           prepayment required by the immediately preceding sentence shall be
           applied first to the outstanding Swing Line Loans until they are
           paid in full, second to the Revolving Credit Loans and third to the
           CAF Advances (if permitted by subsection 2.6).  To the extent that
           in connection with the requirements hereof the Revolving Credit
           Loans, the Swing Line Loans and the CAF Advances have been reduced
           to zero and the L/C Obligations then outstanding exceed the
           Aggregate Revolving Credit Commitment, as so reduced, the Parent
           shall, simultaneously with such reduction, deposit in a cash
           collateral account with the Administrative Agent having terms and
           conditions reasonably acceptable to the Administrative Agent, an
           amount equal to the sum of (i) the amount by which such outstanding
           L/C Obligations exceed the Aggregate Revolving Credit Commitment, as
           reduced and (ii) an amount equal to the commissions, fees and
           estimated expenses (in each case as determined pursuant to
           subsection 3.3) expected to be incurred by the Parent with respect
           to such L/C Obligations over a one year period."; and

               (vi) by deleting the first two sentences of subsection 2.17(a)
(as such subsection is identified in the Credit Agreement prior to this
Amendment) in their entirety and substituting in lieu thereof the following:

                "Each borrowing by any Borrower from the Lenders hereunder
           (other than any borrowing of Swing Line Loans or CAF Advances), each
           payment by any Borrower on account of any commitment fee hereunder
           (except as otherwise specifically provided herein) and any reduction
           of the Commitments of the Lenders shall be made pro rata according
           to the respective relevant Commitment Percentages of the Lenders.
           Each payment (including each prepayment) by any Borrower on account
           of principal of and interest on the Loans made to such Borrower
           shall be made pro rata according to the respective principal or
           interest, as the case may be, in respect of such Loans then due and
           owing to the Lenders."

               3.  Amendments to Section 4.    (a)  Section 4 of the Credit 
Agreement is hereby amended by deleting subsection 4.16 thereof in its
entirety and substituting in lieu thereof the following:




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          "4.16  Purpose of Loans.  (i)  The proceeds of the Term Loans shall be
     used to finance the Nunc Acquisition and to refinance indebtedness
     outstanding under the Prior Credit Agreement and to pay fees and other
     expenses related thereto and (ii) the proceeds of the Revolving Credit
     Loans, the Swing Line Loans and the CAF Advances shall be used to finance
     the Nunc Acquisition, to refinance indebtedness outstanding under the
     Prior Credit Agreement and to finance the working capital needs of the
     Parent and its Subsidiaries and for general corporate purposes, including
     acquisitions other than the Nunc Acquisition, provided that no more than
     $180,000,000 of the proceeds of the Loans may be used to finance the Nunc
     Acquisition."
        
          4.  Amendments to Section 6.  (a)  Section 6 of the Credit Agreement
is hereby amended as follows:

          (i) by deleting subsection 6.2(d) thereof in its entirety and
     substituting in lieu thereof the following:
     
                     "(d) concurrently with the delivery of the financial
          statements referred to in subsections 6.1(a) and 6.1(b), a
          certificate of a Responsible Officer of the Parent indicating the
          Parent's Interest Coverage Ratio and Leverage Ratio for such period
          of four fiscal quarters of    the Parent;"
     
          (ii) by adding the following new paragraph at the end of
     subsection 6.2(d):
     
                     "(e)  concurrently with the delivery of the
          financial statements referred to in subsection 6.1(a), a certificate
          of the independent certified public accountants reporting on such
          financial statements stating that in making the examination necessary
          therefor no knowledge was obtained of any Default or Event of Default
          relating to the covenants contained in subsections 7.1, 7.2, 7.4, 7.7
          and 7.9, except as specified in such certificate; and"; and
     
          (iii) by relettering subsection 6.2(e) as subsection 6.2(f).
     
          5.  Amendments to Section 7.  (a) Section 7 is hereby amended as 
follows:

          (i) by deleting subsection 7.7 thereof in its entirety and
     inserting in lieu thereof the following:

           "7.7  Limitation on Leases.  Permit Consolidated Lease Expense
     for any fiscal year of the Parent and its Subsidiaries to exceed   
     $10,000,000."






   13

                                                                              13



          (ii) by deleting subsection 7.9 thereof in its entirety and inserting
     in lieu thereof the following:

               7.9  Limitation on Capital Expenditures.  Make or
     commit to make any Capital Expenditure (other than in connection with any
     acquisition of a business unit specifically permitted by subsection
     7.10(e)) except for expenditures in the ordinary course of business not
     exceeding, in the aggregate for the Parent and its Subsidiaries during any
     of the periods set forth below, the amount set forth opposite such period:

          Period                                        Amount

     10/1/95 - 9/30/96                                $38,000,000
     10/1/96 - 9/30/97                                $36,000,000
     10/1/97 - 9/30/98                                $38,000,000
     10/1/98 - 9/30/99                                $38,000,000
     10/1/99 - 9/30/00                                $40,000,000
     10/1/00 - 9/30/01                                $40,000,000
     10/1/01 - Termination Date                       $40,000,000

          6.  Amendments to Section 11.  (a)  Section 11 of the Credit 
Agreement is hereby amended as follows:

          (i)  by deleting subsection 11.6(e) thereof in its entirety and
     substituting in lieu thereof the following:

               "(e) Upon its receipt of an Assignment and Acceptance executed 
     by an assigning Lender and an Assignee (and, in the case of an Assignee
     that is not then a Lender or an Affiliate thereof, by the Administrative
     Agent) together with payment to the Administrative Agent by the assigning
     Lender or such Assignee of a registration and processing fee of $4,000 (or
     $1,000 in the case of an Assignee that is already a Lender), the
     Administrative Agent shall (i) promptly accept such Assignment and
     Acceptance and (ii) on the effective date determined pursuant thereto
     record the information contained therein in the Register and give notice
     of such acceptance and recordation to the Lenders and the Parent. On or
     prior to such effective date, each of the Borrowers, at its own expense,
     shall execute and deliver to the Administrative Agent (in exchange for the
     Revolving Credit Note, CAF Advance Note or Term Note of the assigning
     Lender) a new Revolving Credit Note, CAF Advance Note or Term Note, as the
     case may be, to the order of such Assignee in amounts reflecting the
     Revolving Credit Commitment or Term Loan, as the case may be, assumed by
     it pursuant to such Assignment and Acceptance and, if the assigning Lender
     has retained a Revolving Credit Commitment
        



