<PAGE>

                                                                    EXHIBIT 10.5
                                                                    ------------


                                    FORM OF
                         REGISTRATION RIGHTS AGREEMENT
                         -----------------------------

          This REGISTRATION RIGHTS AGREEMENT (this "Agreement"), is made and
                                                    ---------
entered into as of May __, 2000, between Great Lakes Chemical  Corporation, a
Delaware corporation ("GLC"), and OSCA, Inc., a Delaware corporation and a
                       ---
wholly owned subsidiary of GLC (the "Company").
                                     -------

          WHEREAS, GLC and OSCA have previously entered into a Master Separation
Agreement and certain ancillary agreements, each effective as of May ___, 2000;

          WHEREAS, GLC currently owns all of the issued and outstanding shares
of the Company's common stock (the "Common Stock");
                                    ------------

          WHEREAS, the Company is offering and selling to the public (the "IPO")
                                                                           ---
by means of a Registration Statement (File No. 333-31956) initially filed with
the Securities and Exchange Commission (the "SEC") on Form S-1 on March 8, 2000
                                             ---
(the "Registration Statement") shares of its Common Stock;
      ----------------------

          WHEREAS, GLC currently intends to evaluate its strategic options with
respect to its entire ownership interest in OSCA remaining after the IPO;

          WHEREAS, GLC and the Company desire to make certain arrangements to
provide GLC with registration rights with respect to shares of Common Stock it
holds;

          NOW THEREFORE, in consideration of the mutual covenants and agreements
set forth herein and for other good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged and intending to be legally bound
hereby, the parties hereby agree as follows:

          Section 1.  Effectiveness of Agreement; Term.
          ---------   --------------------------------

          1.1  Effective Date.  This Agreement shall become effective upon the
               --------------
consummation of the IPO (the "Effective Date").
                              --------------

          1.2  Shares Covered.  This Agreement covers those shares of Common
               --------------
Stock that are held by GLC immediately following the IPO (subject to the
provisions of Section 7, the "Shares").  The "Shares" shall include any
                              ------
securities issued or issuable with respect to the Shares by way of a stock
dividend or a stock split or in connection with a combination of shares,
recapitalization, merger, consolidation or other reorganization.
<PAGE>

          GLC and any Permitted Transferees (as defined in Section 2.5) are each
referred to herein as a "Holder" and collectively as the "Holders" and the
                         ------                           -------
Holders of Shares proposed to be included in any registration under this
Agreement are each referred to herein as a "Selling Holder" and collectively as
                                            --------------
the "Selling Holders."
     ---------------

          Section 2.  Demand Registration.
          ---------   -------------------

          2.1  Notice.  Upon the terms and subject to the conditions set forth
               ------
herein, upon written notice of any Holder requesting that the Company effect the
registration under the Securities Act of 1933, as amended (the "Securities
                                                                ----------
Act"), of any or all of the Shares held by it, which notice shall specify the
---
intended method or methods of disposition of such Shares (which methods may
include, without limitation, a Shelf Registration, a Convertible Registration or
an Exchange Registration (as such terms are defined in Section 2.6)), the
Company will promptly give written notice of the proposed registration to all
other Holders and will use its best efforts to effect (at the earliest
reasonable date) the registration under the Securities Act of such Shares (and
the Shares of any other Holders joining in such request as are specified in a
written notice received by the Company within 20 days after receipt of the
Company's written notice of the proposed registration) for disposition in
accordance with the intended method or methods of disposition stated in such
request (each registration request pursuant to this Section 2.1 is sometimes
referred to herein as a "Demand Registration"); provided, however, that:
                         -------------------

          (a)  the Company shall not be obligated to effect registration with
respect to Shares pursuant to this Section 2 within 90 days after the effective
date of a previous registration, other than a Shelf Registration, effected with
respect to Shares pursuant to this Section 2;

          (b)  if, while a registration request is pending pursuant to this
Section 2, the Company determines in the good faith judgment of the legal
counsel of the Company that such registration would reasonably be expected to
have a material adverse effect on any existing proposal or plans by the Company
or any of its subsidiaries to engage in any material acquisition, merger,
consolidation, tender offer, other business combination, reorganization,
securities offering or other material transaction, the Company may postpone for
up to 90 days the filing or effectiveness of such registration; provided,
however, that the Company may delay a Demand Registration hereunder only once in
any 12 month period;

