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                                   THIRD AMENDMENT
                                         OF
                            McWHORTER TECHNOLOGIES, INC.
                      EMPLOYEE STOCK OWNERSHIP PLAN AND TRUST
                      (As Adopted Effective February 18, 1994)


          WHEREAS, McWhorter Technologies, Inc. (the "Company") maintains
McWhorter Technologies, Inc. Employee Stock Ownership Plan and Trust (the
"Plan"); and

          WHEREAS, amendment of the Plan is now considered desirable;

          NOW, THEREFORE, the Company, acting in accordance with Section 17.1 of
the Plan, hereby amends the Plan, effective July 1, 1998, as follows:

          1.   By adding the following at the end of Paragraph 2.1(15) of the
Plan:

     "Only an Affiliate of the Company may become an Employer."

          2.   By adding the following new Paragraph 2.1(39) to the Plan:

          "(39) "Company" shall mean McWhorter
                Technologies, Inc. or its successor."

          3.   By substituting the following for Subsection 6.4(b) of the Plan:

          "(b) In the exercise of voting rights, Employer
               Securities held in the suspense accounts
               described in Sections 5.7 or 6.2 and
               allocated shares of Employer Securities

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               held for the benefit of Participants who do
               not give timely voting instructions shall
               be voted by the Trustee as instructed by
               the Committee."

          4.   By substituting the following sentence for the last sentence of
Section 12.1 of the Plan:

     "Except to the extent such duties may be expressly
     allocated to the Trustee by the terms of this Plan
     and Trust, the Trustee in its capacity as such shall
     have no authority or responsibility with respect to
     the operation and administration of the Plan."

          5.   By adding the following sentence at the end of Section 12.7 of
the Plan:

     "Upon the expiration of ninety (90) days from the
     date of filing such account, the Trustee shall be
     forever released and discharged from all liability
     and accountability to the Administrative Committee
     with respect to the accuracy of such accounting and
     the propriety of all acts and failures to act of the
     Trustee reflected in such account for which it shall
     be responsible hereunder, except with respect to any
     such acts or transactions as to which the
     Administrative Committee shall within such 90 day
     period file with the Trustee specific written
     objections."

          6.   By inserting the wording "gross" immediately prior to the 
word "negligence" where the latter appears in the first sentence of Section 
12.10 of the Plan.

          7.   By substituting the following for the second sentence of Section
12.10 of the Plan:

     "The Employer shall indemnify the Trustee for any
     loss, damage or liability which the Trustee may incur
     or sustain arising out of any direction given to it
     by the Employer, the Committee or an investment
     advisor in accordance with the Plan."


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          8.   By adding the following at the end of Paragraph 16.1:

     "Only an Affiliate of the Company may become a
     Participant Employer."

          9.   By substituting "Company" for "Employer" when the latter 
appears in Section 11.1, 13.1 and 13.2."

          IN WITNESS WHEREOF, the Company, acting through its duly authorized
representative, hereby adopts the foregoing this 2nd day of June, 1998.


                              McWHORTER TECHNOLOGIES, INC.



                              By /s/ Mia F. Igyarto
                                -------------------------------------
                                Its VP, Human Resources & Quality





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