   14

                                                                              14


          or Term Loan hereunder, a new Revolving Credit Note, CAF Advance Note
          or Term Note, as the case may be, to the order of the assigning
          Lender in amounts reflecting the Revolving Credit Commitment or Term
          Loan, as the case may be, retained by it hereunder. Such new Notes
          shall be dated the Closing Date in the case of Revolving Credit Notes
          and Term Notes, and the Amendment Effective Date in the case of CAF
          Advance Notes, and shall otherwise be in the form of the Note
          replaced thereby";
        
          (ii)  by deleting subsections 11.7(a) and (b) thereof in their
     entirety and substituting in lieu thereof the following:

                "11.7  QFL Notes.  (a)  Any Lender that is not a "bank" within
          the meaning of Section 881(c)(3)(A) of the Code and that satisfies
          the requirements of subsection 2.25(b) (a "Qualified Foreign Lender")
          shall, upon receipt of the written request of the Parent or the
          Administrative Agent, and may upon its own written request to the
          Administrative Agent (i) receive, or exchange any Revolving Credit
          Note held by or assigned to it for, a QFL Revolving Credit Note
          substantially in the form attached hereto as Exhibit A-2 (a "QFL
          Revolving Credit Note"), (ii) receive, or exchange any Term Note held
          by or assigned to it for, a QFL Term Note substantially in the form
          attached hereto as Exhibit B-2 (a "QFL Term Note") and (iii) receive,
          or exchange any CAF Advance Note held by or assigned to it for, a QFL
          CAF Advance Note substantially in the form attached hereto as M-2 (a
          "QFL CAF Advance Note"); the QFL Revolving Credit Notes, the QFL Term
          Notes and the QFL CAF Advance Notes are collectively referred to
          herein as the "QFL Notes"). Any QFL Notes issued pursuant to this
          subsection 11.7 shall be (A) dated the Closing Date in the case of a
          QFL Revolving Credit Note or a QFL Term Note, or dated the Amendment
          Effective Date in the case of a QFL CAF Advance Note, (B) issued in
          the name of the relevant Lender and (C) issued (i) in the same
          principal amounts as such exchanged Revolving Credit Notes, Term
          Notes or CAF Advance Notes as the case may be, or (ii) in the case of
          a Lender not exchanging Revolving Credit Notes, Term Notes or CAF
          Advance Notes, in amounts reflecting such Lender's Revolving Credit
          Commitment or Term Loans, as the case may be.
        
                (b)  The Parent and each Subsidiary Borrower agree that, upon 
          the request of or delivery of a request to a Qualified Foreign Lender
          pursuant to paragraph (a) of this subsection 11.7, it shall execute
          and deliver QFL Notes to the Administrative Agent conforming to the
        



   15

                                                                              15


          requirements of such paragraph and pursuant to the terms thereof.  To
          the extent relevant, each Qualified Foreign Lender shall surrender
          its Notes to the Administrative Agent in connection with any exchange
          pursuant to this subsection 11.7.  If an exchange of a Revolving
          Credit Note, Term Note or CAF Advance Note is to occur, upon receipt
          by the Administrative Agent of the existing Revolving Credit Note,
          Term Note or CAF Advance Note to be exchanged for such QFL Notes in
          accordance with this paragraph, the Administrative Agent shall
          forward the QFL Notes to the Qualified Foreign Lender which
          surrendered its Revolving Credit Note, Term Note or CAF Advance Note
          for exchange and shall forward such exchanged Revolving Credit Note,
          Term Note or CAF Advance Note to the Parent marked "cancelled."  Once
          issued, QFL Notes (i) shall, subject to the terms of this Amendment,
          be deemed to and shall be "Term Notes", "Revolving Credit Notes" or
          "CAF Advance Notes", as the case may be, for all purposes under this
          Agreement, the Security Documents and the other Loan Documents, (ii)
          may not be exchanged for "Revolving Credit Notes", "Term Notes" or
          "CAF Advance Notes" notwithstanding anything to the contrary in this
          Agreement, and (iii) shall at all times thereafter be QFL Notes,
          including, without limitation, following any transfer or assignment
          thereof;"; and
        
          (iii) by deleting subsection 11.8(a) thereof in its entirety and 
     substituting in lieu thereof the following:

                "(a)  If any Lender (a "benefitted Lender") shall at any time 
          receive any payment of all or part of the Loans owing to it, or
          interest thereon, or receive any collateral in respect thereof
          (whether voluntarily or involuntarily, by set-off, pursuant to events
          or proceedings of the nature referred to in Section 8(f) or
          otherwise), in a greater proportion than any such payment to or
          collateral received by any other Lender, if any, in respect of such
          other Lender's Loans then due and owing, or interest thereon then due
          and owing, such benefitted Lender shall purchase for cash from such
          other Lender a participating interest in such portion of each such
          other Lender's Revolving Credit Loans, Term Loans or CAF Advances, as
          the case may be, or shall provide such other Lenders with the
          benefits of any such collateral, or the proceeds thereof, as shall be
          necessary to cause such benefitted Lender to share the excess payment
          or benefits of such collateral or proceeds ratably with each of the
          Lenders; provided, however, that if all or any portion of such excess
          payment or benefits is thereafter recovered from such benefitted
          Lender, such purchase shall be rescinded, and the purchase price and
          benefits returned, to the extent of such recovery, but without
          interest."
        



   16
                                                                              16


          7.  Amendments to Sections 1 through 11.  Sections 1 through 11 of 
the Credit Agreement are hereby amended by renumbering all references and
cross-references to subsections 2.4 through 2.22 contained in the Credit
Agreement prior to the Amendment Effective Date as subsections 2.9 through
2.27, respectively.

          8.  Amendment to Schedule I to the Credit Agreement.  Schedule I to 
the Credit Agreement is hereby amended by deleting Schedule I in its entirety 
and substituting in lieu thereof Exhibit A hereto.

          9.  Amendments to Exhibits to the Credit Agreement.  The Exhibits to
the Credit Agreement are hereby amended by inserting Exhibits B through F 
hereto as Exhibits J through M-2, respectively, to the Credit Agreement.