          (c)  except in the case of a Convertible Registration or an Exchange
Registration, the number of the Shares registered pursuant to any registration
requested pursuant to this Section 2 shall have an aggregate expected offering
price of at least $25 million; and

          (d)  if a Demand Registration is an underwritten offering and the
managing underwriters advise the Company in writing that in their opinion the
number of Shares

                                      -2-
<PAGE>

requested to be included in such offering exceeds the number of Shares which can
be sold in an orderly manner in such offering within a price range acceptable to
the Holders of a majority of the Shares initially requesting such registration
or without materially adversely affecting the market for the Common Stock, the
Company shall include in such registration the number of Shares requested to be
included therein which in the opinion of such underwriters can be sold in an
orderly manner within the price range of such offering and without materially
adversely affecting the market for the Common Stock, pro rata among the
respective Holders thereof on the basis of the amount of Shares owned by each
Holder requesting inclusion of Shares in such registration.

          2.2  Registration Expenses.  All Registration Expenses (as defined in
               ---------------------
Section 8) for any registration requested pursuant to this Section 2 (including
any registration that is delayed or withdrawn) shall be paid by the Company.

          2.3  Selection of Professionals.  The Holders of a majority of the
               --------------------------
Shares included in any Demand Registration shall have the right to select the
investment banker(s) and manager(s) to administer the offering; provided,
however, that if such Holders select an investment banker or manager that was
not one of the managers of the IPO, such investment banker or manager shall not
administer such offering if the Company reasonably objects thereto.  The Holders
of a majority of the Shares included in any Demand Registration shall have the
right to select the financial printer, the solicitation and/or exchange agent
(if any) and one counsel for the Selling Holders.  The Company shall select its
own outside counsel and independent auditors.

          2.4  Third Person Shares.  The Company shall have the right to cause
               -------------------
the registration of securities for sale for the account of any Person (including
the Company) other than the Selling Holders (the "Third Person Shares") in any
                                                  -------------------
registration of the Shares requested pursuant to this Section 2 so long as the
Third Person Shares are disposed of in accordance with the intended method or
methods of disposition requested pursuant to this Section 2; provided, however,
that the Company shall not have the right to cause the registration of such
securities of such other Persons if the registration requested pursuant to this
Section 2 is a Convertible Registration or an Exchange Registration.

          If a Demand Registration in which the Company proposes to include
Third Person Shares is an underwritten offering and the managing underwriters
advise the Company in writing that in their opinion the number of Shares and
Third Person Shares requested to be included in such offering exceeds the number
of Shares and Third Person Shares which can be sold in an orderly manner in such
offering within a price range acceptable to the Holders of a majority of the
Shares initially requesting such registration or without materially adversely
affecting the market for the Common Stock, the Company shall not include in such
registration any Third Person Shares unless all of the Shares initially
requested to be included therein are so included.

                                      -3-
<PAGE>

          2.5  Permitted Transferees.  As used in this Agreement, "Permitted
               ---------------------                               ---------
Transferees" shall mean any transferee, whether direct or indirect, of Shares
-----------
designated by GLC (or a subsequent holder) in a written notice to the Company as
provided for in Section 9.7.  Any Permitted Transferees of the Shares shall be
subject to and bound by all of the terms and conditions herein applicable to
Holders.  The notice required by this Section 2.5 shall be signed by both the
transferring Holder and the Permitted Transferees so designated and shall
include an undertaking by the Permitted Transferees to comply with the terms and
conditions of this Agreement applicable to Holders.

          2.6  Shelf Registration; Convertible Registration; Exchange
               ------------------------------------------------------
Registration. With respect to any Demand Registration, the requesting Holders
------------
may request the Company to effect a registration of the Shares (a) under a
registration statement pursuant to Rule 415 under the Securities Act (or any
successor rule) (a "Shelf Registration"); (b) in connection with such Holders'
                    ------------------
registration under the Securities Act of securities (the "Convertible
                                                          -----------
Securities") convertible into, exercisable for or otherwise related to the
----------
Shares (a "Convertible Registration"); or (c) in connection with such Holders'
           ------------------------
offer to exchange the Shares for any debt or equity securities of such Holders,
a subsidiary or affiliate thereof or any other Person (an "Exchange
                                                           --------
Registration").
------------

          2.7  SEC Form.  The Company shall use its best efforts to cause Demand
               --------
Registrations to be registered on Form S-3 (or any successor form), and if the
Company is not then eligible under the Securities Act to use Form S-3, Demand
Registrations shall be registered on Form S-1 (or any successor form).  If a
Demand Registration is a Convertible Registration or an Exchange Registration,
the Company shall effect such registration on the appropriate Form under the
Securities Act for such registrations.  The Company shall use its best efforts
to become eligible to use Form S-3 and, after becoming eligible to use Form S-3,
shall use its best efforts to remain so eligible.

