<PAGE>   1
                                                                   Exhibit 10.40


                          AMENDMENT TO CREDIT AGREEMENT
                                   AND CONSENT

         AMENDMENT TO CREDIT AGREEMENT AND CONSENT, dated as of May 18, 1999,
among EAGLE-PICHER INDUSTRIES, INC., a Delaware corporation and successor by
merger to E-P ACQUISITION, INC., a Delaware corporation (together herein
collectively referred to as the "Borrower"), the lenders party hereto (each a
"Lender" and collectively, the "Lenders"), ABN AMRO BANK N.V., as Agent (in such
capacity, the "Agent"), PNC BANK, NATIONAL ASSOCIATION, as Documentation Agent
(in such capacity, the "Documentation Agent") and NBD BANK, N.A., as Syndication
Agent (in such capacity, the "Syndication Agent").


                              W I T N E S S E T H:

         WHEREAS, the Borrower, the Lenders, the Agent, the Documentation Agent
and the Syndication Agent are parties to that certain Credit Agreement, dated as
of February 19, 1998, as modified by (i) that certain Eagle-Picher Industries,
Inc. Credit Agreement Consent and Waiver among the Borrower, the Agent and the
Lenders party thereto, dated as of November 18, 1998 and (ii) that certain
Eagle-Picher Industries, Inc. Credit Agreement Amendment and Consent among the
Borrower, the Agent and the Lenders party thereto dated as of December 14, 1998,
(together the "Credit Agreement"); and

         WHEREAS, the Borrower has requested that the Credit Agreement be
further amended in certain respects; and

         WHEREAS, the Lenders and the Agents party hereto, are willing to so
further amend the Credit Agreement, subject to the terms and conditions
hereinafter set forth;

         NOW, THEREFORE, the parties hereto, in consideration of their mutual
covenants and agreements hereinafter set forth and intending to be legally bound
thereby, covenant and agree as follows:

          1. General. All terms used herein which are not otherwise specifically
defined herein shall have the same meaning herein as defined in the Credit
Agreement as further amended hereby.

          2. Increase in Total Revolving Credit Commitment. Section 1.01.01(d)
of the Credit Agreement shall be and is hereby amended by deleting the amount of
"$160,000,000" appearing in the last sentence thereof and inserting in its place
the amount of "$220,000,000." Furthermore, Annex I to the Credit Agreement shall
be and is hereby deleted and the Annex I (Amended) attached hereto shall be
inserted in its place.

          3. Interest. With respect to the rate of interest provided under
Section 1.08 and the Applicable Base Rate Margin and Applicable Eurodollar Rate
Margin as determined pursuant to the Pricing Grid, Annex II to the Credit
Agreement shall be and is hereby amended by adding

<PAGE>   2




".25" to each amount set forth in such Annex II under the headings "Applicable
Eurodollar Rate Margin" and "Applicable Base Rate Margin."

          4. Letter of Credit. Section 2.01(b) of the Credit Agreement shall be
and is hereby amended by inserting after the words "identified on Schedule 2.01"
in line 10 the following wording:

                  "(or as determined by the Agent with respect to future standby
                  Letters of Credit)"

          5. Mandatory Prepayments and Repayments.

                  (a) Section 4.02.01(c) of the Credit Agreement shall be and is
         hereby amended by (i) deleting the amount of "$25,000,000" appearing
         therein and inserting in its place the amount of "$50,000,000," and
         (ii) by deleting the phrases "270 days" and "270 day" wherever they
         appear therein and inserting in their place, the phrases "360 days" and
         "360 day", respectively.

                  (b) Section 4.02.01(f) of the Credit Agreement shall be and is
         hereby amended by (i) deleting the percentage "60%" appearing therein
         and inserting in its place, the percentage "50%" and (ii) by deleting
         the period at the end thereof and inserting the following language in
         its place:

                   ", provided, however, that should the Borrower maintain a
                  Leverage Ratio of not more than 3.50 to 1.00 on the last day
                  of four consecutive fiscal quarters of the Borrower, the
                  requirements of this Section shall thereupon no longer be in
                  effect as to any Excess Cash Payment Date thereafter
                  occurring."

          6. Use of Proceeds. Section 6.08(a) of the Credit Agreement shall be
and is hereby amended by deleting the following wording in lines 5 and 6
thereof: "(excluding acquisitions)".

          7. Year 2000. Section 6 of the Credit Agreement shall be and is hereby
amended by adding a new Section 6.25 reading as follows:

                  "Section 6.25. Year 2000. The Borrower and its Subsidiaries
                  have reviewed the areas within their business and operations
                  which could be adversely affected by, and have developed or
                  are developing a program to address on a timely basis, the
                  "Year 2000 Problem" (that is, the risk that computer
                  applications used by the Borrower and its Subsidiaries may be
                  unable to recognize and perform properly date-sensitive
                  functions involving certain dates prior to and any date after
                  December 31, 1999), and have made related appropriate inquiry
                  of material suppliers and vendors. Based on such review and
                  program, the Borrower believes that the


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                  "Year 2000 Problem" will not have a material adverse effect on
                  the business, operations, property or financial or other
                  condition of the Borrower and its Subsidiaries taken as a
                  whole."