     III.  Conditions to Effectiveness.  This Amendment shall become effective
on the date (the "Amendment Effective Date") on which all of the following
conditions precedent have been satisfied or waived:
        
     1.  The Parent, the Subsidiary Borrowers, the Administrative Agent and the
Lenders (as required by the Credit Agreement) shall have executed and delivered
to the Administrative Agent this Amendment.

     2.  The Administrative Agent shall have received a copy of the 
resolutions, in form and substance satisfactory to the Administrative Agent, of
the Board of Directors of each of the Parent and the Subsidiary Borrowers
authorizing the execution, delivery and performance of this Amendment, certified
by the Secretary or an Assistant Secretary of such party as of the Amendment
Effective Date, which certificate shall state that the resolutions thereby
certified have not been amended, modified, revoked or rescinded as of the date
of such certificate.
        
     3.  The Administrative Agent shall have received, to the extent that it has
not theretofore received, a certificate of the Secretary or Assistant Secretary
of the Parent and the Subsidiary Borrowers, dated the Amendment Effective Date,
as to the incumbency and signature of each of the officers signing this
Amendment, and any other instrument or document delivered by such party in
connection herewith, together with evidence of the incumbency of such Secretary
or Assistant Secretary.

     4.  The Administrative Agent shall have received a written legal opinion of
counsel to the Parent and the Subsidiary Borrowers in form and substance
satisfactory to the Administrative Agent and its counsel.

     5.  The Administrative Agent and the Lenders shall have received all fees
due from the Parent.





   17

                                                                              17



     IV.  Purchase and Sale of Revolving Credit
          Commitments and Revolving Credit Loans.

          On the Amendment Effective Date, but immediately prior to any 
borrowing on such date under the Credit Agreement, without the necessity of
further action by any party, one or more Lenders (the "Selling Lenders") as
specified on Schedule 1 hereto shall sell, transfer and assign to one or more
other Lenders (the "Purchasing Lenders") as specified on Schedule 1 hereto a
portion of the Selling Lender's right, title and interest in and to its
Revolving Credit Commitments and/or Revolving Credit Loans as specified on
Schedule 1 hereto, without recourse, representation or warranty, and each
Purchasing Lender shall purchase, take and acquire from a Selling Lender a
portion of such Selling Lender's right, title and interest in and to its
Revolving Credit Commitments and/or Revolving Credit Loans as specified on
Schedule 1 hereto, so that after giving effect to all such transfers, each
Lender's interest in the Revolving Credit Commitments and Revolving Credit
Loans shall be as specified on Schedule 1 hereto.
        
     V.  General.

     1.  Representation and Warranties.  To induce the Administrative Agent and
the Lenders parties hereto to enter into this Amendment, the Parent and the
Subsidiary Borrowers hereby represent and warrant to the Administrative Agent
and all of the Lenders as of the Amendment Effective Date that the
representations and warranties made by the Parent and the Subsidiary Borrowers
in the Loan Documents are true and correct in all material respects on and as
of the Amendment Effective Date, before and after giving effect to the
effectiveness of this Amendment, as if made on and as of the Amendment
Effective Date.

     2.  Payment of Expenses.  The Parent and the Subsidiary Borrowers agree 
to pay or reimburse the Administrative Agent for all of its out-of-pocket costs
and reasonable expenses incurred in connection with this Amendment, any other
documents prepared in connection herewith and the transactions contemplated
hereby, including, without limitation, the reasonable fees and disbursements of
counsel to the Administrative Agent.
        
     3.  No Other Amendments; Confirmation.  Except as expressly amended, 
modified and supplemented hereby, the provisions of the Credit Agreement and
the Notes are and shall remain in full force and effect.
        
     4.  Governing Law; Counterparts.    This Amendment and the rights and
obligations of the parties hereto shall be governed by, and construed and
interpreted in accordance with, the laws of the State of New York.

     (b)  This Amendment may be executed by one or more of the parties to this
Agreement on any number of separate counterparts,




   18

                                                                              18


and all of said counterparts taken together shall be deemed to constitute one
and the same instrument.  This Amendment may be delivered by facsimile
transmission of the relevant signature pages hereof.

     IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
duly executed and delivered by their respective proper and duly authorized
officers as of the day and year first above written.

                                        SYBRON INTERNATIONAL CORPORATION
                                                                        
                                                                        
                                        By:  
                                           -----------------------------------
                                             Title:                     
                                                                        
                                                                        
                                        ORMCO CORPORATION               
                                                                        
                                                                        
                                        By:                             
                                           -----------------------------------
                                             Title:                     
                                                                        
                                                                        
                                        KERR CORPORATION                
                                                                        
                                                                        
                                        By:                             
                                           -----------------------------------
                                             Title:                     
                                                                        
                                                                        
                                        NALGE COMPANY                   
                                                                        
                                                                        
                                        By:                             
                                           -----------------------------------
                                             Title:                     
                                                                        
                                                                        
                                        ERIE SCIENTIFIC COMPANY         
                                                                        
                                                                        
                                        By:                             
                                           -----------------------------------
                                             Title:                     
                                                                        
                                                                        
                                        BARNSTEAD THERMOLYNE CORPORATION
                                                                        
                                                                        
                                        By:                             
                                           -----------------------------------
                                             Title:                     
                                                                        
                                                                        




   19

                                                                              19



                                        CHEMICAL BANK,                    
                                          as Administrative Agent and as a
                                          Lender                          
                                                                          
                                                                          
                                                                          
                                        By:
                                           ----------------------------------
                                             Title:                       
                                                                          
                                                                          
                                                                          
                                        ABN AMRO BANK N.V.                
                                                                          
                                                                          
                                                                          
                                        By:                               
                                           ----------------------------------
                                             Title:                       
                                                                          
                                                                          
                                                                          
                                        By:                               
                                           ----------------------------------
                                             Title:                       
                                                                          
                                                                          
                                                                          
                                        BANK OF AMERICA ILLINOIS          
                                                                          
                                                                          
                                                                          
                                        By:                               
                                           ----------------------------------
                                             Title:                       
                                                                          
                                                                          
                                                                          
                                        BANK OF MONTREAL                  
                                                                          
                                                                          
                                                                          
                                        By:                               
                                           ----------------------------------
                                             Title:                       
                                                                          
                                                                          
                                                                          
                                        BANK ONE, COLUMBUS, NA            
                                                                          
                                                                          
                                                                          
                                        By:                               
                                           ----------------------------------
                                             Title:                       
                                                                          