          2.8  Other Registration Rights.  The Company shall not grant to any
               -------------------------
Persons the right to request the Company to register any equity securities of
the Company, or any securities convertible or exchangeable into or exercisable
for such securities unless such rights are consistent with the rights granted
under this Agreement.

          Section 3.  Piggyback Registrations.
          ---------   -----------------------

          3.1  Notice and Registration.  If the Company proposes to register any
               -----------------------
of its securities for public sale under the Securities Act (whether proposed to
be offered for sale by the Company or any other Person), on a form and in a
manner which would permit registration of the Shares for sale to the public
under the Securities Act (a "Piggyback Registration"), it will give prompt
                             ----------------------
written notice to the Holders of its intention to do so, and upon the written
request of any or all of the Holders delivered to the Company within 20 days
after the giving of any such notice (which request shall specify the Shares
intended to be disposed of by such Holders), the Company will use its best
efforts to effect, in

                                      -4-
<PAGE>

connection with the registration of such other securities, the registration
under the Securities Act of all of the Shares which the Company has been so
requested to register by such Holders (which shall then become Selling Holders),
to the extent required to permit the disposition (in accordance with the same
method of disposition as the Company proposes to use to dispose of the other
securities) of the Shares to be so registered; provided, however, that:

          (a)  if, at any time after giving such written notice of its intention
to register any of its other securities and prior to the effective date of the
registration statement filed in connection with such registration, the Company
shall determine for any reason not to register such other securities, the
Company may, at its election, give written notice of such determination to the
Selling Holders (or, if prior to delivery of the Holders' written request
described above in this Section 3.1, the Holders) and thereupon the Company
shall be relieved of its obligation to register such Shares in connection with
the registration of such other securities (but not from its obligation to pay
Registration Expenses to the extent incurred in connection therewith as provided
in Section 3.3), without prejudice, however, to the rights (if any) of any
Selling Holders immediately to request (subject to the terms and conditions of
Section 2) that such registration be effected as a registration under Section 2;

          (b)  the Company shall not be required to effect any registration of
the Shares under this Section 3 incidental to the registration of any of its
securities in connection with mergers, acquisitions, exchange offers,
subscription offers, dividend reinvestment plans or stock option or other
employee benefit plans of the Company;

          (c)  if a Piggyback Registration is an underwritten primary
registration on behalf of the Company and the managing underwriters advise the
Company in writing that in their opinion the number of securities requested to
be included in such registration exceeds the number which can be sold in such
offering without materially adversely affecting the marketability of the
offering or the market for the Common Stock, the Company shall include in such
registration (i) first, the securities the Company proposes to sell, (ii)
second, the Shares requested to be included in such registration, pro rata among
the Holders of such Shares on the basis of the number of Shares owned by each
such Holder, and (iii) third, any other securities requested to be included in
such registration; and

          (d)  if a Piggyback Registration is an underwritten secondary
registration on behalf of holders of the Company's securities entitled to demand
registration thereof and the managing underwriters advise the Company in writing
that in their opinion the number of securities requested to be included in such
registration exceeds the number which can be sold in such offering without
materially adversely affecting the marketability of the offering or the market
for the Common Stock, the Company shall include in such registration (i) first,
the securities requested to be included therein by the holders requesting such
registration and the Shares requested to be included in such registration, pro
rata among the holders of such

                                      -5-
<PAGE>

securities on the basis of the number of securities owned by each such holder,
and (ii) second, any other securities requested to be included in such
registration.

          No registration of the Shares effected under this Section 3 shall
relieve the Company of its obligation to effect a registration of Shares
pursuant to Section 2.

          3.2  Selection of Professionals.  If any Piggyback Registration is an
               --------------------------
underwritten offering and any of the investment banker(s) or manager(s) selected
to administer the offering was not one of the managers of the IPO, such
investment banker or manager shall not administer such offering if the Holders
of a majority of the Shares included in such Piggyback Registration reasonably
object thereto.  The Holders of a majority of the Shares included in any
Piggyback Registration shall have the right to select one counsel for the
Selling Holders.  The Company shall select its own outside counsel and
independent auditors.