          8. Information Covenants. Section 7.01 of the Credit Agreement shall
be and is hereby amended by (i) deleting from line 6 and 7 of Subsection 7.01(a)
the phrase "and comparable budgeted figures for such fiscal month", (ii)
inserting in line 8 of Subsection 7.01(b) after the word "year" and before the
comma the phrase "and comparable budgeted figures for such quarterly accounting
periods,", (iii) deleting from line 5 and 6 of Subsection 7.01(d) the phrase
"income, and sources and uses of cash and balance sheets" and inserting in its
place the phrase "net sales, Consolidated EBITDA and operating income", (iv)
inserting in line 6 of Subsection 7.01(d) after the word "whole" and before the
parenthesis the phrase "in the format as currently prepared by the Borrower",
(v) deleting from line 12 of Subsection 7.01(d) the reference "(a),", (vi)
adding to line two of Subsection 7.01(e) the words "or other Authorized Officer"
after the words "chief financial officer", (vii) deleting from line 10 of
Subsection 7.01(e) the reference to parens "(i)" and deleting all wording
appearing after the words "fiscal year" in line 12 of Subsection 7.01(e) and
inserting an ending period in place thereof, and (viii) by adding a new
subsection 7.01(l) reading as follows:

                  "(l) Year 2000. Statements of financial performance and
                  compliance certificates required to be provided by the Company
                  and/or its Subsidiaries to the Bank herein shall: (i) include
                  a statement as to whether the Year 2000 remediation efforts of
                  the Company and its Subsidiaries are proceeding as scheduled
                  and (ii) indicate whether an auditor, regulator, or third
                  party consultant has issued a management letter or other
                  communication regarding the Year 2000 exposure, program or
                  progress of the Borrower and/or its Subsidiaries."

          9. Maintenance of Property, Insurance, Environmental Matters, etc.
Section 7.03(b) of the Credit Agreement shall be and is hereby amended by
inserting the following wording in line 11 thereof after the words "as set forth
in Schedule 6.13" and before the semi-colon:

                  "and except for landfills or dumps operated by the Borrower or
                  its Subsidiaries on their own properties solely for the
                  disposal of waste filter materials which are not Hazardous
                  Materials and which are used in the operations of the Borrower
                  or its Subsidiaries and which landfills or dumps are not used
                  for the disposal of any waste or materials from Persons other
                  than the Borrower or its Subsidiaries"

         10. Consolidation, Merger, Sale of Assets. Section 8.02 of the Credit
Agreement shall be and is hereby amended by (a) deleting the amount of
"$25,000,000" appearing in clause (iv) thereof and inserting in its place, the
amount of "$50,000,000" and (b) deleting the word "and" at

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the end of clause (vi) and (c) deleting the period after clause (vii) thereof
and replacing it with a semi-colon and (d) adding the following additional
clauses to Section 8.02:

                    "(viii) transactions permitted by Section 8.05 of this
                  Agreement; (ix) reinvestments of the proceeds of Asset Sales
                  pursuant to Section 4.02.01(c), and (x) the sale of
                  receivables in connection with the Permitted Securitization."

         11. Indebtedness. Section 8.04 of the Credit Agreement shall be and is
hereby amended by (i) inserting after the words "Senior Subordinated Note
Indenture" appearing in clause (vi), line 12, the words "or other Senior
Subordinated Note Indentures meeting the requirements of (A) above," (ii)
deleting the amount of "$220,000,000" appearing in such line 12 and inserting in
its place the amount of "$295,000,000", (iii) inserting in front of the word
"Indebtedness" appearing in clause (vii) thereof, the word "unsecured" and by
deleting the amount of "$25,000,000" appearing therein and inserting in its
place, the amount of "$35,000,000" and (iv) deleting the word "and" at the end
of clause (vii) and by deleting the period after clause (viii) thereof and by
replacing it with a semi-colon and by adding the following additional clauses to
Section 8.04:

                  "(ix) the Permitted Securitization; and

                  (x) unsecured Indebtedness assumed in connection with
         Permitted Acquisitions."

         12. Advances, Investments and Loans. Section 8.05 of the Credit
Agreement shall be and is hereby amended by (i) deleting the word "and" after
clause (vii) thereof, by (ii) deleting the period at the end of clause (viii)
thereof and by replacing it with "; and" and (iii) by adding a new clause (ix)
reading as follows:

                  "(ix) Permitted Acquisitions, Permitted Investments and
         Permitted Minority Investments."

         13. Capital Expenditures. Section 8.07 shall be and is hereby amended
by deleting the amount of "$40,000,000" set forth in Subsection 8.07(a) and
inserting in its place the amount of "$50,000,000."

         14. Limitation on Voluntary Payments and Modifications of Indebtedness;
Modifications of Certificate of Incorporation, By-laws and Certain Other
Agreements; Issuances of Capital Stock, etc. Section 8.11 of the Credit
Agreement shall be and is hereby amended by striking the period at the end
thereof and inserting the following language in its place:

                  "; provided, however, that, so long as the Leverage Ratio on
                  the last day of the fiscal quarter most recently ending prior
                  to each payment or purchase shall be not more than 3.50 to
                  1.00 and there shall not then exist any Default or Event of
                  Default hereunder, the

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<PAGE>   5

                  Borrower may pay or purchase the Senior Subordinated Notes up
                  to an aggregate principal amount for all such payments and
                  purchases not exceeding $25,000,000."