   20

                                                                              20



                                                THE BANK OF NOVA SCOTIA



                                                By:____________________________
                                                   Title:


                                                BANK OF SCOTLAND



                                                By:____________________________
                                                   Title:



                                                BANQUE FRANCAISE DU COMMERCE  
                                                  EXTERIEUR



                                                By:____________________________
                                                   Title:



                                                By:____________________________
                                                   Title:


                                                BANQUE PARIBAS



                                                By:____________________________
                                                   Title:



                                                By:____________________________
                                                   Title:




                                                CAISSE NATIONALE DE CREDIT
                                                AGRICOLE



                                                By:____________________________
                                                   Title:






   21
                                                                        21      





                                        COMERICA BANK                          
                                                                               
                                                                               
                                                                               
                                        By:    
                                             ----------------------------------
                                             Title:                            
                                                                               
                                                                               
                                                                               
                                        CREDIT LYONNAIS CAYMAN ISLAND          
                                          BRANCH                            
                                                                               
                                                                               
                                                                               
                                        By:                                    
                                             ----------------------------------
                                             Title:                            
                                                                               
                                                                               
                                                                               
                                        DG BANK, DEUTSCHE GENOSSENSCHAFTSBANK  
                                          CAYMAN ISLAND BRANCH              
                                                                               
                                                                               
                                                                               
                                        By:                                    
                                             ----------------------------------
                                             Title:                            
                                                                               
                                                                               
                                                                               
                                        By:                                    
                                             ----------------------------------
                                             Title:                            
                                                                               
                                                                               
                                                                               
                                        FIRST BANK NATIONAL ASSOCIATION        
                                                                               
                                                                               
                                                                               
                                        By:                                    
                                             ----------------------------------
                                             Title:                            
                                                                               
                                                                               
                                                                               
                                                                               
                                        FLEET BANK OF MASSACHUSETTS, N.A.      
                                                                               
                                                                               
                                                                               
                                        By:                                    
                                             ----------------------------------
                                             Title:                            
                                                                               
                                                                               
                                                                               
                                        



   22

                                                                             
                                                                        22



                                        THE FUJI BANK, LIMITED                
                                                                                
                                                                                
                                                                                
                                        By:                                     
                                             ------------------------------     
                                             Title:                             
                                                                                
                                                                                
                                                                                
                                        THE LONG-TERM CREDIT BANK OF JAPAN,     
                                          LTD. CHICAGO BRANCH                
                                                                                
                                                                                
                                                                                
                                        By:                                     
                                             ------------------------------     
                                             Title:                             
                                                                                
                                                                                
                                                                                
                                        MELLON BANK, N.A.                       
                                                                                
                                                                                
                                                                                
                                        By:                                     
                                             ------------------------------     
                                             Title:                             
                                                                                
                                                                                
                                                                                
                                        THE BANK OF TOKYO-MITSUBISHI, Ltd.,     
                                          CHICAGO BRANCH                     
                                                                                
                                                                                
                                                                                
                                        By:                                     
                                             ------------------------------     
                                             Title:                             
                                                                                
                                                                                
                                                                                
                                        THE MITSUBISHI TRUST AND BANKING        
                                          CORPORATION                           
                                                                                
                                                                                
                                        By:                                     
                                             ------------------------------     
                                             Title:                             
                                                                                
                                                                                
                                                                                
                                        NBD BANK                                
                                                                                
                                                                                
                                                                                
                                        By:                                     
                                             ------------------------------     
                                             Title:                             
                                                                                
                                                                                
                                                                              
                                                                              
                                                                              
                                                                              
                                                                              
   23

                                                                            23




                                        THE SAKURA BANK, LIMITED                
                                                                                
                                                                                
                                                                                
                                        By:                                     
                                             ------------------------------     
                                             Title:                             
                                                                                
                                                                                
                                                                                
                                        SOCIETE GENERALE                        
                                                                                
                                                                                
                                                                                
                                        By:                                     
                                             ------------------------------     
                                             Title:                             
                                                                                
                                                                                
                                                                                
                                        By:                                     
                                             ------------------------------     
                                             Title:                             
                                                                                
                                                                                
                                                                                
                                        THE SUMITOMO BANK, LTD., CHICAGO        
                                          BRANCH                                
                                                                                
                                                                                
                                                                                
                                        By:                                     
                                             ------------------------------     
                                             Title:                             
                                                                                
                                                                                
                                                                               



   24

                                                                              



                                     SCHEDULE 1 to the First Amendment




                                           REVISED
                                          REVOLVING
                                           CREDIT          AGGREGATE
Bank                                     COMMITMENT        VARIANCE
- ----                                  ---------------  ---------------   
                                                    
Chemical Bank                         $ 16,965,909.08  $   39,583.33
Bank of Montreal                        15,352,272.73      55,416.67
Banque Paribas                          15,352,272.73      55,416.67
Credit Lyonnais Cayman Island Branch    15,352,272.73      55,416.67
First Bank National Association         15,352,272.73      55,416.67
Fleet Bank of Massachusetts, N.A.       15,352,272.73      55,416.67
Mellon Bank, N.A.                       15,352,272.73      55,416.67
NBD Bank                                15,352,272.73      55,416.67
Bank of America Illinois                15,352,272.73      55,416.67
The Bank of Nova Scotia                 15,352,272.73      55,416.67
The Mitsubishi Trust and                15,352,272.73      55,416.67
Banking Corporation                     
ABN AMRO Bank NV                        15,352,272.73      55,416.67
The Long-Term Credit Bank of            15,352,272.73      55,416.67
Japan, Ltd. Chicago Branch              
Societe Generale                        15,352,272.73      55,416.67
Bank One, Columbus, NA                   8,772,727.27      31,666.67
Bank of Scotland                         7,272,727.27  (1,013,333.33)
Comerica Bank                            8,772,727.27      31,667.67
Caisse Nationale de Credit Agricole      8,772,727.27      31,667.67
DG Bank, Deutsche                        8,772,727.27      31,667.67
Genossenschaftsbank, Cayman
Island Branch                            
The Fuji Bank, Limited                   8,772,727.27      31,667.67
Bank of Tokyo-Mitsibishi Bank,           8,772,727.27      31,667.67
Ltd., Chicago Branch                     
The Sakura Bank, Limited                 8,772,727.27      31,667.67
The Sumitomo Bank, Ltd.,                 8,772,727.27      31,667.67
Chicago Branch                           
Banque Francaise du Commerce             6,000,000.00           0.00
Exterieur -- Cayman Island Branch        
                                       --------------  -------------       
                                       300,000,000.00           0.00






