AMENDMENT NO. 1 AND CONSENT
                                       TO
                         CREDIT AND GUARANTEE AGREEMENT


                  THIS AMENDMENT NO. 1 AND CONSENT ("Amendment") dated as of May
22, 1998 by and among North  American  Chemical  Company,  North  American  Salt
Company, Great Salt Lake Minerals Corporation  (collectively,  the "Borrowers"),
Harris Chemical North America,  Inc. ("HCNA"),  as guarantor  (together with the
other "Guarantors" (as defined in the Credit Agreement), the "Guarantors"),  IMC
Global  Inc.,  as the sole  Lender  (the  "Lender"),  and IMC  Global  Inc.,  as
administrative  agent (in such  capacity,  the  "Administrative  Agent")  and as
collateral  agent (in such  capacity,  the  "Collateral  Agent") for the Lender.
Capitalized terms used in this Amendment which are not otherwise defined herein,
shall have the meanings given such terms in the Credit Agreement.

                                   WITNESSETH:

                  WHEREAS,  the  Borrowers,  the  Guarantors,  the  Lender,  the
Administrative Agent and the Collateral Agent are parties to that certain Credit
and Guarantee  Agreement,  dated as of October 15, 1993, as amended and restated
as of February 27, 1997 (as the same may be amended,  restated,  supplemented or
otherwise modified from time to time, the "Credit Agreement");

                  WHEREAS,  the Borrowers have requested that the Lender and the
Administrative  Agent amend the Credit Agreement on the terms and conditions set
forth herein in order to modify  certain  covenants  contained  therein and make
certain other correlative changes resulting therefrom;

                  WHEREAS,  the Administrative  Agent and the Lender have agreed
to enter into this Amendment on the terms and conditions hereinafter set forth;

                  NOW,  THEREFORE,  in  consideration  of the premises set forth
above, the terms and conditions  contained  herein,  and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
Borrowers, the Lender and the Administrative Agent hereby agree as follows:

                  1.  Amendments  to the  Credit  Agreement.   Effective  as  of
April 1, 1998  and subject to the  satisfaction of the  conditions precedent set
forth in Section 3 below, the Credit Agreement is hereby amended as follows:

                  1.1.  Section 1 of the Credit  Agreement is hereby  amended to
delete in their entirety the  definitions of "Eligible  Inventory" and "Eligible
Receivables" now appearing therein, and to substitute the following therefor:


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                  "Eligible  Inventory":   shall  mean,  with  respect  to  the
                  relevant Borrower, an amount equal to the book value of all of
                  the inventory  ("Inventory") of such  Borrower, determined  in
                  accordance with GAAP consistently applied.

                  "Eligible  Receivables":  shall  mean,  with  respect  to  the
                  relevant Borrower, an amount equal to the book value of all of
                  the  accounts  receivable   ("Accounts")  of  such   Borrower,
                  determined in accordance with GAAP consistently applied.

                  1.2.  Sections 9.2(a),  (b), (c), (d) and (f), 9.5(c) and 9.10
of the Credit  Agreement are hereby  deleted in their entirety and of no further
force and effect.

                  1.3.  Section 9.2(e) of the Credit Agreement is hereby amended
to delete the phrase "each of (i) the end of the first two weeks of each Interim
Accounting Period and (ii)" now appearing therein.

                  1.4.     Section 10 of the  Credit Agreement is hereby deleted
in its entirety and of no further force and effect.

                  1.5.     Section 12 of the Credit Agreement is hereby deleted
in its entirety and the following is substituted therefor:

                  "If any of the following events shall occur and be continuing:

                           (a)  any  Borrower  shall  fail to pay  when  due any
                  principal of any Loan or any L/C Obligation,  or shall fail to
                  pay,  within  five (5)  Business  Days after  notice  from the
                  Administrative Agent, any interest,  fees, or any other amount
                  payable hereunder;

                           (b) any Borrower shall fail to observe or perform any
                  covenant or agreement  contained in this  Agreement for thirty
                  (30) days after notice thereof has been given to such Borrower
                  by the Administrative Agent; or