         15. Limitation on Issuances of Capital Stock by Subsidiaries. Section
8.13 of the Credit Agreement shall be and is hereby amended by deleting the
period at the end thereof and inserting the following language in its place:

                  "and except that any Subsidiary that is not a Subsidiary
                  Guarantor may issue shares of capital stock, provided that
                  such issuance shall be deemed an Asset Sale for purposes of
                  Section 4.02.01(c) and Section 8.02(iv)."

         16. Limitation on the Creation of Subsidiaries. Section 8.14 of the
Credit Agreement shall be and is hereby amended by (i) inserting after the words
"provided that" in line four thereof, the following "(A)" and (ii) deleting the
period at the end of the first sentence of Section 8.14 and adding in its place
the following:

                  ", and (B) the Borrower and its Wholly-Owned Subsidiaries
                  shall be permitted to create, establish or acquire
                  Subsidiaries that are not Wholly-Owned Subsidiaries, provided
                  that any purchase of capital stock of or capital contribution
                  or loan to any such Subsidiary shall be subject to the
                  restrictions contained in Section 8.05."

         17. Events of Default. Section 9.03 of the Credit Agreement shall be
and is hereby amended by deleting the present wording thereof and inserting in
its place the following:

                           "Section 9.03. Covenants. The Borrower shall (i)
                  default in the due performance or observance by it of any
                  term, covenant or agreement contained in Sections 7.02,
                  7.09(h), 8.02, 8.03, 8.08 through, and including, 8.13 and
                  8.16, (ii) default in the due performance or observance by it
                  of any term, covenant or agreement contained in Sections 7.01,
                  7.10 or 8.06 and such default shall continue unremedied for a
                  period of 10 days after written notice to the Borrower by the
                  Agent or the Required Lenders or (iii) default in the due
                  performance or observance by it of any term, covenant or
                  agreement (other than those covered by Sections 9.01 and 9.02
                  and clauses (i) and (ii) of this Section 9.03) contained in
                  this Agreement and such default shall continue unremedied for
                  a period of 30 days after written notice to the Borrower by
                  the Agent or the Required Lenders; or"

         18. Definitions. Section 10.01 of the Credit Agreement shall be and is
hereby amended as follows:

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                  (a) There shall be added the following new definitions to be
         inserted in proper alphabetical order reading as follows:

                  "Acquisition" means any transaction, or any series of related
                  transactions, consummated on or after the date hereof, by
                  which the Borrower or any of its Subsidiaries (i) acquires any
                  going business or all or substantially all of the assets of
                  any firm, corporation or division thereof, whether through
                  purchase of assets, merger or otherwise or (ii) directly or
                  indirectly acquires (in one transaction or as the most recent
                  transaction in a series of transactions) at least a majority
                  (in number of votes) of the securities of a corporation which
                  have ordinary voting power for the election of directors
                  (other than securities have such power only by reason of the
                  happening of a contingency) or a majority (by percentage of
                  voting power) of the outstanding equity, partnership or
                  membership interests of another Person.

                  "Permitted Acquisition" means Acquisitions by the Borrower or
                  any of its Subsidiaries, provided that (A) the total
                  consideration payable in connection therewith, whether in the
                  form of cash, notes or indebtedness assumed, together with the
                  amount of any Permitted Investments, shall not exceed the
                  aggregate amount of $75,000,000 in any fiscal year of the
                  Borrower, (B) no Default or Event of Default has occurred and
                  is continuing or would result therefrom, (C) the Acquisition
                  shall be consummated pursuant to a negotiated acquisition
                  agreement on a non-hostile basis, (D) the Borrower can
                  demonstrate that, on a pro forma basis, after giving effect to
                  such Acquisition, it will continue to comply with all the
                  terms and conditions of the Credit Agreement and (E) the
                  property acquired shall become collateral in accordance with
                  Section 7.09 hereof, provided further, however, that should
                  the Borrower maintain a Leverage Ratio of not more than 3.50
                  to 1.00 on the last day of four consecutive fiscal quarters of
                  the Borrower, the foregoing proviso (A) shall no longer be in
                  effect as to any Acquisition occurring thereafter, and the
                  Borrower need comply only with provisos (B), (C), (D) and (E)
                  as to any such Acquisition.

                  "Permitted Investments" means any equity investment in or
                  capital contribution or loan to any Subsidiary other than a
                  Wholly-Owned Subsidiary, provided that the aggregate amount of
                  such equity investments, contributions or loans, together with
                  the amount of any Permitted Acquisitions, shall not exceed the
                  aggregate amount of $75,000,000 in any fiscal year of
                  Borrower.

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<PAGE>   7

                  "Permitted Joint Ventures" means (A) any joint venture
                  interests described on Schedule 8.05, and (B) any Subsidiaries
                  other than Wholly-owned Subsidiaries that are formed or
                  acquired in accordance with Sections 8.02, 8.05 and 8.14.

