<PAGE>

                                                                    EXHIBIT 10.3

================================================================================

                                     FORM OF

                          TAX DISAFFILIATION AGREEMENT,

                      dated as of May_ , 2000, by and among

                        GREAT LAKES CHEMICAL CORPORATION

                                       and

                                   OSCA, INC.



================================================================================
<PAGE>

<TABLE>
<CAPTION>

                                                   TABLE OF CONTENTS


<S>                                                                                                                  <C>
ARTICLE I ............................................................................................................1
          DEFINITIONS.................................................................................................1
                   Class A Common Stock...............................................................................2
                   Code     ..........................................................................................2
                   GLC      ..........................................................................................2
                   GLC Group..........................................................................................2
                   Consolidated Tax Period............................................................................2
                   Final Determination................................................................................2
                   Income Tax Return..................................................................................2
                   Income Tax.........................................................................................2
                   IPO Date ..........................................................................................2
                   OSCA Group.........................................................................................3
                   OSCA Group Combined Tax Liability..................................................................3
                   OSCA Group Tax Liability...........................................................................3
                   Proceeding.........................................................................................3
                   Regulations........................................................................................3
          Restructuring Transactions..................................................................................3
          Restructuring Tax...........................................................................................3
                   Separate Return Tax Period.........................................................................3
                   Tax      ..........................................................................................3
                   Taxes    ..........................................................................................3
                   Tax Return.........................................................................................4

ARTICLE II............................................................................................................4
          TAX RETURNS, TAX PAYMENTS AND EVENT OF LOSS.................................................................4
                   2.1      Obligation to Prepare and File Tax Returns................................................4
                   2.2      Payment of Taxes to Taxing Authorities....................................................5
                   2.3      Allocation of Taxes.......................................................................5
                   2.4      Recomputation and Adjustment of Taxes.....................................................6
                   2.5      Indemnification...........................................................................6
                   2.6      Payment of Taxes for Separate Return Tax Periods..........................................7
                   2.7      Interest..................................................................................7

ARTICLE III...........................................................................................................7
          CARRYFORWARD TAX ATTRIBUTES.................................................................................7
                   3.1.     Separate Return Tax Period Carryforward Tax Attributes....................................7
                   3.2.     Calculation of Carryforward Tax Attributes................................................8
                   3.3.     Tax Attributes to be Claimed for Separate Return Tax Periods..............................8
                   3.4.     Carryback Items from Separate Return Tax Periods..........................................8

</TABLE>



                                                           i
<PAGE>

<TABLE>
<CAPTION>
<S>                                                                                                                  <C>

ARTICLE IV............................................................................................................9
          TAX AUDITS..................................................................................................9
                   4.l      General...................................................................................9
                   4.2      Notice of Proceeding......................................................................9

ARTICLE V ...........................................................................................................10
          COOPERATION; RECORD RETENTION; ACCESS; CONFIDENTIALITY.....................................................10
                   5.1      Cooperation..............................................................................10
                   5.2      Record Retention; Access.................................................................10
                   5.3      Information Confidential.................................................................11

ARTICLE VI...........................................................................................................11
          DISPUTE RESOLUTION.........................................................................................11
                   6.1      Intent of Parties........................................................................11
                   6.2      Dispute Resolution.......................................................................11

ARTICLE VII..........................................................................................................12
          MISCELLANEOUS PROVISIONS...................................................................................12
                   7.1      Termination..............................................................................12
                   7.2      Notices..................................................................................12
                   7.3      Governing Law............................................................................13
                   7.4      Change in Law............................................................................13
                   7.5      Treatment of Payments....................................................................13
                   7.6      Binding Effect; No Assignment; Third Party Beneficiaries.................................13
                   7.7      Entire Agreement; Amendments.............................................................13
                   7.8      Counterparts.............................................................................13
                   7.9      Interpretation; Descriptive Headings.....................................................14
                   7.10     Successors and Assigns...................................................................14
</TABLE>




                                                          ii
<PAGE>

                                     FORM OF
                          TAX DISAFFILIATION AGREEMENT

         TAX DISAFFILIATION AGREEMENT (the "Agreement") dated as of May __, 2000
by and between Great Lakes Chemical Corporation, a Delaware corporation ("GLC"),
and OSCA, Inc., a Delaware corporation and a direct, wholly-owned subsidiary of
GLC ("OSCA").

                                    RECITALS

         WHEREAS, GLC is the common parent of an affiliated group of
corporations within the meaning of Section 1504(a) of the Internal Revenue Code
of 1986, as amended (the "Code"), and OSCA is a member of such group.

         WHEREAS, the members of such affiliated group have heretofore joined in
filing consolidated federal Income Tax Returns.