                           (c)  (i)  HCNA  or  any  of  its  Subsidiaries  shall
                  commence any case,  proceeding  or action,  or (in the case of
                  any  Canadian  Subsidiary)  file  a  notice  of  intention  to
                  commence  any of the  foregoing,  (A)  under any  existing  or
                  future law of any jurisdiction,  domestic or foreign, relating
                  to  bankruptcy,   insolvency,   reorganization  or  relief  of
                  debtors,  seeking  to have an order for  relief  entered  with
                  respect  to it, or  seeking to  adjudicate  it a  bankrupt  or
                  insolvent or seeking reorganization,  arrangement, adjustment,
                  winding-up,  liquidation,  dissolution,  composition  or other
                  relief  with  respect  to it or  its  debts,  or  (B)  seeking
                  appointment of a receiver, trustee, custodian,  conservator or
                  other  similar  official for it or for all or any  substantial
                  part of its assets,  or HCNA or any of its Subsidiaries  shall
                  make a general assignment for the benefit of its creditors; or
                  (ii)  there  shall  be  commenced  against  HCNA or any of its
                  Subsidiaries  any  case,  proceeding  or  action  of a  nature
                  referred to in clause (i) above which (A) results in the entry
                  of an order for relief or any such adjudication or appointment
                  or (B) remains  undismissed,  undischarged  or unbonded  for a
                  period of 60 days; or

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                  (iii)  there  shall be  commenced  against  HCNA or any of its
                  Subsidiaries  any case,  proceeding  or other  action  seeking
                  issuance of a warrant of attachment,  execution,  distraint or
                  similar  process  against all or any  substantial  part of its
                  assets  which  results  in the  entry of an order for any such
                  relief  which  shall not have  been  vacated,  discharged,  or
                  stayed or bonded  pending appeal within 60 days from the entry
                  thereof;  or (iv) HCNA or any of its  Subsidiaries  shall take
                  any action in  furtherance  of, or indicating  its consent to,
                  approval of, or acquiescence  in, any of the acts set forth in
                  clause (i),  (ii),  or (iii) above;  or (v) HCNA or any of its
                  Subsidiaries  shall  generally  not, or shall be unable to, or
                  shall admit in writing its inability to, pay its debts as they
                  become due or otherwise be insolvent  under  applicable law of
                  any jurisdiction;

                           then, and in any such event,  (A) if such event is an
                  Event of  Default  specified  in clause (i) or (ii) of Section
                  12(c) above with respect to any  Borrower,  automatically  the
                  Commitments   shall   immediately   terminate  and  the  Loans
                  hereunder  (with  accrued  interest  thereon)  and  all  other
                  amounts  owing  under  this  Agreement   (including,   without
                  limitation, all amounts of L/C Obligations, whether or not the
                  beneficiaries of the then outstanding  Letters of Credit shall
                  have  presented the  documents  required  thereunder)  and the
                  Loans shall  immediately  become due and  payable,  and (B) if
                  such event is any other  Event of  Default,  either or both of
                  the  following  actions may be taken:  (i) with the consent of
                  the Aggregate Required Lenders,  the Administrative Agent may,
                  or upon the request of the  Aggregate  Required  Lenders,  the
                  Administrative Agent shall, by notice to the Borrowers declare
                  the  Commitments  to  be  limited,  restricted  or  terminated
                  forthwith,  whereupon the Commitments  shall immediately so be
                  limited,  restricted or terminated;  and (ii) with the consent
                  of the Aggregate Required Lenders,  the  Administrative  Agent
                  may, or upon the request of the  Aggregate  Required  Lenders,
                  the  Administrative  Agent shall,  by notice to the Borrowers,
                  declare the Loans  hereunder (with accrued  interest  thereon)
                  and all other amounts owing under this  Agreement  (including,
                  without limitation, all amounts of L/C Obligations, whether or
                  not the  beneficiaries  of the  then  outstanding  Letters  of
                  Credit shall have presented the documents required thereunder)
                  and the Loans to be due and payable  forthwith,  whereupon the
                  same shall immediately become due and payable (the date of any
                  termination or declaration referred to in this paragraph,  the
                  "Acceleration Date")."

                  Except  as  expressly  provided  above  in  this  Section  12,
presentment,  demand,  protest  and all  other  notices  of any kind are  hereby
expressly waived.

                  2. Consent.  Each of the  Administrative  Agent and the Lender
hereby consent to permit each of HCNA and/or Sifto Canada,  Inc., as applicable,
to make one or more offers to purchase the Public Debt, provided each such offer
is made no later than December 31, 1998.