   25




                                                EXHIBIT A to the First Amendment



                                     TERM LOAN     REVOLVING CREDIT          TOTAL
BANK                                 COMMITMENT    COMMITMENT              COMMITMENT
- ----                               --------------  --------------------  --------------
                                                                
Chemical Bank                      $16,909,090.92     $16,965,909.08     $33,875,000.00       
10 South LaSalle Street
Suite 2300
Chicago, Illinois  60603
Attention: Cynthia R. Berkshire
Telephone: (312)  807-4029
Telecopy: (312)  443-1964          

Bank of Montreal                    15,272,727.27      15,352,272.73      30,625,000.00        
115 South LaSalle Street
Chicago, Illinois  60603
Attention: Irene M. Geller
Telephone: (312) 750-4368
Telecopy: (312) 750-3783           

Banque Paribas                      15,272,727.27      15,352,272.73      30,625,000.00              
227 W. Monroe Street
Suite 3300
Chicago, Illinois  60606
Attention: Jerry O'Keeke
Telephone: (312) 853-6007
Telecopy: (312) 853-6020           

Credit Lyonnais Cayman Island       15,272,727.27      15,352,272.73      30,625,000.00
Branch
227 West Monroe Street
Suite 3800
Chicago, Illinois 60606
Attention: Eric Tobin
Telephone: (312) 220-7314
Telecopy: (312) 641-0527           

First Bank National Association     15,272,727.27      15,352,272.73      30,625,000.00       
601 Second Avenue South
Minneapolis, Minnesota 55402-4302
Attention: Mark Olman
Telephone: (612) 973-1085
Telecopy: (612) 973-0825            15,272,727.27      15,352,272.73      30,625,000.00

Fleet Bank of Massachusetts, N.A.   15,272,727.27      15,352,272.73      30,625,000.00  
75 State Street
4th Floor
Boston, Massachusetts  02109
Attention: Maryann Smith
Telephone: (617) 346-1579
Telecopy: (617) 443-1964           

Mellon Bank, N.A.                  15,272,727.27      15,352,272.73       30,625,000.00       
55 West Monroe Street
Suite 2600
Chicago, Illinois  60603
Attention: Jeffrey A. Anderson
Telephone: (312) 357-3405
Telecopy: (312) 357-3414           




   26
                                                                             2
     





                                                      Revolving
                                    Term Loan           Credit                Total
Bank                                Commitment         Commitment           Commitment      
- ------                              ----------        -----------           ----------
                                                                   
NBD Bank                           15,272,727.27      15,352,272.73         30,625,000.00
First National Plaza
Mail Suite 0088
14th Floor
Chicago, Illinois  60670-0088
Attention: Donald J. Buse
Telephone: (312) 732-6620
Telecopy: (312) 732-1117           

Bank of America Illinois           15,272,727.27      15,352,272.73         30,625,000.00
231 South LaSalle Street
Chicago, Illinois 60697
Attention: Meg Claggett
Telephone: (312) 828-1549
Telecopy: (312) 765-2080          

The Bank of Nova Scotia            15,272,727.27      15,352,272.73         30,625,000.00
600 Peachtree Street N.E.
Suite 2700
Atlanta, Georgia  30308
Attention: Shannon Law
Telephone: (312) 201-4111
Telecopy: (312) 201-4108                                                        

The Mitsubishi Trust and Banking   15,272,727.27      15,352,272.73         30,625,000.00
 Corporation
520 Madison Avenue
26th Floor
New York, New York  10022
Attention: Anthony Rock
Telephone: (212) 891-8425
Telecopy: (212) 593-4691                                                       

ABN AMRO Bank NV                   15,272,727.27      15,352,272.73         30,625,000.00
135 South LaSalle Street
Chicago, Illinois 60603
Attention: Douglas Elliott
Telephone: (312) 904-2994
Telecopy: (312) 606-8425                                                        

The Long-Term Credit Bank of       15,272,727.27      15,352,272.73         30,625,000.00
Japan,
 Ltd. Chicago Branch
190 South LaSalle Street
Suite 800
Chicago, Illinois  60603
Attention: John R. Carley
Telephone: (312) 853-9516
Telecopy: (312) 704-8505                                                        

Societe Generale                   15,272,727.27      15,352,272.73         30,625,000.00
181 West Madison Street
Suite 3400
Chicago, Illinois  60602
Attention: Susan C. Hummel
Telephone: (312) 578-5157
Telecopy: (312) 578-5099                                                       



   27
                                                                              3


Caption

                                                 Revolving
                                  Term Loan        Credit           Total
                                 Commitment      Commitment       Commitment 
                                 ----------      ----------      ------------ 
                                                        
Bank One, Columbus, NA            8,727,272.73   8,772,727.27    17,500,000.00
100 East Broad Street             
7th Floor
Columbus, Ohio  43271
Attention: Douglas H. Klamfoth
Telephone: (614) 248-5839
Telecopy: (614) 248-5518          

Bank of Scotland                  8,727,272.73   8,772,727.27    17,500,000.00
181 West Madison Street
Suite 4710
Chicago, Illinois 60657
Attention: Colin J.D. Ferguson
Telephone: (312) 263-4054
Telecopy: (312) 263-1143           

Comerica Bank                     8,727,272.73   8,772,727.27    17,500,000.00
4747 West Dempster Street
Skokie, Illinois  60076
Attention: Harve C. Light
Telephone: (847) 933-2203
Telecopy: (847) 933-2209           

Caisse Nationale de Credit        8,727,272.73   8,772,727.27    17,500,000.00
Agricole 
55 East Monroe Street
Suite 4700
Chicago, Illinois 60603-5702
Attention: Roger H. Weis
Telephone: (312) 917-7440
Telecopy: (312) 372-3724           

DG Bank, Deutsche                 8,727,272.73   8,772,727.27    17,500,000.00
Genossenschaftsbank, Cayman
Island Branch
609 Fifth Avenue
New York, New York 10017
Attention: Norah E. McCann
Telephone: (212) 745-1584
Telecopy: (212) 745-1856           