         WHEREAS, the board of directors of GLC has determined that it is in the
best interests of GLC and its stockholders to offer shares of Class A Common
Stock, par value $0.01 per share (the "Class A Common Stock") of OSCA for sale
to the public pursuant to an initial public offering ("IPO").

         WHEREAS, GLC and OSCA desire on behalf of themselves and their
successors to set forth their rights and obligations with respect to Taxes due
for periods before and after the IPO.

         NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto agree as
follows:

                                    ARTICLE I

                                   DEFINITIONS

         1.1 For the purposes of this Agreement, the following terms have the
following meanings:

         "Business Day" means any day other than a Saturday, a Sunday, or a day
on which banking institutions located in the State of Indiana are authorized or
obligated by law or executive order to close.

         "Carryforward Tax Attribute" means a deductible or creditable
consolidated United States federal tax attribute, including, but not limited to,
(i) a consolidated net operating loss, a consolidated net capital loss, a

                                        1
<PAGE>

consolidated unused investment credit, a consolidated unused foreign tax credit,
or a consolidated excess charitable contribution (see Section 1.1502-79 of the
Regulations), and (ii) the consolidated minimum tax credit, credit for producing
fuel from a nonconventional source, low-income housing credit or other
consolidated general business credits, that can be carried forward from one tax
period to subsequent tax periods.

         "Class A Common Stock" shall have the meaning set forth in the above
recitals.

         "Code" shall have the meaning set forth in the above recitals.

         "GLC" shall have the meaning set forth in the above preamble.

         "GLC Group" means GLC and all corporations which from time to time join
with GLC in filing a consolidated federal Income Tax Return with GLC as the
common parent of that group.

         "Consolidated Tax Period" means (i) any tax period of the GLC Group
ending before, with, or which includes the IPO Date during which any member of
the OSCA Group was a member of the GLC Group and (ii) any tax period ending
after the IPO Date in which the GLC Group and the OSCA Group are required to
file a consolidated or combined state or local Tax Return (any such period
described in this clause (ii) shall be a Consolidated Tax Period only for
purposes of such Tax Return).

         "Final Determination" shall mean with respect to any issue (1) a
decision, judgment, decree or other order by any court of competent
jurisdiction, which decision, judgment, decree or other order has become final
and not subject to further appeal, (2) a closing agreement entered into under
Section 7121 the Code or any other binding settlement agreement (whether or not
with the Internal Revenue Service) entered into in connection with or in
contemplation of an administrative judicial proceeding, or (3) the completion of
the highest level of administrative proceedings if a judicial contest is not or
is no longer available.

         "Income Tax Return" means any return, report, filing, statement,
declaration or other document required to be filed with a taxing authority in
respect of Income Taxes.

         "Income Tax" means any United States federal, state, local or foreign
tax, charge, fee, levy or other assessment which is determined with reference to
(i) net income or profits (including, but not limited to, capital gains, gross
receipts, value added or minimum tax, but not including sales or use tax), or
(ii) multiple bases, including but not limited to, corporate franchise, gross
receipts, net worth, privilege, doing business or occupation taxes, if one of
the bases is listed in clause (i).

         "IPO Date" means the last date that OSCA is included in the GLC Group's
consolidated federal Income Tax Return.


                                        2
<PAGE>

         "OSCA" shall have the meaning set forth in the preamble.

         "OSCA Group" means OSCA and all corporations which from time to time
would join with OSCA in filing a consolidated federal Income Tax Return with
OSCA as the common parent of that group if OSCA were not a member of the GLC
Group. The term "OSCA Group" shall be deemed to include any direct or indirect
foreign subsidiaries of OSCA as if each such foreign subsidiary were an
"includable corporation" for purposes of section 1504 of the Code.

         "OSCA Group Combined Tax Liability" means the OSCA Group's liability
for Taxes as determined under Section 2.3(c) of this Agreement.

         "OSCA Group Tax Liability" means the OSCA Group consolidated federal
Income Tax liability, determined as of the end of the applicable tax period in
accordance with Section 1.1502-1, et seq. of the Regulations as if (i) the
highest rate of tax specified in Section 11(b) of the Code were the only rate
set forth in that subsection, and (ii) the OSCA Group were a separate affiliated
group of corporations filing a consolidated federal Income Tax Return, including
any elections which have been made by OSCA pursuant to the Code or the
Regulations.

         "Proceeding" means any audit or other examination, protest, appeals or
other administrative or judicial proceeding relating to liability for or refunds
or adjustments with respect to Taxes for any tax period.

         "Regulations" means the regulations promulgated under the Code, in
effect from time to time.