                  "Permitted Minority Investment" means any equity investment in
                  or capital contribution or loan to any Person not a Subsidiary
                  so long as the aggregate amount of such equity investments and
                  capital contributions does not exceed $15,000,000 and any loan
                  shall be on terms requiring the cash payment of interest at
                  least annually.

                  "Permitted Securitization" means any sales from time to time
                  by the Borrower or its Subsidiaries of its receivables, taking
                  the form of a "true sale" to a special purpose vehicle ("SPV")
                  to be formed by the Borrower and a subsequent sale and/or
                  financing by the SPV to, or with, a Person or Persons who are
                  not Affiliates of Borrower, provided that the terms and
                  provisions relative thereto, including, without limitation,
                  the advance rates against such receivables, shall be
                  reasonably acceptable to the Agent.

                  b) The definition of "Asset Sale" shall be and is hereby
         amended by (i) deleting the word "and" appearing in front of clause
         (ii) thereof, replacing it with a comma, and (ii) by deleting the
         period at the end of such definition and inserting in its place the
         following:

                  "and (iii) any sale of receivables pursuant to the Permitted
                  Securitization."

                  (c) The definition of "Consolidated EBIT" shall be and is
         hereby amended by adding the following language at the end thereof:

                  "If any Person or assets were acquired during a Test Period in
                  an Acquisition permitted by Section 8.05, then the
                  consolidated net income of such Person or attributable to such
                  assets (adjusted for the foregoing items (i) through (v)) for
                  the period beginning on the beginning of the Test Period and
                  ending on the date of the Acquisition shall be included in
                  Consolidated EBIT, but only to the extent that such items of
                  such Person or attributable to such assets would have been
                  available to the Borrower or its Subsidiary had the Borrower
                  or such Subsidiary acquired such Person or such assets at the
                  beginning of such period."

                  (d) The definition of "Consolidated EBITDA" shall be amended
         by deleting the period at the end thereof and adding the following
         language:

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<PAGE>   8

                  ", in computing Consolidated EBITDA, any of the foregoing
                  items realized or accrued for any Test Period and which
                  occurred prior to the date of any acquisition permitted by
                  Section 8.05(ix) by the Person so acquired, or attributable to
                  the assets so acquired shall be included in Consolidated
                  EBITDA, but only to the extent that such items of such Person
                  or attributable to such assets would have been available to
                  the Borrower or its Subsidiary had the Borrower or such
                  Subsidiary acquired such Person or such assets at the
                  beginning of such period. There shall also be included in
                  Consolidated EBITDA any cash interest and dividends received
                  by the Borrower or its Subsidiaries during any Test Period
                  with respect to investments and loans made by the Borrower or
                  its subsidiaries to joint ventures permitted by Section 8.05
                  hereof."

                  (e) The definition of "Consolidated Interest Expense" shall be
         amended by inserting in line 5 thereof after the words "including,
         without limitation," the following language:

                  "all such interest expense, amortization of debt discount,
                  fees and all debt issuance costs incurred in connection with
                  the Permitted Securitization and"

                  (f) The definition of "Indebtedness" shall be and is hereby
         amended by (i) deleting the word "and" in front of clause (vii),
         inserting in its place a comma and (ii) by deleting the period at the
         end thereof and inserting in its place the following wording:

                  "and (viii) the aggregate face value of outstanding commercial
                  paper or other obligations issued in respect of the Permitted
                  Securitization or, in the event of any funding by Persons
                  providing liquidity support in the form of loans or asset
                  purchase arrangements, the aggregate principal amount of such
                  funding."

                  (g) The definition of "Subsidiary" shall be and is hereby
         amended by deleting the period at the end thereof and inserting in its
         place the following wording:

                  "provided, however, that any Permitted Joint Venture described
                  on Schedule 8.05 or formed or acquired in accordance with
                  Sections 8.02, 8.05 and 8.14 shall not be included within the
                  term Subsidiary."

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<PAGE>   9

         19.    Syndication Agent.

         All references in the Credit Agreement to "DLJ Capital Funding, Inc.,
as Syndication Agent" shall be and is hereby deleted and amended and deemed to
be "NBD BANK, N.A., as Syndication Agent".

         20. Payment of B and C Lenders and Adjustment of Revolving Loans.

                  (a) Upon the Effective Date, as hereinafter defined, of this
         Amendment, the Borrower shall prepay the B and C Term Loans in full
         together with all accrued interest thereon to the date of prepayment
         and all other amounts due and payable in respect of the B and C Term
         Loans hereunder. The Lenders with outstanding A Term Loans hereby
         consent to such prepayment and waive, as to such prepayment, the
         requirement of Section 4.01 that prepayments of Term Loans shall be
         made pro-rata among the A Term Loans, B Term Loans and C Term Loans.