          3.3  Registration Expenses.  The Company will pay all of the
               ---------------------
Registration Expenses in connection with any registration pursuant to this
Section 3.

          Section 4.  Registration Procedures.
          ---------   -----------------------

          4.1  Registration and Qualification.  If and whenever the Company is
               ------------------------------
required to use its best efforts to effect the registration of any of the Shares
under the Securities Act as provided in Sections 2 and 3, including an
underwritten offering pursuant to a Shelf Registration, the Company will as
promptly as is practicable:

          (a)  prepare and file with the SEC a registration statement with
respect to such Shares and use its best efforts to cause such registration
statement to become effective (provided that before filing a registration
statement or prospectus or any amendments or supplement thereto, the Company
shall furnish to the counsel selected by the Holders of a majority of the Shares
covered by such registration statement copies of all such documents proposed to
be filed (which documents shall be subject to the review and comment of such
counsel);

          (b)  except in the case of a Shelf Registration, Convertible
Registration or Exchange Registration, prepare and file with the SEC such
amendments and supplements to such registration statement and the prospectus
used in connection therewith as may be necessary to keep such registration
statement effective and to comply with the provisions of the Securities Act with
respect to the disposition of all of the Shares until the earlier of (i) such
time as all of such Shares have been disposed of in accordance with the intended
methods of disposition set forth in such registration statement or (ii) the
expiration of nine months after such registration statement becomes effective;

                                      -6-
<PAGE>

          (c)  in the case of a Shelf Registration (but not including any
Convertible Registration), prepare and file with the SEC such amendments and
supplements to such registration statement and the prospectus used in connection
therewith as may be necessary to keep such registration statement effective and
to comply with the provisions of the Securities Act with respect to the
disposition of all Shares subject thereto for a period ending on the earlier of
(i) 18 months after the effective date of such registration statement and (ii)
the date on which all the Shares subject thereto have been sold pursuant to such
registration statement (the "Shelf Effective Period");
                             ----------------------

          (d)  in the case of a Convertible Registration or an Exchange
Registration, prepare and file with the SEC such amendments and supplements to
such registration statement and the prospectus used in connection therewith as
may be necessary to keep such registration statement effective and to comply
with the provisions of the Securities Act with respect to the disposition of all
of the Shares subject thereto until such time as the rules, regulations and
requirements of the Securities Act and the terms of the Convertible Securities
no longer require such Shares to be registered under the Securities Act (the

"Convertible Effective Period");
 ----------------------------

          (e)  furnish to the Selling Holders and to any underwriter of such
Shares such number of conformed copies of such registration statement and of
each such amendment and supplement thereto (in each case including all
exhibits), such number of copies of the prospectus included in such registration
statement (including each preliminary prospectus and any summary prospectus), in
conformity with the requirements of the Securities Act, such documents
incorporated by reference in such registration statement or prospectus, and such
other documents as the Selling Holders or such underwriter may reasonably
request;

          (f)  use its best efforts to register or qualify all of the Shares
covered by such registration statement under such other securities or blue sky
laws of such jurisdictions as the Selling Holders or any underwriter of such
Shares shall reasonably request, and do any and all other acts and things which
may be necessary or advisable to enable the Selling Holders or any underwriter
to consummate the disposition in such jurisdictions of the Shares covered by
such registration statement, except that the Company shall not for any such
purpose be required to qualify generally to do business as a foreign corporation
in any jurisdiction where it is not so qualified, or to subject itself to
taxation in any such jurisdiction, or to consent to general service of process
in any such jurisdiction;

          (g)  (i) furnish to the Selling Holders, addressed to them, an opinion
of counsel for the Company and (ii) use its best efforts to furnish to the
Selling Holders, addressed to them, a "cold comfort" letter signed by the
independent public accountants who have certified the Company's financial
statements included in such registration statement, covering substantially the
same matters with respect to such registration statement (and the prospectus
included therein) and, in the case of such accountants' letter, with respect to
events subsequent to the date of such financial statements, as are customarily
covered in