         "Restructuring Transactions" means the transactions undertaken in
connection with the IPO to restructure or separate those companies or entities
that will be owned directly or indirectly by OSCA on or after the IPO Date, on
the one hand, and those companies or entities that will be owned directly or
indirectly by GLC, on the other hand.

         "Restructuring Tax" means any registration, transfer or income taxes
(net of any current Tax benefits received in connection therewith) directly
resulting from the Restructuring Transactions imposed upon OSCA or any member of
the OSCA Group; provided that, such term shall not refer to the collateral Tax
effects of the Restructuring Transactions (including, without limitation,
relating to the tax basis of assets).

         "Separate Return Tax Period" means any tax period of OSCA or any member
of the OSCA Group which is not included in a Consolidated Tax Period, or any tax
period of the GLC Group subsequent to the final Consolidated Tax Period.

                                        3
<PAGE>

         "Tax" or "Taxes" means all taxes, charges, fees, levies, imposts,
duties and other assessments, including, without limitations, income, gross
receipts, excise, personal property, real property, sales, ad valorem,
value-added, withholding, social security, occupation, use, service, service
use, leasing, leasing use, license, payroll, franchise, transfer and recording
taxes, fees and charges, imposed by the United States or any state, local, or
foreign governmental authority whether computed on a separate, consolidated,
unitary, combined or any other basis; and such term shall include (including
without limitation any duty to reimburse another party for indemnified Taxes or
refunds or credit of Taxes) any interest, fines, penalties and additional
amounts attributable to, imposed on, or with respect to, any such taxes,
charges, fees, levies, imposts, duties or other assessments, and interest
thereon.

         "Tax Return" shall mean any return, information return, form, report,
filing, statement, declaration or other document required to be filed with a
taxing authority in respect of any Tax or Taxes.

                                   ARTICLE II

                   TAX RETURNS, TAX PAYMENTS AND EVENT OF LOSS

         2.1 Obligation to Prepare and File Tax Returns.

         (a) Consolidated or Combined Tax Returns

             (i) GLC's Obligation to Prepare and File Tax Returns. GLC will
prepare and file the GLC Group's consolidated federal Income Tax Returns and its
consolidated or combined state or local Tax Returns for the Consolidated Tax
Periods (including the Consolidated Tax Period that includes the IPO Date). GLC
shall have the exclusive right, in its sole discretion, with respect to any Tax
Return described in this Section 2.1(a) to determine (1) the manner in which
such Tax Return shall be prepared and filed, including the elections, methods of
accounting, positions, conventions and principles of taxation to be used and the
manner in which any item of income, gain, loss, deduction, credit or other
attribute (a "Tax Item") shall be reported, (2) whether any extensions may be
requested, (3) the elections that will be made by GLC and any member of the GLC
Group, OSCA and any member of the OSCA Group on such Tax Return, (4) whether any
amended Tax Returns shall be filed, (5) whether any claims for refund shall be
made, (6) whether any refunds shall be paid by way of refund or credited against
liability for the related Tax, and (7) whether to retain outside firms to
prepare or review such Tax Return.

              (ii) OSCA's Obligation to Prepare or File Tax Returns. For each
Consolidated Tax Period, OSCA shall provide GLC with documents and other
information consistent with past practice, including but not limited to,
workpapers and schedules, state apportionment schedules, fixed asset ledgers,
detailed general ledgers, schedule M analysis and

                                        4
<PAGE>

journal entries, in order for GLC to prepare the federal Income Tax Return and
state and local Tax Returns for each jurisdiction in which OSCA is included in a
consolidated or combined state or local Tax Return with any member of the GLC
Group, in each case, on or before the date which is 15 days prior to the due
date of such Tax Return. Items of income, gain, deduction, loss and credit to be
included in any Income Tax Returns for the Consolidated Tax Period that includes
the IPO Date shall be determined by the method described in Section 2.1(a)(iii).

              (iii) OSCA's Final Consolidated Tax Period. Notwithstanding
anything in this Agreement to the contrary, the OSCA Group Tax Liability for the
Consolidated Tax Period that OSCA ceases to be a member of the GLC Group shall
be determined pursuant to Reg. Section 1.1502-76 by including only that portion
of the taxable year ending on the IPO Date, based on a closing of the books for
income tax purposes and, immediately before the IPO, items of income, gain,
loss, deduction, and credit will be taken into account (to the extent not
previously taken into account in the computation of the OSCA Group Tax
Liability) as required by the applicable intercompany transaction Regulations.

         (b) OSCA Separate Returns.

              (i) Separate State, Local and Foreign Returns. OSCA shall prepare
and timely file Tax Returns, and pay its separate Tax liabilities or estimated
separate Tax liabilities for any tax jurisdiction in which OSCA (or any member
of the OSCA Group) is required to file (or does file) a separate state, local or
foreign Tax Return directly with the taxing authority and not as a part of a GLC
return for a period that includes a Consolidated Tax Period.