                  (b) Upon the Effective Date of this Amendment, the Revolving
         Credit Commitment shall be increased as provided in Annex I attached
         hereto provided each such new Lender shall execute and deliver to the
         Agent a joinder to the Credit Agreement in the form of Exhibit I hereto
         (and by such execution and delivery, each such new Lender shall be
         deemed to have agreed with the matters set forth in the Credit
         Agreement as amended hereby). Such new Lender shall become a Lender
         hereunder, and the Agent shall, promptly following the effective date
         thereof, provide to the Borrower and the Lenders the revised Revolving
         Percentage giving effect to Annex I (Amended) attached hereto. The
         Borrower agrees that it shall execute and deliver to Lenders whose
         Revolving Credit Commitment has changed, a Revolving Note evidencing
         such Lender's revised Revolving Credit Commitment.

                  (c) If, after giving effect to the Revolving Credit Commitment
         Increase, any Lender's revised Revolving Percentage of the Revolving
         Credit Commitment is different than its share of the Revolving Loans,
         the Revolving Loans shall be reallocated among the Lenders as follows.
         On the Effective Date, the Borrower shall be deemed to have prepaid all
         outstanding Revolving Loans in accordance with Section 4.01 of the
         Credit Agreement and reborrowed all Revolving Credit Loans in
         accordance with Section 1.01.01(d) of the Credit Agreement from all
         Lenders ratably in accordance with their revised Revolving Percentage.
         Each Lender having a decreased Revolving Percentage (a "Selling
         Lender") agrees to sell and assign to each other Lender (each a "Buying
         Lender"), and each Buying Lender hereby agrees to ratably purchase and
         assume, without recourse, from each Selling Lender, a ratable portion
         of each Selling Lender's Revolving Loans such that, after giving effect
         to such assignments, each Lender's share of all Revolving Loans equals
         its revised Revolving Percentage. The Agent shall distribute to each
         Selling Lender an amount equal to the difference between its Revolving
         Loans so prepaid and the new Revolving Loans deemed to have been made
         by it. Such payments shall be deemed to be a payment of the Revolving
         Loans by the Borrower on the date such payment is received. With
         respect to each portion of the


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<PAGE>   10

         Revolving Loans and Letter of Credit Obligations reapportioned as
         described above, interest and fees accruing thereon for the period
         prior to the date hereof shall be for the account of each Selling
         Lender, and interest and fees accruing thereon for the period from and
         after the date hereof shall be for the account of each Buying Lender.
         The Borrower shall compensate each Lender for any loss, cost or expense
         caused by such prepayment in accordance with Section 1.11 of the Credit
         Agreement.

         21. Technologies Consent. The undersigned Lenders do hereby consent to
(i) the ground lease of a portion of the vacant land owned by Eagle-Picher
Technologies, LLC ("Technologies") in the Joplin Industrial Park, Joplin,
Missouri to Joplin Design & Management, Inc. ("Joplin"), (ii) the lease by
Technologies from Joplin of a building to be constructed on such land and (iii)
the subordination of the mortgage lien on such land in favor of the Agent to the
ground lease, all as described in the Information Memorandum circulated in
connection with this Amendment and Consent and do hereby waive any Default or
Event of Default that may arise under Sections 8.01, 8.02 or 8.04 of the Credit
Agreement as a result thereof.

         22. Waiver of Mandatory Repayment. The undersigned Lenders hereby waive
the mandatory repayment requirements of Section 4.02.01(d) of the Credit
Agreement as it relates to the incurrence of additional Indebtedness under the
other Senior Subordinated Note Indentures permitted by this Amendment and
Consent.

         23. Conditions. The Effective Date of this Amendment shall be subject
to the satisfaction of the following conditions precedent:

                  (i) This Amendment shall have been executed by each Credit
         Party, each of the Agents and each of the Lenders with outstanding A
         Term Loans.

                  (ii) The Agent shall have received an opinion of counsel
         addressed to the Agent and each of the Lenders from Howard, Smith &
         Levin relative to the power and authority of the Borrower to enter into
         this Amendment and the legal validity thereof.

                  (iii) A certified copy of resolutions of the Borrower
         authorizing this Amendment, together with a certified officer
         incumbency and specimen signature certificate.

                  (iv) The payment of all fees and expenses (including, without
         limitation, all legal fees and expenses) due to the Agent and the Banks
         and special legal counsel to the Agent.

                  (v) The Permitted Securitization shall be closed.

                  (vi) The conditions to each Credit Event as set forth in
         Section 5.02 of the Credit Agreement shall have been met.