                                      -7-
<PAGE>

opinions of issuer's counsel and in accountants' letters delivered to
underwriters in underwritten public offerings of securities and such other
matters as the Selling Holders may reasonably request, in each case, in form and
substance and as of the dates reasonably satisfactory to the Selling Holders;

          (h)  immediately notify the Selling Holders, at any time when a
prospectus relating to a registration pursuant to Section 2 or 3 is required to
be delivered under the Securities Act, of the happening of any event as a result
of which the prospectus included in such registration statement, as then in
effect, includes an untrue statement of a material fact or omits to state any
material fact required to be stated therein or necessary to make the statements
therein, in light of the circumstances under which they were made, not
misleading, and at the request of the Selling Holders prepare and furnish to the
Selling Holders a reasonable number of copies of a supplement to or an amendment
of such prospectus as may be necessary so that, as thereafter delivered to the
purchasers of such Shares, such prospectus shall not include an untrue statement
of a material fact or omit to state a material fact required to be stated
therein or necessary to make the statements therein, in light of the
circumstances under which they are made, not misleading.

          (i)  permit any Selling Holder which Selling Holder, in its sole and
exclusive judgment, might be deemed to be an underwriter or a controlling person
of the Company, to participate in the preparation of such registration or
comparable statement and to require the insertion therein of material, furnished
to the Company in writing, which in the reasonable judgment of such Holder and
its counsel should be included;

          (j)  to make available members of management of the Company, as
selected by the Holders of a majority of the Shares included in such
registration, for assistance in the selling effort relating to the Shares
covered by such registration, including, but not limited to, the participation
of such members of the Company's management in road show presentations.

          (k)  in the event of the issuance of any stop order suspending the
effectiveness of a registration statement, or of any order suspending or
preventing the use of any related prospectus or suspending the qualification of
any securities included in such registration statement for sale in any
jurisdiction, the Company shall use it best efforts promptly to obtain the
withdrawal of such order; and

          (l)  use its best efforts to cause Shares covered by such registration
statement to be registered with or approved by such other government agencies or
authorities as may be necessary to enable the sellers thereof to consummate the
disposition of such Shares.

          The Company may require the Selling Holders to furnish the Company
with such information regarding the Selling Holders and the distribution of such
Shares as the Company may from time to time reasonably request in writing and as
shall be required by

                                      -8-
<PAGE>

law, the SEC or any securities exchange on which any shares of Common Stock are
then listed for trading in connection with any registration.

          4.2  Underwriting.  If requested by the underwriters for any
               ------------
underwritten offering in connection with a registration requested hereunder
(including any registration under Section 3 which involves, in whole or in part,
an underwritten offering), the Company will enter into an underwriting agreement
with such underwriters for such offering, such agreement to contain such
representations and warranties by the Company and such other terms and
provisions as are customarily contained in underwriting agreements with respect
to secondary distributions, including, without limitation, indemnities and
contribution to the effect and to the extent provided in Section 6 and the
provision of opinions of counsel and accountants' letters to the effect and to
the extent provided in Section 4.1(g).  The Company may require that the Shares
requested to be registered pursuant to Section 3 be included in such
underwriting on the same terms and conditions as shall be applicable to the
Other Securities being sold through underwriters under such registration;
provided , however, that no Selling Holder shall be required to make any
representations or warranties to the Company or the underwriters (other than
representations and warranties regarding such Holder and such Holder's intended
method of distribution) or to undertake any indemnification obligations to the
Company or the underwriters with respect thereto, except as otherwise provided
in Section 6 hereof.  The Selling Holders shall be parties to any such
underwriting agreement, and the representations and warranties by, and the other
agreements on the part of, the Company to and for the benefit of such
underwriters shall also be made to and for the benefit of such Selling Holders.

          4.3  Blackout Periods for Shelf Registrations.
               ----------------------------------------

          (a)  At any time when a Shelf Registration effected pursuant to
Section 2 relating to the Shares is effective, upon written notice from the
Company to the Selling Holders that the Company determines in the good faith
judgment of the general counsel of the Company that the Selling Holders' sale of
the Shares pursuant to the Shelf Registration would require disclosure of
material information which the Company has a bona fide business purpose for
preserving as confidential and the disclosure of which would have a material
adverse effect on the Company or the Company is unable to comply with SEC
requirements (an "Information Blackout"), the Selling Holders shall suspend
                  --------------------
sales of the Shares pursuant to such Shelf Registration until the earlier of (i)
the date upon which such material information is disclosed to the public or
ceases to be material, (ii) 90 days after the general counsel of the Company
makes such good faith determination or (iii) such time as the Company notifies
the Selling Holders that sales pursuant to such Shelf Registration may be
resumed (the number of days from such suspension of sales of the Selling Holders
until the day when such sales may be resumed hereunder is hereinafter called a