              (ii) Separate Return Tax Periods. GLC and OSCA shall each prepare
and timely file Tax Returns, and pay their own Tax liabilities directly with the
taxing authorities for all Separate Return Tax Periods.

              (iii) Separate Tax Return Adjustments. If there are any
adjustments to the Tax liabilities of the OSCA Group for Separate Return Tax
Periods or for separate state or local Tax Returns for a Consolidated Tax
Period, OSCA will control the conduct of Proceedings related thereto, and will
pay the Tax liability, if any, directly to the relevant taxing authority.

         2.2 Payment of Taxes to Taxing Authorities.

         (a) Federal Income Taxes for Consolidated Tax Periods. GLC shall pay
(or cause to be paid) all federal Income Taxes with respect to the GLC Group's
federal Income Tax Return and its consolidated or combined state or local Tax
Returns for the Consolidated Tax Periods.

         (b) Separate State, Local and Foreign Taxes. OSCA shall pay (or cause
to be paid) to the appropriate tax authorities all Taxes with respect to any
separate state, local or foreign Tax Return filed or required to be filed by
OSCA or any member of the OSCA Group.


                                        5
<PAGE>

         2.3 Allocation of Taxes.

         (a) OSCA Liability For Taxes. For each Consolidated Tax Period, OSCA
shall be liable for and shall pay to GLC an amount equal to the sum of the OSCA
Group Tax Liability and the OSCA Group Combined Tax Liability for such taxable
period.

         (b) OSCA Group Tax Liability. With respect to each Consolidated Tax
Period (including the Consolidated Tax Period that includes the IPO Date), the
OSCA Group Tax Liability for such taxable period shall be the OSCA Group's
liability for federal Income Taxes for such taxable period, as determined in
accordance with Section 2.1(a)(iii).

         (c) OSCA Group Combined Tax Liability. With respect to any Consolidated
Tax Period (including the Consolidated Tax Period that includes the IPO Date and
any tax period described in clause (ii) of the definition of Consolidated Tax
Period), the OSCA Group Combined Tax Liability shall be the sum for such taxable
period of the OSCA Group's liability for each consolidated or combined state or
local Tax Return, as determined in a manner consistent with the principles and
procedures set forth in Section 2.1(a)(iii).

         2.4 Recomputation and Adjustment of Taxes; Amended Returns. For any
Consolidated Tax Period, in the event of a redetermination of any Tax Item of
any member of the GLC Group or OSCA Group as a result of a Final Determination,
the filing of a Tax refund claim or the filing of an amended Tax Return pursuant
to which Taxes are paid to a tax authority or a refund of Taxes is received from
a tax authority, GLC and OSCA shall prepare jointly, in accordance with the
principles and procedures set forth in this Agreement, revised Tax Returns, as
appropriate, to reflect the redetermination of such Tax Item as a result of such
Final Determination, filing of a Tax refund claim or filing of an amended Tax
Return. Following the preparation of such revised Tax Returns, OSCA's payment
obligations under Sections 2.3 hereof shall be redetermined. Without the prior
written consent of GLC (which consent may be withheld in its sole discretion),
OSCA (and each member of the OSCA Group) shall not amend any Tax Return,
including, but not limited to, any foreign Tax Returns, for any Consolidated Tax
Period.

         2.5 Indemnification.

         (a) Failure to Pay. GLC and each member of the GLC Group shall jointly
and severally indemnify OSCA and each member of the OSCA Group and their
respective directors, officers and employees, and hold them harmless from and
against any Tax or Loss that is attributable to, or results from the failure of
GLC to make any payment required to be made under this Agreement. OSCA and each
member of the OSCA Group shall jointly and severally indemnify GLC and each
member of the GLC Group and their respective directors, officers and employees,
and hold them harmless from and against any Tax or Loss that is attributable to,
or results from, the failure


                                        6
<PAGE>

of OSCA or any member of the OSCA Group to make any payment required to be made
under this Agreement.

         (b) Inaccurate or Incomplete Information. GLC and each member of the
GLC Group shall jointly and severally indemnify OSCA, each member of the OSCA
Group and their respective directors, officers and employees, and hold them
harmless from and against any Tax or Loss attributable to the negligence of GLC
or any GLC Affiliate in supplying OSCA or any member of the OSCA Group with
inaccurate or incomplete information, in connection with the preparation of any
Tax Return or the conduct of any Proceeding. OSCA and each member of the OSCA
Group shall jointly and severally indemnify GLC, each member of the GLC Group
and their respective directors, officers and employees, and hold them harmless
from and against any Tax or Loss attributable to the negligence of OSCA or any
member of the OSCA Group in supplying GLC or any member of the GLC Group with
inaccurate or incomplete information, in connection with the preparation of any
Tax Return or the conduct of any Proceeding.