                  3.  Conditions  of  Effectiveness  of  this  Amendment.   This
Amendment  shall become  effective  and be deemed  effective as of April 1, 1998
(the  "Effective  Date"),  if, and only if the  Administrative  Agent shall have
received duly  executed  originals of this  Amendment  from the  Borrowers,  the
Guarantors, the Administrative Agent, the Collateral Agent and the Lender.


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                  4.  Representations  and Warranties of the  Borrowers and  the
Guarantors.  The  Borrowers and the  Guarantors hereby represent  and warrant as
follows:

                  (a) This  Amendment  and the Credit  Agreement  as  previously
executed and as amended hereby,  constitute legal, valid and binding obligations
of the Borrowers and the  Guarantors and are  enforceable  against the Borrowers
and the Guarantors in accordance with their terms.

                  (b) Upon the  effectiveness  of this Amendment,  the Borrowers
and the Guarantors hereby reaffirm all covenants, representations and warranties
made in the Credit  Agreement  to the extent  the same are not  amended  hereby,
agree that all such covenants, representations and warranties shall be deemed to
have been remade as of the effective date of this Amendment.

                  5.  Reference to the Effect on the Credit Agreement.

                  (a) Upon the  effectiveness of Section 1 hereof,  on and after
the date hereof,  each  reference in the Credit  Agreement to "this  Agreement,"
"this Credit Agreement," "hereunder," "hereof," "herein" or words of like import
shall mean and be a reference to the Credit Agreement as amended hereby.

                  (b) Except as specifically amended above, the Credit Agreement
and all other documents, instruments and agreements executed and/or delivered in
connection  therewith,  shall  remain in full force and  effect,  and are hereby
ratified and confirmed.

                  (c)  The  execution,   delivery  and   effectiveness  of  this
Amendment shall not, except as expressly provided herein, operate as a waiver of
any  right,  power or  remedy of the  Administrative  Agent or the  Lender,  nor
constitute  a waiver  of any  provision  of the  Credit  Agreement  or any other
documents,  instruments and agreements  executed and/or  delivered in connection
therewith.

                  6.  Headings.  Section headings in this Amendment are included
herein for convenience of reference only and shall not constitute a part of this
Amendment for any other purpose.

                  7.  Counterparts.  This  Amendment may be  executed by  one or
more of the parties to the Amendment on any number of separate  counterparts and
all of said  counterparts taken  together shall be deemed to  constitute one and
the same instrument.

                  8. Entire Agreement.  This Amendment,  taken together with the
Credit  Agreement  and all of the other  Loan  Documents,  embodies  the  entire
agreement  and  understanding  of the parties  hereto and  supersedes  all prior
agreements and understandings,  written and oral, relating to the subject matter
hereof.

                  9.  Governing Law.  This  Amendment shall be  governed by  and
construed in accordance with the internal laws of the State of New York.



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                  IN WITNESS  WHEREOF,  this Amendment has been duly executed as
of the day and year first above written.


                        NORTH AMERICAN SALT COMPANY,
                         as Borrower and as Guarantor


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title: Vice President


                        NORTH AMERICAN CHEMICAL COMPANY,
                         as Borrower and as Guarantor


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title: Vice President


                        GREAT SALT LAKE MINERALS CORPORATION,
                         as Borrower and as Guarantor


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title: Vice President


                        IMC GLOBAL INC., as Administrative Agent,
                         Collateral Agent and as Lender


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title:  Sr. Vice President and Chief Executive Officer


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Acknowledged and agreed as of the 22d day of May, 1998:

                        HARRIS CHEMICAL NORTH AMERICA
                         INC., as Guarantor


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title: Vice President


                        NAMSCO, INC., as Guarantor


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title: Vice President


                        CAREY SALT COMPANY, as Guarantor


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title: Vice President


                        GSL CORPORATION, as Guarantor


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title: Vice President


                        GSL HOLDINGS, INC., as Guarantor


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title: Vice President


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                        THE HUTCHINSON & NORTHERN RAILWAY
                         COMPANY, as Guarantor


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title: Vice President


                        NORTH AMERICAN TERMINALS, INC.,
                         as Guarantor


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title: Vice President


                        OLDEXAER, INC., as Guarantor


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title: Vice President


                        WRNM HOLDINGS, INC., as Guarantor


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title: Vice President


                        WHITE RIVER NAHCOLITE MINERALS
                         LIMITED LIABILITY COMPANY, as
                         Guarantor


                        By: /s/ J. Bradford James
                          Name:  J. Bradford James
                          Title: Vice President


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