"Sales Blackout Period").
 ---------------------

                                      -9-
<PAGE>

          (b)  If there is an Information Blackout and the Selling Holders do
not notify the Company in writing of their desire to cancel such Shelf
Registration, the period set forth in Section 4.1(c)(i) shall be extended for a
number of days equal to the number of days in the Sales Blackout Period.

          4.4  Listing.  In connection with the registration of any offering of
               -------
the Shares pursuant to this Agreement, the Company agrees to use its best
efforts to effect the listing of such Shares on any securities exchange on which
any shares of the Common Stock are then listed or otherwise facilitate the
public trading of such Shares.

          4.5  Holdback Agreements.
               -------------------

          (a)  The Company shall not effect any public sale or distribution of
its equity securities, or any securities convertible into or exchangeable or
exercisable for such securities, during the seven days prior to and during the
90-day period beginning on the effective date of any registration statement in
connection with a Demand Registration (other than a Shelf Registration) or a
Piggyback Registration, except pursuant to registrations on Form S-8 or any
successor form or unless the underwriters managing any such public offering
otherwise agree.

          (b)  If the Holders of Shares notify the Company in writing that they
intend to effect an underwritten sale of Shares registered pursuant to a Shelf
Registration pursuant to Section 2 hereof, the Company shall not effect any
public sale or distribution of its equity securities, or any securities
convertible into or exchangeable or exercisable for its equity securities,
during the seven days prior to and during the 90-day period beginning on the
date such notice is received, except pursuant to registrations on Form S-8 or
any successor form or unless the underwriters managing any such public offering
otherwise agree.

          (c)  If the Company completes an underwritten registration with
respect to any of its securities (whether offered for sale by the Company or any
other Person) on a form and in a manner that would have permitted registration
of the Shares and no Holder requested the inclusion of any Shares in such
registration, the Holders shall not effect any public sales or distributions of
equity securities of the Company, or any securities convertible into or
exchangeable or exercisable for such securities, until the termination of the
holdback period required from the Company by any underwriters in connection with
such previous registration, which shall not be longer than 90 days from the
effective date of such registration.

          Section 5.  Preparation; Reasonable Investigation.  In connection with
          ---------   -------------------------------------
the preparation and filing of each registration statement registering the Shares
under the Securities Act and each sale of the Shares thereunder, the Company
will give the Selling Holders and the underwriters, if any, and their respective
counsel and accountants, access to its financial and other records, pertinent
corporate documents and properties of the Company

                                      -10-
<PAGE>

and such opportunities to discuss the business of the Company with its officers
and the independent public accountants who have certified its financial
statements as shall be necessary, in the opinion of the Selling Holders and such
underwriters or their respective counsel, to conduct a reasonable investigation
within the meaning of the Securities Act.

          Section 6.  Indemnification and Contribution.
          ---------   --------------------------------

          (a)  In the event of any registration of any of the Shares hereunder,
the Company will enter into customary indemnification arrangements to indemnify
and hold harmless each of the Selling Holders, each of their respective
directors and officers, each Person (as defined in (e) below) who participates
as an underwriter in the offering or sale of such securities, each officer and
director of each underwriter, and each Person, if any, who controls each such
Selling Holder or any such underwriter within the meaning of the Securities Act
(collectively, the "Covered Persons") against any losses, claims, damages,
                    ---------------
liabilities and expenses, joint or several, to which such Person may be subject
under the Securities Act or otherwise insofar as such losses, claims, damages,
liabilities or expenses (or actions or proceedings in respect thereof) arise out
of are based upon (i) any untrue statement or alleged untrue statement of any
material fact contained in any related registration statement filed under the
Securities Act, any preliminary prospectus or final prospectus included therein,
or any amendment or supplement thereto, or any document incorporated by
reference therein, or (ii) any omission or alleged omission to state therein a
material fact required to be stated therein or necessary to make the statements
therein not misleading, and the Company will reimburse each such Covered Person,
as incurred, for any legal or any other expenses reasonably incurred by such
Covered Person in connection with investigating or defending any such loss,
claim, liability, action or proceeding; provided, however, that the Company
shall not be liable in any such case to the extent that any such loss, claim,
damage, liability (or action or proceeding in respect thereof) or expense arises
out of or is based upon an untrue statement or alleged untrue statement or
omission or alleged omission made in such registration statement, any such
preliminary prospectus or final prospectus, amendment or supplement in reliance
upon and in conformity with written information furnished to the Company by such
Selling Holder or such underwriter specifically for use in the preparation
thereof.  Such indemnity shall remain in full force and effect regardless of any
investigation made by or on behalf of any such Covered Person and shall survive
the transfer of such securities by the Selling Holders.  The Company also shall
agree to provide for contribution as shall reasonably be requested by the
Selling Holders or any underwriters in circumstances where such indemnity is
held unenforceable.