         (c) IPO Restructuring Taxes. GLC and each member of the GLC Group shall
jointly and severally indemnify OSCA and each member of the OSCA Group, and hold
them harmless from and against any Restructuring Taxes incurred by any member of
the OSCA Group as a direct result of the Restructuring Transactions.

         2.6 Payment of Taxes for Separate Return Tax Periods. Except as
otherwise provided in this Agreement, GLC shall pay or cause to be paid all
Taxes and shall be entitled to receive and retain all refunds of Taxes with
respect to Tax Returns relating to Separate Return Tax Periods for which GLC has
filing responsibility, including under this Agreement. Except as otherwise
provided in this Agreement, OSCA shall pay or cause to be paid all Taxes and
shall be entitled to receive and retain all refunds of Taxes with respect to Tax
Returns relating to Separate Return Tax Periods for which OSCA has filing
responsibility, including under this Agreement.

         2.7 Interest. Payments pursuant to this Agreement that are not made
within the period prescribed in this Agreement or, if no period is prescribed,
within fifteen (15) business days after demand for payment is made (the "Payment
Period") shall bear interest for the period from and including the date
immediately following the last date of the Payment Period through and including
the date of payment (the "Interest Accrual Period") at a per annum rate equal to
the long-term applicable federal rate ("AFR") in effect on the last day of such
Payment Period, plus 200 basis points. Such interest will be payable at the same
time as the payment to which it relates and shall be calculated on the basis of
a year of 365 days and the actual number of days for which due.

                                        7
<PAGE>

                                   ARTICLE III

                           CARRYFORWARD TAX ATTRIBUTES

         3.1. Separate Return Tax Period Carryforward Tax Attributes. The
Carryforward Tax Attributes available to the OSCA Group for Separate Return Tax
Periods will be determined by allocating the Carryforward Tax Attributes of the
GLC Group available to carry forward to tax periods beginning after the end of
the final Consolidated Tax Period among the GLC Group and the OSCA Group, as
described below:

         (a) Federal Tax Attributes. Unless the final or temporary Regulations
expressly require an allocation of particular items of the GLC Group's
Carryforward Tax Attributes from the final Consolidated Tax Period to the OSCA
Group's Separate Return Tax Periods, no Carryforward Tax Attributes will be
allocated to OSCA. GLC will allocate to the OSCA Group only that portion, if
any, of particular Carryforward Tax Attribute items as the final or temporary
Regulations expressly require to be so allocated. The portion, if any, of any
the GLC Group consolidated unused foreign tax credit which is allocable to OSCA
shall be determined separately with respect to each of the items of income
listed in Section 904(d) of the Code.

         (b) State, Local or Foreign Tax Attributes. No tax attributes arising
from state or local Tax Returns shall be allocated to OSCA or any member of the
OSCA Group, unless under the provisions of applicable state law or state
regulations such tax attributes are expressly required to be allocated to OSCA.

         3.2. Calculation of Carryforward Tax Attributes. Calculation of the
portion of any Carryforward Tax Attribute and state, local or foreign tax
attributes available to OSCA or to any member of the OSCA Group shall be made by
GLC in accordance with this Article III. Such calculation will be provided to
OSCA as soon as practicable but in any case estimates shall be provided to OSCA
not later than a date that permits OSCA sufficient time to prepare and to timely
file its Tax Returns for the OSCA Group=s first Separate Return Tax Period,
taking all extensions of time to file Tax Returns into consideration. GLC shall
also advise OSCA of any adjustments to such calculations as a result of a tax
audit, a Final Determination, or otherwise. OSCA shall have a right to review
GLC=s calculations made pursuant to this Section 3.2.

         3.3. Tax Attributes to be Claimed for Separate Return Tax Periods. OSCA
shall prepare and file all of its Tax Returns for all Separate Return Tax
Periods taking into account the amount of the Carryforward Tax Attributes
provided to OSCA by GLC pursuant to this Article III, or such tax attributes as
finally determined.