The Fuji Bank, Limited            8,727,272.73   8,772,727.27    17,500,000.00
225 West Wacker Drive
Suite 2000
Chicago, Illinois 60606
Attention: Steve Peca
Telephone: (312) 621-9484
Telecopy: (312) 621-0539         

The Bank of Tokyo-,               8,727,272.73   8,772,727.27    17,500,000.00
Mitsubishi BankLtd., 
Chicago Branch
227 West Monroe Street
Suite 2300
Chicago, Illinois  60606
Attention: Wayne Yamanaka
Telephone: (312) 696-4664
Telecopy: (312) 696-4535           




   28
                                                                               4


Caption                                             Revolving
                                   Term Loan         Credit          Total
                                   Commitment      Commitment     Commitment
                                   ----------       ----------    ----------
                                                         
The Sakura Bank, Limited           8,727,272.73   8,772,727.27    17,500,000.00
227 West Monroe Street
Suite 4700
Chicago, Illinois 60606
Attention: Teresita Ladd
Telephone: (312) 201-5121
Telecopy: (312) 352-5345           

The Sumitomo Bank, Ltd.,           8,727,272.73   8,772,727.27    17,500,000.00
Chicago Branch
233 South Wacker Drive
Suite 4800
Chicago, Illinois 60606
Attention: John DiLegge
Telephone: (312) 876-6444
Telecopy: (312) 876-6436           

Banque Francaise du Commerce       6,000,000.00   6,000,000.00    12,000,000.00
Exterieur -- Cayman Island Branch
645 Fifth Avenue
New York, New York  10022
Attention: Frederick Kammler
Telephone: (212) 872-5041
Telecopy: (212) 872-5045          

                                -------------  -------------    ---------------
                                $300,000,000   $300,000,000     $600,000,000.00






   29


                                                EXHIBIT B to the First Amendment

                                                                       EXHIBIT J


                                    FORM OF
                            CAF ADVANCE CONFIRMATION



                                                    ___________, 199_



Chemical Bank, as Administrative Agent
270 Park Avenue
New York, New York  10017

     Reference is made to the Amended and Restated Credit Agreement, dated as
of July 31, 1995, among Sybron International Corporation, the Subsidiary
Borrowers, the Lenders named therein, Chase Securities Inc., as Arranger, and
Chemical Bank, as Administrative Agent (as the same may be amended,
supplemented or otherwise modified from time to time, the "Credit Agreement").
Terms defined in the Credit Agreement and used herein shall have the meanings
given to them in the Credit Agreement.

     In accordance with subsection 2.5(d) of the Credit Agreement, the
undersigned, on behalf of [itself] [One of the other Revolving Credit
Borrowers], accepts and confirms the offers by the CAF Advance Lender(s) to
make CAF advances to the undersigned on___________, 199_ under subsection
2.5(d) in the (respective) amount(s) set forth on the attached list of CAF
Advances offered.

                                      Very truly yours,

                                      [SYBRON INTERNATIONAL CORPORATION]


                                       By____________________________
                                         Title:

[NOTE:  The Parent must attach the CAF Advance offer list prepared by the
Administrative Agent with the accepted amount entered by the Parent to the
right of each CAF Advance offer].




                                      -1-
   30





                                                EXHIBIT C to the First Amendment

                                                                       EXHIBIT K

                                    FORM OF
                               CAF ADVANCE OFFER

                                                     _____________, 199__

Chemical Bank, as Administrative Agent
270 Park Avenue
New York, New York  10017

          Reference is made to the Amended and Restated Credit Agreement, dated
as of July 31, 1995, among Sybron International Corporation, the Subsidiary
Borrowers, the Lenders named therein, Chase Securities Inc., as Arranger, and
Chemical Bank, as Administrative Agent (as the same may be amended, supplemented
or otherwise modified from time to time, the "Credit Agreement"). Terms defined
in the Credit Agreement and used herein shall have the meanings given to them in
the Credit Agreement.

          In accordance with subsection 2.5 of the Credit Agreement, the
undersigned Lender offers to make CAF Advances thereunder in the following
amounts with the following maturity dates:




                                 
Borrowing Date: __________, 199__   Aggregate Maximum Amount: $_________
Maturity Date 1:                    Maximum Amount: $__________
__________, 199__                   $________ offered at _______*
                                    $________ offered at _______*
Maturity Date 2:                    Maximum Amount: $__________
__________, 199__                   $________ offered at _______*
                                    $________ offered at _______*
Maturity Date 3:                    Maximum Amount: $__________
__________, 199__                   $________ offered at _______*
                                    $________ offered at _______*

                                   
      [NOTE:  Insert the interest rate offered for the specified CAF Advance
      where indicated by an asterisk (*).  In the case of Eurodollar Rate CAF
      Advances, insert a margin bid.




                                      -1-
   31

                                                                              2




       In the case of Fixed Rate CAF Advances, insert a fixed rate bid.]

                               Very truly yours,

                               [NAME OF LENDER]


                               By_______________________
                                 Title:
                                 Telephone No.:
                                 Telecopy No.:













                

                                                   -2-
   32

                                                                              



                                                EXHIBIT D to the First Amendment

                                                                       EXHIBIT L

                                    FORM OF
                              CAF ADVANCE REQUEST

                                                   __________, 199__

 Chemical Bank, as Administrative Agent
 270 Park Avenue
 New York, New York  10017

          Reference is made to the Amended and Restated Credit Agreement, dated
as of July 31, 1995, among Sybron International Corporation, the Subsidiary
Borrowers, the Lenders named therein, Chase Securities Inc., as Arranger, and
Chemical Bank, as Administrative Agent (as the same may be amended, supplemented
or otherwise modified from time to time, the "Credit Agreement"). Terms defined
in the Credit Agreement and used herein shall have the meanings given to them in
the Credit Agreement.

          This is a [Fixed Rate] [Eurodollar Rate] CAF Advance Request pursuant
to subsection 2.5 of the Credit Agreement requesting offers for the following
CAF Advances:

          [NOTE:  Pursuant to the Credit Agreement, a CAF Advance Request may be
          transmitted in writing, by telecopy, or by telephone, immediately
          confirmed by telecopy.  In any case, a CAF Advance Request shall
          contain the information specified in the second paragraph of this
          form.]