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<PAGE>   11

         24. Effectiveness. Subject to Section 23 hereof, this Amendment shall
become effective on the date on which each Credit Party and each of the Lenders
with outstanding A Term Loans shall have signed a counterpart hereof and shall
have delivered the same to the Agent (herein, the "Effective Date"), provided,
however, that upon the Effective Date of this Amendment, the amendment to the
definition of Consolidated EBIT as provided herein shall be deemed effective as
of the date of the Credit Agreement. The Agent shall give the Borrower and each
Lender prompt written notice of the effective date. This Amendment may be
executed in any number of Counterparts and by the different parties hereto on
separate counterparts, each of which when so executed and delivered shall be an
original, but all of which shall together constitute one and the same
instrument. A set of counterparts executed by all the parties hereto shall be
lodged with the Borrower and the Agent. This Amendment and the rights and
obligations of the parties hereunder shall be construed in accordance with and
be governed by the law of the State of New York. Except as herein specifically
amended, the Credit Agreement shall be and remain in full force and effect and
wherever reference is made in any note, document, letter or other communication
to the Credit Agreement, such reference shall, without more, be deemed to refer
to the Credit Agreement as amended hereby. The consent and waiver provided in
paragraphs 21 and 22 hereof shall be limited specifically as provided for
therein and this Amendment and Consent shall not constitute a consent to any
other transaction or waiver of the application of the Sections of the Credit
Agreement referred to in paragraphs 21 and 22 hereof to any other transaction
nor shall it be a waiver or modification of any other term, provision or
condition of the Credit Agreement or waiver of any Default or Event of Default
except as expressly set forth herein and shall not prejudice or be deemed to
prejudice any right that the Agent or any Lender may now have or may have in the
future under the Credit Agreement.


                           [SIGNATURE PAGES TO FOLLOW]


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<PAGE>   12




         IN WITNESS WHEREOF, the parties hereto have caused their duly
authorized officers to execute and deliver this Amendment and Consent as of the
date first above written.

Address:

250 East Fifth Street, 5th Floor         EAGLE-PICHER INDUSTRIES, INC.
Cincinnati, Ohio  45202
Attention:  David Krall                  By /s/ Gary Freytag
                                           ------------------------------------
              Tel. (513) 629-2417           Name:  Gary Freytag
              Fax (513) 629-2572            Title: Treasurer







                                      -12-
<PAGE>   13



<TABLE>
<S>                                     <C>
Address:

One PPG Place, Suite 2950               ABN AMRO BANK N.V., individually and as Agent
Pittsburgh, PA  15222-5401
Attention:  Mr. Gregory D. Amoroso      By /s/ Gregory D. Illegible
                                           -------------------------------------------
               Tel. (412) 566-0983         Name: Gregory D. Illegible
               Fax (412) 566-2266          Title:Senior Vice President

                                         By /s/ Illegible
                                            ------------------------------------------
                                         Name: RIZZI
                                         Title: SVP
</TABLE>




                                      -13-
<PAGE>   14



Address:

201 East Fifth Street, 3rd Floor                  PNC BANK, NATIONAL ASSOCIATION
Cincinnati, OH  45202
Attention:  David F. Knuth/Bruce A. Kintner       By /s/ David F. Knuth
               Tel. (513) 651-8675                  -------------------------
               Fax (513) 651-8952                  Name: David F. Knuth
                                                   Title:  Vice President



                                      -14-
<PAGE>   15




Address:

425 Walnut Street, Mailbox 8160                 FIRSTAR BANK, N.A.
Cincinnati, OH  45202
Attention:  Mr. Derek S. Roudebush              By /s/ Derek Roudelbush
               Tel. (513) 632-4010                -------------------------
               Fax (513) 632-2068                Name:  Derek Roudelbush
                                                 Title:  Vice President





                                      -15-
<PAGE>   16



Address:

277 Park Avenue, 32nd Floor                 ARAB BANKING CORPORATION
New York, NY  10172-3299
Attention:  Ms. Louise Bilbro               By /s/ Louise Bibro
               Tel. (212) 583-4758            -------------------------
               Fax (212) 583-0935            Name: Louise Bibro
                                             Title: Vice President





                                      -16-
<PAGE>   17




Address:

600 Peachtree Street NE, Suite 2700          THE BANK OF NOVA SCOTIA
Atlanta, Georgia  30308
Attention:  Ms. Shannon Dancila              By /s/ F.C.H. Ashby
               Tel. (404) 877-1561             -------------------------
               Fax (404) 888-8998             Name: F.C.H. Ashby
                                              Title: Senior Manager Loan Officer





                                      -17-

<PAGE>   18



Address:
                                             BANK OF TOKYO-MITSUBISHI TRUST
1251 Avenue of the Americas, 12th Floor      COMPANY
New York, NY  10020-1104
Attention:  Mr. Peter Stearn                 By /s/ Peter Stearn
               Tel. (212) 782-4397             -------------------------
               Fax (212) 782-4981             Name: Peter Stearn
                                              Title:  Vice President







                                      -18-

<PAGE>   19



Address:

55 E. Monroe Street, Suite 4700          CREDIT AGRICOLE INDOSUEZ
Chicago, IL  60603
Attention:  Mr. Jerome Leblond           By /s/ Sarah U. Johnson
               Tel. (312) 917-7569         --------------------------------
               Fax (312) 372-9329         Name:  Sarah U. Johnson
                                          Title: Senior Relationship Manager

                                          By /s/ Ernest V. Hodge
                                                 Ernest V. Hodge
                                                 Senior Relationship Manager






                                      -19-
<PAGE>   20


                                           NBD BANK, N.A.
Address:

One Indiana Square, Suite 7034             By /s/ Scott A. Dvornik
Indianapolis, IN  46266                      -------------------------
Attention:  Mr. Ed Hathaway                 Name: Scott A. Dvornik
               Tel. (317) 266-6702
               Fax (317) 266-6042           Title:  Vice President





