Exhibit
10.4




Joinder
Agreement






SUPPLEMENT
NO. 1 dated as of May 5, 2008, to the Guarantee Agreement, dated as of
February 28, 2008 (as amended, restated, amended and restated, supplemented or
otherwise modified from time to time, the “Guarantee
Agreement”), among each of the subsidiaries of SOLUTIA INC., a
Delaware corporation (the “Borrower”) listed on
Schedule I
thereto (each such subsidiary individually, a “Subsidiary Guarantor”
and collectively, together with each other Subsidiary that becomes a party
thereto, the “Subsidiary
Guarantors”) in favor of CITIBANK, N.A., as collateral agent (in such
capacity, together with its successors in such capacity, the “Collateral Agent”) on
behalf of the Secured Parties (as defined in the Credit Agreement referred to
below).






A.  Reference
is made to the Credit Agreement dated as of February 28, 2008 (as amended,
restated, amended and restated, supplemented or otherwise modified from time to
time, the “Credit
Agreement”), among the Borrower, the Collateral Agent, Citibank, N.A., as
administrative agent (in such capacity and together with any successors in such
capacity, the “Administrative
Agent”) for the Lenders (as defined herein), the lending institutions
from time to time party thereto (the “Lenders”), and the
other agents party thereto.  Capitalized terms used herein and not
otherwise defined herein shall have the meanings assigned to such terms in the
Guarantee Agreement.






B.  The
Guarantors have entered into the Guarantee Agreement in order to induce the
Lenders to enter into the Credit Agreement and to induce the Lenders to make
Loans to the Borrower under the Credit Agreement.






C.  Pursuant
to Section 5.15 of the Credit Agreement and Section 19 of the Guarantee
Agreement, each Subsidiary (other than any Excluded Subsidiary) of the Borrower
that was not in existence or not a Subsidiary on the date of the Credit
Agreement is required to enter into the Guarantee Agreement upon becoming a
Subsidiary.  Each undersigned Subsidiary (“New Subsidiary”) is
executing this Supplement in accordance with the requirements of the Credit
Agreement and Guarantee Agreement to become a Guarantor under the Guarantee
Agreement.






Accordingly,
the Collateral Agent and each New Subsidiary agree as follows:






1)  In
accordance with Section 19 of the Guarantee Agreement, each New Subsidiary by
its signature below becomes a Guarantor under the Guarantee Agreement with the
same force and effect as if originally named therein as a Guarantor and each New
Subsidiary hereby (a) agrees to all the terms and provisions of the Guarantee
Agreement applicable to it as a Guarantor thereunder and (b) represents and
warrants that the representations and warranties made by it as a Guarantor
thereunder are true and correct (or true and correct in all material respects if
not otherwise qualified by materiality or a Material Adverse Effect) on and as
of the date hereof (except to the extent that they expressly relate to an
earlier date, in which case they shall be true and correct (or true and correct
in all material respects if not otherwise qualified by materiality or a Material
Adverse Effect) as of such earlier date).  As of the date hereof, each
reference to a Guarantor in the Guarantee Agreement shall be deemed to include
each New Subsidiary.  The Guarantee Agreement is hereby incorporated
herein by reference.









SECTION
1. Each New
Subsidiary represents and warrants to the Collateral Agent and the other Secured
Parties that this Supplement has been duly authorized, executed and delivered by
it and constitutes its legal, valid and binding obligation, enforceable against
it in accordance with its terms, except that the enforcement thereof may be
subject to bankruptcy, insolvency, reorganization, moratorium or other similar
laws now or hereafter in effect relating to creditors’ rights generally and to
general principles of equity, regardless of whether considered in a proceeding
in equity or at law.






SECTION
2. This
Supplement may be executed in counterparts (and by different parties hereto on
different counterparts), each of which shall constitute an original, but all of
which when taken together shall constitute a single
contract.  Delivery of an executed signature page to this Supplement
by facsimile or other electronic transmission shall be as effective as delivery
of a manually signed counterpart of this Supplement.






SECTION
3. Except as
expressly supplemented hereby, the Guarantee Agreement shall remain in full
force and effect.






SECTION
4. THIS
SUPPLEMENT SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF
THE STATE OF NEW YORK.






SECTION
5. In case
any one or more of the provisions contained in this Supplement should be held
invalid, illegal or unenforceable in any respect, the validity, legality and
enforceability of the remaining provisions contained herein and in the Guarantee
Agreement shall not in any way be affected or impaired thereby (it being
understood that the invalidity a particular provision in a particular
jurisdiction shall not in and of itself affect the validity of such provision in
any other jurisdiction).  The parties hereto shall endeavor in
good-faith negotiations to replace the invalid, illegal or unenforceable
provisions with valid provisions the economic effect of which comes as close as
possible to that of the invalid, illegal or unenforceable
provisions.






SECTION
6. All
communications and notices hereunder shall (except as otherwise expressly
permitted herein) be in writing and given as provided in Section 9.01 of
the Credit Agreement.  All communications and notices hereunder to any
New Subsidiary shall be given to it c/o the Borrower at the Borrower’s address
as provided in Section 9.01 of the Credit Agreement, with a copy to the
Borrower.






SECTION
7.  E ach New
Subsidiary agrees to reimburse the Collateral Agent for its reasonable
out-of-pocket expenses in connection with this Supplement, including the
reasonable fees, other charges and disbursements of counsel for the Collateral
Agent in each case in accordance with the terms of the Credit
Agreement.




[Signature
Page Follows]












IN
WITNESS WHEREOF, each New Subsidiary and the Collateral Agent have duly executed
this Supplement as of the day and year first above written.





S E
      Investment LLCBy:
            /s/ James A.
      TichenorName:
            James
      A. TichenorTitle:
            Vice
      President and TreasurerAddress:
            575
      Maryville Centre Drive
              St.
      Louis, MO 63141CITIBANK,
      N.A.
              As
      Collateral AgentBy:
            /s/ David
      JaffeName:
            David
      JaffeTitle:
            Director/Vice
      President