                                              Loan 1       Loan 2       Loan 3
                                                                
Aggregate Principal Amount                  $__________  $__________  $_________
Borrowing Date
CAF Advance Maturity Date
CAF Advance Interest Payment Dates



                                             Very truly yours,

                                             [SYBRON INTERNATIONAL CORPORATION]


                                             By_______________________________
                                                Title:




                                     -1-
   33

                                                                               



                                                EXHIBIT E to the First Amendment

                                                                     EXHIBIT M-1

                            FORM OF CAF ADVANCE NOTE


                                                              New York, New York
$300,000,000                                                       July __, 1996



     FOR VALUE RECEIVED, each of the undersigned, Sybron International
Corporation ("Parent"), a Wisconsin corporation, Kerr Corporation ("Kerr"), a
Delaware Corporation, and Nalge Company ("Nalge"), a Delaware Company (each, a
"Revolving Credit Borrower"), severally, hereby unconditionally promises to pay
to the order of __________________________________ (the "Lender") at the office
of Chemical Bank located at 270 Park Avenue, New York, New York 10017, in
lawful money of the United States of America and in immediately available
funds, the principal amount of (a) THREE HUNDRED MILLION DOLLARS
($300,000,000), or, if less, (b) the aggregate unpaid principal amount of each
CAF Advance which is made by the Lender to such Revolving Credit Borrower
pursuant to subsection 2.4 of the Credit Agreement, as hereinafter defined.
The principal amount of each CAF Advance evidenced hereby shall be payable on
the CAF Advance Maturity Date therefor set forth on the schedule attached
hereto and made a part hereof or on a continuation of such schedule which shall
be attached hereto and made a part hereof (the "Grid").  Each Revolving Credit
Borrower, severally, further agrees to pay interest in like money at such
office on the unpaid principal amount of each CAF Advance made to such
Revolving Credit Lender, at the rate per annum set forth in respect of such CAF
Advance on the Grid, calculated on the basis of a year of 360 days and actual
days elapsed from the Borrowing Date of such CAF Advance until the due date
thereof (whether at the stated maturity, by acceleration or otherwise) and
thereafter at the rates determined in accordance with subsection 2.6(c) of the
Credit Agreement.  Interest on each CAF Advance evidenced hereby shall be
payable on the date or dates set forth in respect of such CAF Advance on the
Grid.  CAF Advances evidenced by this Note may not be prepaid.

     The holder of this Note is authorized to endorse on the Grid the Borrowing
Date, amount, Interest rate, Interest Payment Dates and CAF Advance Maturity
Date in respect of each CAF Advance made pursuant to subsection 2.4 of the
Credit Agreement and each payment of principal with respect thereto.  Each such
endorsement shall constitute prima facie evidence of the accuracy of the
information endorsed.  The failure to make any such endorsement shall not
affect the obligations of the Borrower in respect of such CAF Advance.

     This Note is one of the CAF Advance Notes referred to in the Amended and
Restated Credit Agreement dated as of July 31,



                                     -1-
   34

                                                                              2


1995 (as amended, supplemented or otherwise modified from time to time, the
"Credit Agreement"), among the Parent, the Subsidiary Borrowers, the Lender,
the other banks and financial institutions from time to time parties thereto,
Chemical Securities Inc., as Arranger, and Chemical Bank, as Administrative
Agent, and is subject to the provisions of the Credit Agreement.

     Upon the occurrence of any one or more of the Events of Default, all
amounts then remaining unpaid on this Note shall become, or may be declared to
be, immediately due and payable, all as provided in the Credit Agreement.

     All parties now and hereafter liable with respect to this Note, whether
maker, principal, surety, guarantor, endorser or otherwise, hereby waive
presentment, demand, protest and all other notices of any kind.

     Unless otherwise defined herein, terms defined in the Credit Agreement and
used herein shall have the meanings given to them in the Credit Agreement.

     THIS NOTE SHALL BE GOVERNED BY, AND CONSTRUED AND INTERPRETED IN
ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.

                                SYBRON INTERNATIONAL CORPORATION



                                By
                                  --------------------------------
                                  Title:


                                KERR CORPORATION



                                By
                                  --------------------------------
                                  Title:


                                NALGE COMPANY



                                By
                                  --------------------------------
                                  Title:







                                     -2-
   35

                                                                              





                            SCHEDULE OF CAF ADVANCES
                           _________________, Lender
          Sybron International Corporation, Revolving Credit Borrower
                   Credit Agreement dated as of July 31, 1995




                                                            
     Borrowing                                               CAF Advance
    Date of CAF      Amount of CAF                         Interest Payment      CAF Advance                   
     Advance           Advance            Interest Rate         Dates           Maturity Date      Payment Date   Authorization
                                                                                                      














                                      -3-
   36

                                                                               





                            SCHEDULE OF CAF ADVANCES
                           _________________, Lender
                  Kerr Corporation, Revolving Credit Borrower
                   Credit Agreement dated as of July 31, 1995




                                                          
     Borrowing                                               CAF Advance                
    Date of CAF      Amount of CAF                        Interest Payment     CAF Advance                    
     Advance           Advance            Interest Rate       Dates           Maturity Date     Payment Date   Authorization  
                                                                                                  
















                                      -4-





   37

                                                                              





                            SCHEDULE OF CAF ADVANCES
                           _________________, Lender
                    Nalge Company, Revolving Credit Borrower
                   Credit Agreement dated as of July 31, 1995




                                                            
     Borrowing                                             CAF Advance         
    Date of CAF      Amount of CAF                       Interest Payment      CAF Advance                  
     Advance            Advance        Interest Rate          Dates           Maturity Date     Payment Date    Authorization     
                                                                                                   
















                                       -5-





   38




                                                EXHIBIT F to the First Amendment
                                                                     EXHIBIT M-2



THIS QUALIFIED NON-U.S. LENDER NOTE MAY NOT BE TRANSFERRED EXCEPT IN COMPLIANCE
WITH THE TERMS AND PROVISIONS OF THE CREDIT AGREEMENT REFERRED TO BELOW.
TRANSFERS OF THIS QUALIFIED NON-U.S. LENDER NOTE MUST BE RECORDED IN THE
REGISTER MAINTAINED BY THE ADMINISTRATIVE AGENT PURSUANT TO THE TERMS OF SUCH
CREDIT AGREEMENT.