         3.4. Carryback Items from Separate Return Tax Periods. With respect to
carrybacks by OSCA of net operating losses, net capital losses, unused tax
credits and other deductible or creditable tax attributes to a Consolidated Tax
Period from a Separate Return Tax Period which would be permitted under the Code
and the Regulations (or state law or state regulations), taking into
consideration the separate return limitation year rules, whenever permitted to
do so by the Code, the Regulations, state law or state regulations, OSCA shall
elect to relinquish any carryback period which would include any Consolidated
Tax Period. In cases where OSCA


                                        8
<PAGE>

cannot relinquish the carryback period, or if the parties otherwise agree, GLC
shall cooperate with OSCA in seeking tax refunds from the appropriate taxing
authority, at OSCA=s expense, and OSCA shall be entitled to such refund,
including interest paid by the taxing authority in connection with such refund;
provided, however, that OSCA shall indemnify and hold GLC harmless from and
against any and all collateral tax consequences resulting from or caused by the
carryback of deductible or creditable tax attributes by OSCA from a Separate
Return Tax Period to a Consolidated Tax Period, including, but not limited to,
tax attributes of GLC that expire unused (including tax attributes that expire
during a tax period subsequent to the tax period during which the OSCA tax
attribute carried back was generated) and which would have been used but for
OSCA=s carryback. The amount of such indemnity shall be limited to the actual
tax benefit to which the GLC Group would have been entitled in the absence of
the carryback of the deductible or creditable tax attribute of OSCA. GLC shall
only be entitled to indemnification under this Section 3.4 if GLC has used
reasonable efforts to avoid the collateral tax consequence being indemnified.
OSCA shall have the right to review the collateral tax consequence being
indemnified. The amount of the refund due to OSCA from GLC shall be reduced by
the amount of the indemnification, if any.

         In the event that (i) OSCA or a member of the OSCA Group has filed a
refund claim with a taxing authority for a Consolidated Tax Period as
contemplated by this Section 3.4, (ii) the refund claim has been allowed, and
(iii) the taxing authority has applied the refund to an amount owed by GLC, then
GLC shall pay OSCA the amount of the refund, including the amount of interest
that would otherwise have been paid by the taxing authority to OSCA or such
member of the OSCA Group. The refund payment shall be due to OSCA within ten
Business Days after the earlier of (i) the date that GLC receives the refund
from the taxing authority, or (ii) the date that GLC receives notice from the
applicable taxing authority that it has applied the refund to an amount owed by
GLC.

                                   ARTICLE IV

                                   TAX AUDITS

         4.l General. GLC shall have the sole right to represent the interests
of the GLC Group, including all members of the OSCA Group, in any Proceeding in
connection with any Tax liability for a Consolidated Tax Period for which a
member of the GLC Group may be liable. GLC's rights shall extend to any matter
pertaining to the management and control of a Proceeding, including, without
limitation, execution of waivers, choice of forum, scheduling of conferences and
the resolution of any Tax Item. Notwithstanding the foregoing, if such
Proceeding relates to Taxes as to which the OSCA Group is solely liable for the
payment of such Taxes under this Agreement or otherwise and would not result in
any additional Tax liability or detriment to the GLC Group, OSCA shall have the
right to represent the interests of OSCA, including all members of the OSCA
Group, in such Proceeding so long as (x) OSCA shall have agreed in writing to
pay all costs and expenses that it shall incur in connection with contesting
such proposed adjustment, including, without limitation, all attorneys',
accountants' and investigatory fees and disbursements and (y)


                                        9
<PAGE>

OSCA shall have acknowledged in writing its obligation to pay the Taxes and/or
indemnify the GLC Group against all costs and expenses with respect to such
Proceeding; provided, however, if such Proceeding would result in the extension
of the statute of limitations with respect to any Tax Return for which any
member of the GLC Group may be liable, GLC may, in its sole discretion, on at
least 10 Business Days notice to OSCA, require OSCA to pay the Tax proposed and
sue for a refund or to take any other action GLC may reasonably request to
prevent such an extension.

         4.2 Notice of Proceeding. GLC will notify OSCA in writing of any
pending or threatened Proceeding in connection with any Income Tax liability for
which any member of the OSCA Group may be liable, promptly upon receipt of
notice of such Proceeding by any member of the GLC Group. OSCA will notify GLC
in writing of any pending or threatened Proceeding in connection with any Income
Tax liability for which any member of the GLC Group may be liable, promptly upon
receipt of notice of such Proceeding by any member of the OSCA Group.
Notification must include a complete copy of any written communication, and a
complete written summary of any oral communication. The failure of GLC or OSCA
to timely forward such notification shall not relieve the other party of its
obligation to pay such Income Tax, except to the extent that the failure to
timely forward notification prejudices the ability of the other party to contest
the Income Tax liability.