                                      -20-

<PAGE>   21



Address:
                                          BANK AUSTRIA CREDITANSTALT
Two Greenwich Plaza                        CORPORATE FINANCE, INC.
Greenwich, CT  06830
Attention:  Ms. Maura Connor              By /s/ Maura Connor
               Tel. (203) 861-6432          ----------------------------------
               Fax (203) 861-1475                Maura Connor
                                                 Vice President


                                           By /s/ Catherine K. MacDonald
                                             ----------------------------------
                                                  Catherine K. MacDonald
                                                  Vice President





                                      -21-
<PAGE>   22


Address:

One East 4th Street, 5th Floor        PROVIDENT BANK
Cincinnati, OH  45202
Attention:  Mr. Richard E. Wirthlin   By /s/ Richard E. Wirthlin
               Tel. (513) 579-2022      -------------------------
               Fax (513) 579-2201      Name: Richard E. Wirthlin
                                       Title: Vice President










                                      -22-
<PAGE>   23



Address:

38 Fountain Square Plaza (MD#109054)         FIFTH THIRD BANK
Cincinnati, Ohio  45263
Attention:  Mr. Thomas G. Welch, Jr.         By /s/ Thomas G. Welch, Jr.
               Tel. (513) 744-7757             -------------------------
               Fax (513) 579-5226             Name: Thomas G. Welch, Jr.
                                              Title: AVP




                                      -23-
<PAGE>   24



Address:

One Wall Street, 22nd Floor                  THE BANK OF NEW YORK
New York, NY  10286
Attention:  Mr. Edward J. Dougherty           By /s/ Edward J. Dougherty
               Tel. (212) 635-7842              -------------------------
               Fax (212) 635-6434              Name: Edward J. Dougherty
                                               Title: Vice President
                                                      U.S. Commercial Banking




                                      -24-

<PAGE>   25



Address:

520 Madison Avenue, 37th Floor      COMPAGNIE FINANCIERE DE CIC ET DE
New York, NY  10022                    L'UNION EUROPEENNE
Attention:  Mr. Anthony Rock
               Tel. (212) 715-4422   By /s/ Anthony Rock   /s/ Brian O'Leary
               Fax (212) 715-4535      -----------------------------------
                                      Name: Anthony Rock       Brian O'Leary
                                      Title: Vice Presidents





                                      -25-
<PAGE>   26



Address:

500 Woodward Avenue                          COMERICA BANK
Mail Code 3265
Detroit, MI  48226                           By /s/ Nicholas G. Mester
Attention:  Mr. Nicholas G. Mester             -------------------------
               Tel. (313) 222-9168            Name: Nicholas G. Mester
                                              Title: Account Officer
               Fax (313) 222-3776





                                      -26-
<PAGE>   27



Address:

9920 South LaCienega Blvd., 14th Floor         IMPERIAL BANK
Inglewood, CA  90301
Attention:  Mr. Mark Campbell                  By /s/ Mark Campbell
                Tel. (310) 417-5886              -------------------------
                Fax (310) 417-5997              Name: Mark Campbell
                                                Title: Senior Vice President







                                      -27-

<PAGE>   28



Address:

520 Madison Avenue, 26th Floor              THE MITSUBISHI TRUST AND BANKING
New York, NY  10022                            CORPORATION
Attention:  Mr. Paul Arzouian
              Tel. (212) 891-8425            By /s/ Illegible Mayashi
              Fax (212) 644-6825               -------------------------
                                              Name: Illegible  Mayashi
                                              Title: Senior Vice President






                                      -28-


<PAGE>   29



Address:

111 W. Monroe Street, Fl. 10W               HARRIS TRUST AND SAVINGS BANK
Chicago, IL  60603
Attention: Mr. Peter Krawchuk                By /s/ Peter Krawchuk
              Tel. (312) 461-2783              -------------------------
              Fax (312) 461-5225              Name: Peter Krawchuk
                                              Title: Vice President





                                      -29-


<PAGE>   30



Address:

233 South Wacker Drive                   THE SUMITOMO BANK, LIMITED, CHICAGO
Sears Tower                              BRANCH
Chicago, IL  60606
Attention:  Mr. Dan Casey
              Tel. (312) 879-7672        By /s/
              Fax (312) 876-6436           -------------------------
                                          Name:
                                               ----------------------
                                          Title:
                                                ---------------------

                                      -30-
<PAGE>   31


                                                                    May 18, 1999

                                ANNEX 1 (AMENDED)

                                   COMMITMENT


<TABLE>
<CAPTION>
                                         EXISTING                                                NEW
                      TERM LOAN A        REVOLVER           TOTAL         TERM LOAN A         REVOLVER        TOTAL