               FORM OF QUALIFIED NON-U.S. LENDER CAF ADVANCE NOTE


$300,000,000                                                      July __, 1996


     FOR VALUE RECEIVED, each of the undersigned, Sybron International
Corporation ("Parent"), a Wisconsin corporation, Kerr Corporation ("Kerr"), a
Delaware Corporation, and Nalge Company ("Nalge"), a Delaware Company (each, a
"Revolving Credit Borrower"), severally, hereby unconditionally promises to pay
to the order of __________________________________ (the "Lender") at the office
of Chemical Bank located at 270 Park Avenue, New York, New York 10017, in
lawful money of the United States of America and in immediately available
funds, the principal amount of (a) THREE HUNDRED MILLION DOLLARS
($300,000,000), or, if less, (b) the aggregate unpaid principal amount of each
CAF Advance which is made by the Lender to such Revolving Credit Borrower
pursuant to subsection 2.4 of the Credit Agreement, as hereinafter defined.
The principal amount of each CAF Advance evidenced hereby shall be payable on
the CAF Advance Maturity Date therefor set forth on the schedule attached
hereto and made a part hereof or on a continuation of such schedule which shall
be attached hereto and made a part hereof (the "Grid").  Each Revolving Credit
Borrower, severally, further agrees to pay interest in like money at such
office on the unpaid principal amount of each CAF Advance made to such
Revolving Credit Lender, at the rate per annum set forth in respect of such CAF
Advance on the Grid, calculated on the basis of a year of 360 days and actual
days elapsed from the Borrowing Date of such CAF Advance until the due date
thereof (whether at the stated maturity, by acceleration or otherwise) and
thereafter at the rates determined in accordance with subsection 2.6(c) of the
Credit Agreement.  Interest on each CAF Advance evidenced hereby shall be
payable on the date or dates set forth in respect of such CAF Advance on the
Grid.  CAF Advances evidenced by this Note may not be prepaid.

     The holder of this Note is authorized to endorse on the Grid the Borrowing
Date, amount, Interest rate, Interest Payment




   39
                                                                              2


Dates and CAF Advance Maturity Date in respect of each CAF Advance made
pursuant to subsection 2.4 of the Credit Agreement and each payment of
principal with respect thereto.  Each such endorsement shall constitute prima
facie evidence of the accuracy of the information endorsed.  The failure to
make any such endorsement shall not affect the obligations of the Borrower in
respect of such CAF Advance.

     This Note is one of the CAF Advance Notes referred to in the Amended and
Restated Credit Agreement dated as of July 31, 1995 (as amended, supplemented
or otherwise modified from time to time, the "Credit Agreement"), among the
Parent, the Subsidiary Borrowers, the Lender, the other banks and financial
institutions from time to time parties thereto, Chemical Securities Inc., as
Arranger, and Chemical Bank, as Administrative Agent, and is subject to the
provisions of the Credit Agreement.

     As provided in subsection 11.7(d) of the Credit Agreement, this Qualified
Non-U.S. Lender Note and the Obligation(s) evidenced hereby may be assigned in
whole or in part only by registration of such assignment of this Qualified
Non-U.S. Lender Note and the Obligation(s) evidenced hereby on the Register
described in subsection 11.7(c) of the Credit Agreement.  Any assignment of all
or part of such Obligation(s) and this Qualified Non-U.S. Lender Note
evidencing the same shall be registered on the Register only upon surrender for
registration of assignment of this Qualified Non-U.S. Lender Note evidencing
such Obligation(s), duly endorsed by (or accompanied by a written instrument of
assignment duly executed by) the Qualified Non-U.S. Lender Noteholder hereof,
and thereupon one or more new Qualified Non-U.S. Lender Note(s) in the same
aggregate principal amount shall be issued to the designated Assignee(s) and
the old Qualified Non-U.S. Lender Note shall be returned to the Borrower marked
"cancelled".  No assignment of this Qualified Non-U.S. Lender Note and the
Obligation(s) evidenced hereby shall be effective unless such assignment shall
have been recorded in the Register as provided herein and in subsection 11.7(d)
of the Credit Agreement.  This Qualified Non-U.S. Lender Note may not be
exchanged for promissory notes that are not Qualified Non-U.S. Lender Notes.

     Upon the occurrence of any one or more of the Events of Default, all
amounts then remaining unpaid on this Note shall become, or may be declared to
be, immediately due and payable, all as provided in the Credit Agreement.

     All parties now and hereafter liable with respect to this Note, whether
maker, principal, surety, guarantor, endorser




   40

                                                                              3

or otherwise, hereby waive presentment, demand, protest and all other notices
of any kind.

     Unless otherwise defined herein, terms defined in the Credit Agreement and
used herein shall have the meanings given to them in the Credit Agreement.

     THIS NOTE SHALL BE GOVERNED BY, AND CONSTRUED AND INTERPRETED IN
ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.

                                               SYBRON INTERNATIONAL CORPORATION



                                               By _____________________________
                                                  Title:


                                               KERR CORPORATION



                                               By _____________________________
                                                  Title:


                                               NALGE COMPANY



                                               By _____________________________
                                                  Title:





   41






                            SCHEDULE OF CAF ADVANCES
                           _________________, Lender
          Sybron International Corporation, Revolving Credit Borrower
                   Credit Agreement dated as of July 31, 1995




                                                            
     Borrowing                                             CAF Advance     
    Date of CAF     Amount of CAF                       Interest Payment    CAF Advance                    
      Advance         Advance          Interest Rate         Dates          Maturity Date   Payment Date   Authorization
                                                                                              
 

















                                      -4-
   42






                            SCHEDULE OF CAF ADVANCES
                           _________________, Lender
                  Kerr Corporation, Revolving Credit Borrower
                   Credit Agreement dated as of July 31, 1995




                                                               
     Borrowing                                            CAF Advance
    Date of CAF     Amount of CAF                       Interest Payments     CAF Advance                  
      Advacne         Advance          Interest Rate         Dates            Maturity Date      Payment Date     Authorization 
                                                                                                      



















                                      -5-
   43

                            SCHEDULE OF CAF ADVANCES
                           _________________, Lender
                    Nalge Company, Revolving Credit Borrower
                   Credit Agreement dated as of July 31, 1995




                                                              CAF Advance
     Borrowing           Amount of CAF                     Interest Payment      CAF Advance
Date of CAF Advance        Advance          Interest Rate       Dates           Maturity Date     Payment Date     Authorization
                                                                                                  






                                      -6-