                                    ARTICLE V

             COOPERATION; RECORD RETENTION; ACCESS; CONFIDENTIALITY

         5.1 Cooperation. GLC (and each member of the GLC Group) and OSCA (and
each member of the OSCA Group) will provide each other with the cooperation and
information reasonably requested by the other party in connection with tax
planning, the preparation or filing of any Tax Return (or claim for refund), the
determination and payment of estimated Tax, or the conduct of any Proceeding;
provided, however, that neither party is required to disclose privileged and
confidential information. Such cooperation and information includes: (i)
promptly forwarding copies of appropriate notices and other communications
(including, information document requests, revenue agent's reports and similar
reports, notices of proposed adjustments and notices of deficiency) received
from or sent to any taxing authority, (ii) providing copies of all relevant Tax
Returns (including workpapers and schedules), and documents relating to rulings
or other determinations by taxing authorities, (iii) providing copies of records
concerning the ownership and tax basis of property, (iv) providing other
relevant information which either party may possess, including explanations of
documents and information provided under this Agreement, as well as access to
appropriate personnel, (v) the execution of any document that may be necessary
or reasonably helpful in connection with the filing of an Tax Return (or claim
for refund) or in connection with any Proceeding, including waivers, consents or
powers of attorney, and (vi) the use of the parties' reasonable efforts to
obtain any documentation from a governmental authority or a third party that may
be necessary or reasonable helpful in connection with any of the foregoing.

                                       10
<PAGE>

         5.2 Record Retention; Access. the GLC Group and the OSCA Group shall
each (a) until the expiration of the relevant statute of limitations (including
any extensions of which it has actual notice), retain records, documents,
accounting data and other information (including computer data) necessary for
the preparation and filing of all Tax Returns in respect of Taxes of the GLC
Group or the OSCA Group or for the audit of such Tax Returns; and (b) give to
the other party reasonable access to such records, documents, accounting data
and other information (including computer data) and to its personnel (insuring
their cooperation) and premises, for the purpose of the review or audit of such
Tax Returns to the extent relevant to an obligation or liability of a party
under this Agreement. Prior to destroying any records, documents, data or other
information in accordance with this Article, the party wishing to destroy such
items will give the other party a reasonable opportunity to obtain such items
(at such other party's expense).

         5.3 Information Confidential. GLC (and each member of the GLC Group)
and OSCA (and each member of the OSCA Group) shall hold and cause its
consultants and advisors to hold in strict confidence, unless compelled to
disclose by judicial or administrative process or, in the opinion of its
counsel, by other requirements of law, all information (other than any such
information relating solely to the business or affairs of such party) concerning
the other party furnished to it by the other party or its representatives
pursuant to this Agreement (except to the extent that such information was (i)
in the public domain through no fault of the party to which it was furnished, or
(ii) lawfully acquired from other sources by such party), and shall not release
or disclose such information to any other person, except its auditors,
attorneys, financial advisors, bankers and other consultants and advisors who
shall be advised of the provisions of this Section 5.3. Any disclosure of
information by either party to accountants for review purposes pursuant to
sections of the Agreement providing for review rights shall not constitute a
breach of confidentiality under this Agreement.

                                   ARTICLE VI

                               DISPUTE RESOLUTION

         6.1 Intent of Parties. Except as otherwise provided in this Agreement,
it is the intent of the parties that the OSCA Group federal, state, local and
foreign Tax liability for all taxable periods, beginning with the tax period
that includes the IPO Date, will be determined as if the OSCA Group were a
separate affiliated group of corporations filing a consolidated federal Income
Tax Return, and that OSCA shall pay such liability. This Agreement shall at all
times be interpreted consistently with such intent.

         6.2 Dispute Resolution. In the event that GLC, on the one hand, and
OSCA, on the other hand, disagree as to the amount or calculation of any payment
to be made under this Agreement, or the interpretation or application of any
provision under this Agreement, the parties


                                       11
<PAGE>

shall attempt in good faith to resolve such dispute. If such dispute is not
resolved within sixty (60) business days following the commencement of the
dispute, GLC and OSCA shall jointly retain a tax attorney that is a member of a
nationally recognized law firm or "big five" accounting firm, which firm is
independent of both parties (the "Independent Firm"), to resolve the dispute.
The Independent Firm shall act as an arbitrator to resolve all points of
disagreement and its decision shall be final and binding upon all parties
involved. Following the decision of the Independent Firm, GLC and OSCA shall
each take or cause to be taken any action necessary to implement the decision of
the Independent Firm. The fees and expenses relating to the Independent Firm
shall be borne equally by GLC and OSCA.


                                   ARTICLE VII

                            MISCELLANEOUS PROVISIONS

         7.1 Termination. Notwithstanding any other provision in this Agreement,
any liabilities determined under this Agreement shall not terminate any earlier
than 60 days after the expiration of the applicable statute of limitation for
such liability. All other representations, warranties and covenants under this
Agreement shall survive indefinitely.