<S>                 <C>              <C>              <C>              <C>              <C>              <C>
ABN AMRO Bank N.V   $  6,609,962.49  $ 12,307,692.38  $ 18,917,654.87  $ 13,024,543.05  $ 56,070,514.37  $ 69,095,057.42
   PNC Bank         $  6,609,962.49  $ 12,307,692.31  $ 18,917,654.80  $  3,370,000.00  $  8,630,000.00  $ 12,000,000.00
 Bank of Nova       $  4,693,073.34  $  8,738,461.54  $ 13,431,534.88  $  4,693,073.34  $ 15,306,926.66  $ 20,000,000.00
    Scotia
   Bank of          $  4,693,073.34  $  8,738,461.54  $ 13,431,534.88  $  4,823,436.50  $ 15,176,563.50  $ 20,000,000.00
Tokyo-Mitsubishi
 NBD Bank One       $  9,386,146.68  $ 17,476,923.08  $ 26,863,069.76  $  9,386,146.68  $ 15,353,127.02  $ 24,739,273.70
   Comerica         $  4,693,073.34  $  8,738,461.54  $ 13,431,534.88  $  4,693,073.34  $  8,738,461.54  $ 13,431,534.88
 Credit Agricole    $  6,609,962.43  $ 12,307,692.26  $ 18,917,654.69  $  6,609,962.43  $ 12,307,692.26  $ 18,917,654.69
   Indosuez
Creditanstalt       $  4,693,073.34  $  8,738,461.54  $ 13,431,534.88  $  4,693,073.34  $ 10,306,926.66  $ 15,000,000.00
  Provident         $  4,693,073.34  $  8,738,461.54  $ 13,431,534.88  $  4,693,073.34  $  8,738,461.54  $ 13,431,534.88
 Arab Banking       $  4,957,471.84  $  9,230,769.23  $ 14,188,241.07  $  4,957,471.84  $  9,230,769.23  $ 14,188,241.07
 Corporation
 Bank of New York   $  3,304,981.23  $  6,153,846.15  $  9,458,827.38  $  3,304,981.23  $ 11,153,000.00  $ 14,457,981.23
  CIC Union         $  3,304,981.23  $  6,153,846.15  $  9,458,827.38  $  3,304,981.23  $  6,153,846.15  $  9,458,827.38
 Fifth Third        $  3,304,981.23  $  6,153,846.15  $  9,458,827.38  $  3,304,981.23  $  9,231,000.00  $ 12,535,981.23
     Bank
    Harris          $  3,304,981.23  $  6,153,846.15  $  9,458,827.38  $  3,304,981.23  $ 11,695,018.77  $ 15,000,000.00
   Imperial         $  3,304,981.23  $  6,153,846.15  $  9,458,827.38  $  3,304,981.23  $  6,153,846.15  $  9,458,827.38
  Mitsubishi        $  3,304,981.23  $  6,153,846.15  $  9,458,827.38  $  3,304,981.23  $  6,153,846.15  $  9,458,827.38
    Trust
   Firstar          $  5,155,770.73  $  9,599,999.99  $ 14,755,770.72  $  5,155,770.73  $  9,600,000.00  $ 14,755,770.73
   Sumitomo         $  3,304,981.23  $  6,153,846.15  $  9,458,827.38

                    $ 85,929,511.97  $160,000,000.00  $245,929,511.97  $ 85,929,511.97  $220,000,000.00  $305,929,511.97
</TABLE>




<PAGE>   32








                                    EXHIBIT I

                      JOINDER TO REVOLVING CREDIT AGREEMENT




                                                                     Dated as of

                                                                    ------, ----

ABN AMRO Bank N.V., as
Administrative Agent for
the Lenders party to the
Credit Agreement dated as
of February 19, 1998, as
amended, among
Eagle-Picher Industries,
Inc. (the "Borrower"), the
Lenders party thereto from
time to time, and ABN AMRO
Bank N.V., as
Administrative Agent, PNC
Bank, National
Association, as
Documentation Agent and
NBD Bank, N.A. as
Syndication Agent (the
"Credit Agreement")

Ladies and Gentlemen:

         Reference is made to the Credit Agreement described above. Terms not
defined herein which are defined in the Credit Agreement shall have for the
purposes hereof the meaning provided therein.

         Pursuant to that certain Amendment to Credit Agreement dated as of May
___, 1999, the undersigned hereby joins in the Credit Agreement for the purposes
of becoming a party thereto as one of the "Lenders" and agrees to comply with
all of the terms and conditions of the Credit Agreement. The undersigned agrees
(i) to undertake all of the obligations of a Revolving Lender under the Credit
Agreement and (ii) to provide the Revolving Credit Commitment in the amount set
forth below under the terms and conditions in the Credit Agreement. The
undersigned hereby irrevocably appoints the Administrative Agent to act as
Administrative Agent for the undersigned under the Credit Agreement and the
other Credit Documents, all in accordance with Section 11 of the Credit
Agreement and the other provisions of the Credit Agreement and the other Credit
Documents.



<PAGE>   33




         IN WITNESS WHEREOF, the undersigned has executed this Joinder as of the
date first above written.


                                       ---------------------------------------,
                                       as Lender



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

                                       Revolving Credit
                                       Commitment Amount:  $
                                                            --------------------



                                        Address for Notices:

                                          --------------------------------------
                                          --------------------------------------
                                          --------------------------------------
                                          Attention:
                                                    ----------------------------
                                          Telephone:
                                                    ----------------------------
                                          Telecopier:
                                                     --------------------------