          (b)  Each of the Selling Holders, by virtue of exercising its
respective registration rights hereunder, agree and undertake to enter into
customary indemnification arrangements to indemnify and hold harmless (in the
same manner and to the same extent as set forth in clause (a) of this Section 6)
the Company, its directors and officers, each Person who participates as an
underwriter in the offering or sale of such securities, each officer and
director of each underwriter, and each Person, if any, who controls the Company

                                      -11-
<PAGE>

or any such underwriter within the meaning of the Securities Act, with respect
to any statement in or omission from such registration statement, any
preliminary prospectus or final prospectus included therein, or any amendment or
supplement thereto, if such statement or omission is contained in written
information furnished by such Selling Holder to the Company specifically for
inclusion in such registration statement or prospectus; provided, however, that
the obligation to indemnify shall be individual, not joint and several, for each
Selling Holder and shall be limited to the net amount of proceeds received by
such Selling Holder from the sale of Shares pursuant to such registration
statement.  Such indemnity shall remain in full force and effect regardless of
any investigation made by or on behalf of the Company or any such director,
officer or Person and shall survive the transfer of the registered securities by
the Selling Holders.

          (c)  Any Person entitled to indemnification hereunder shall (i) give
prompt written notice to the indemnifying party of any claim with respect to
which it seeks indemnification (provided, however, that the failure to give
prompt notice shall not impair any Person's rights to indemnification hereunder
to the extent such failure has not prejudiced the indemnifying party) and (ii)
unless in such indemnified party's reasonable judgment a conflict of interest
between such indemnified and indemnifying parties may exist with respect to such
claim, permit such indemnifying party to assume the defense of such claim with
counsel reasonably satisfactory to the indemnified party.  If such defense is
assumed, the indemnifying party shall not be subject to any liability for any
settlement made by the indemnified party without its consent (but such consent
shall not be unreasonably withheld). An indemnifying party who is not entitled
to, or elects not to, assume the defense of a claim shall not be obligated to
pay the fees and expenses of more than one counsel for all parties indemnified
by such indemnifying party with respect to such claim, unless in the reasonable
judgment of any indemnified party a conflict of interest may exist between such
indemnified party and any other of such indemnified parties with respect to such
claim.

          (d)  Indemnification and contribution similar to that specified in the
preceding subdivisions of this Section 6 (with appropriate modifications) shall
be given by the Company and the Selling Holders with respect to any required
registration or other qualification of such Shares under any federal or state
law or regulation of governmental authority other than the Securities Act.

          (e)  "Person" means an individual, a partnership, a corporation, a
                ------
limited liability company, an association, a joint stock company, a trust, a
joint venture, an unincorporated organization and a governmental entity, or any
department, agency or political subdivision thereof.

          Section 7.  Benefits and Termination of Registration Rights.  The
          ---------   -----------------------------------------------
Holders may exercise the registration rights granted hereunder in such manner
and proportions as they shall agree among themselves. The registration rights
hereunder shall cease to apply to any particular Shares and such securities
shall cease to be Shares when: (a) a registration

                                      -12-
<PAGE>

statement with respect to the sale of such Shares shall have become effective
under the Securities Act and such Shares shall have been disposed of in
accordance with such registration statement; (b) such Shares shall have been
sold to the public pursuant to Rule 144 under the Securities Act (or any
successor provision); (c) such Shares shall have been otherwise transferred, new
certificates for them not bearing a legend restricting further transfer shall
have been delivered by the Company and subsequent public distribution of them
shall not require registration or qualification of them under the Securities Act
or any similar state law then in force; (d) such Shares shall have ceased to be
outstanding or (e) in the case of Shares held by a Permitted Transferee, when
such Shares become eligible for sale pursuant to Rule 144(k) under the
Securities Act (or any successor provision).