         7.2 Notices. Every notice, request, statement, or bill or other
communication provided for in this Agreement (a "Notice") must be in writing and
may be personally served, provided a receipt is obtained, or may be sent by
certified mail, return receipt requested, postage prepaid, or may be sent by
facsimile, with acknowledgment of receipt requested, to the parties at the
following addresses (or such other address as one party may specify by Notice to
the other parties):

         If to GLC:

                 Great Lakes Chemical  Corporation
                 500 East 96th Street
                 Indianapolis, Indiana 46240
                 Attention: General Counsel
                 Telecopy No.: (317) 715-3050

         with a copy (which shall not constitute effective notice) to:

                 Great Lakes Chemical Corporation
                 500 East 96th Street
                 Indianapolis, Indiana 46240
                 Attention: Director of Taxes
                 Telecopy No.: (317) 715-3050


                                       12
<PAGE>

         If to OSCA:

                 OSCA, Inc.
                 156 Commission Boulevard
                 Lafayette, Louisiana 70598
                 Attention: Chief Financial Officer
                 Telecopy: (318) 837-5211


         with a copy (which shall not constitute effective notice) to:

                 OSCA, Inc.
                 156 Commission Boulevard
                 Lafayette, Louisiana 70598
                 Attention: General Counsel
                 Telecopy: (318) 837-5211

A Notice which is delivered personally is given as of the date specified in the
written receipt. A Notice sent by certified mail is given on the third Business
Day following the date of mailing. A Notice by facsimile is given on the date it
is transmitted, provided that acknowledgment of receipt is received by sender.

         7.3 Governing Law. All issues and questions concerning the
construction, validity, enforcement and interpretation of this Agreement shall
be governed by, and construed in accordance with, the laws of the State of
Indiana, without giving effect to any choice of law or conflict of law rules or
provisions (whether of the State of Indiana or any other jurisdiction) that
would cause the application of the laws of any jurisdiction other than the State
of Indiana.

         7.4 Change in Law. If, due to any change in applicable law or
regulation or the interpretation thereof by any court of law or other governing
body having jurisdiction, subsequent to the date of the Agreement, performance
of any provision of or any transaction contemplated by this Agreement shall
become impracticable or impossible, the parties will use their best efforts to
find and employ an alternative means to achieve the same or substantially the
same result as that contemplated by this Agreement.

         7.5 Treatment of Payments. The parties hereto shall treat any payments
made pursuant to the terms of this Agreement as a capital transaction for all
tax purposes, except to the extent such payments represent interest paid
pursuant to Section 2.7.

         7.6 Binding Effect; No Assignment; Third Party Beneficiaries. This
Agreement shall be binding on, and shall inure to the benefit of, the parties
and their respective successors and assigns. GLC and OSCA hereby guarantee the
performance of all actions, agreements and obligations provided for under this
Agreement of each member of the GLC Group and the OSCA

                                       13
<PAGE>

Group, respectively. GLC or OSCA shall not assign any of its rights or delegate
any of its duties under this Agreement without the prior written consent of the
other party. No person (including, without limitation, any employee of a party
or any stockholder of a party) shall be, or shall be deemed to be, a third party
beneficiary of this Agreement.

         7.7 Entire Agreement; Amendments. This Agreement constitutes the entire
agreement of the parties concerning the subject matter hereof and supersedes all
prior agreements, whether or not written, concerning such subject matter. The
provisions of this Agreement may not be amended and parties hereto may not take
any action herein prohibited, or fail to perform any act herein required to be
performed by it, unless such party has obtained the prior written consent of the
other party. No other course of dealing among the parties hereto or any delay in
exercising any rights hereunder or shall operate as a waiver of any rights
hereunder. The parties recognize and acknowledge their intention to enter into
additional agreements from time to time with respect to the allocation of taxes
not covered by this Agreement.

         7.8 Counterparts. This Agreement may be executed in one or more
counterparts, each of which shall be an original and all of which shall
constitute together the same document.

         7.9 Interpretation; Descriptive Headings. Whenever the words "include,"
"includes" or "including" are used in this Agreement, they shall be deemed to be
followed by the words "without limitation." The words describing the singular
number shall include the plural and vice versa. The descriptive headings of this
Agreement are inserted for convenience only and do not constitute a substantive
part of this Agreement.

         7.10 Successors and Assigns. This Agreement shall inure to the benefit
of, and be binding upon the parties and their respective successors,
predecessors and assigns, but no assignment of this Agreement shall relieve any
party of its obligations without the written consent of the other party.

                                    * * * * *


                                       14
<PAGE>

         IN WITNESS WHEREOF, the parties hereto have duly executed this Tax
Disaffiliation Agreement as of the day and year first above written.

                                     GREAT LAKES CHEMICAL CORPORATION




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



                                     OSCA, INC.




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



                                       15