          Section 8.  Registration Expenses.  As used in this Agreement, the
          ---------   ---------------------
term "Registration Expenses" means all expenses incident to the Company's
      ---------------------
performance of or compliance with the registration requirements set forth in
this Agreement including, without limitation, the following: (a) all
registration and filing fees; (b) the fees, disbursements and expenses of the
Company's counsel and accountants in connection with the registration of the
Shares to be disposed of under the Securities Act; (c) the fees, disbursements
and expenses of the Selling Holders' counsel and advisors in connection with the
registration of the Shares to be disposed of under the Securities Act; (d) all
expenses in connection with the preparation, printing and filing of the
registration statement, any preliminary prospectus or final prospectus, any
other offering document and amendments and supplements thereto and the mailing
and delivering of copies thereof to the underwriters and dealers and directly to
securityholders in the case of an Exchange Registration; (e) the cost of
printing and producing any agreements among underwriters, underwriting
agreements, and blue sky or legal investment memoranda, any selling agreements
and any amendments thereto or other documents in connection with the offering,
sale or delivery of the Shares to be disposed of; (f) all expenses in connection
with the qualification of the Shares to be disposed of for offering and sale
under state securities laws, including the fees and disbursements of counsel for
the underwriters in connection with such qualification and in connection with
any blue sky and legal investment surveys; (g) the filing fees incident to
securing any required review by the New York Stock Exchange and any other
securities exchange on which the Common Stock is then traded or listed of the
terms of the sale of the Shares to be disposed of and the trading or listing of
all such Shares on each such exchange; (h) the costs of preparing stock
certificates; (i) the costs and charges of the Company's transfer agent and
registrar; and (j) the fees and disbursements of any custodians, solicitation
agents, information agents and/or exchange agents.  Registration Expenses shall
not include underwriting discounts and underwriters' commissions attributable to
the Shares being registered for sale on behalf of the Selling Holders, which
shall be paid by the Selling Holders.

          Section 9.  Miscellaneous.
          ---------   -------------

          9.1  No Inconsistent Agreements.  The Company shall not on or after
               --------------------------
the date of this Agreement enter into any agreement with respect to its
securities that violates or

                                      -13-
<PAGE>

subordinates the rights expressly granted to the Holders in this Agreement. The
Company shall not take any action, or permit any change to occur, with respect
to its securities which would adversely affect the ability of the Holders of
Shares to include such Shares in a registration undertaken pursuant to this
Agreement.

          9.2  Complete Agreement.  Except as otherwise set forth in this
               ------------------
Agreement, this Agreement shall constitute the entire agreement between the
parties hereto with respect to the subject matter hereof and shall supersede all
prior agreements and understandings, whether written or oral, between the
parties with respect to such subject matter.

          9.3  Authority.  Each of the parties hereto represents to the other
               ---------
that (i) it has the corporate power and authority to execute, deliver and
perform this Agreement, (ii) the execution, delivery and performance of this
Agreement by it has been duly authorized by all necessary corporate action,
(iii) it has duly and validly executed and delivered this Agreement, and (iv)
this Agreement is a legal, valid and binding obligation, enforceable against it
in accordance with its terms subject to applicable bankruptcy, insolvency,
reorganization, moratorium or other similar laws affecting creditors' rights
generally and general equity principles.

          9.4  Assignment.  This Agreement shall be binding on and inure to the
               ----------
benefit of and be enforceable by the parties hereto and with respect to the
Company, its respective successors and assigns, and any Permitted Transferees.

          9.5  Governing Law.  This Agreement shall be governed by and construed
               -------------
in accordance with the laws of the State of Delaware (other than the laws
regarding conflicts of laws) as to all matters of validity, construction,
effect, performance and remedies, executed in and to be performed in that State.

          9.6  Severability.  In the event that any part of this Agreement is
               ------------
declared by a court or other judicial or administrative body to be null, void or
unenforceable, said provision shall survive to the extent it is not so declared,
and all of the other provisions of this Agreement shall remain in full force and
effect.

          9.7  Notices.  All notices, requests, demands and other communications
               -------
under this Agreement shall be in writing and shall be deemed to have been duly
given: (i) on the date of service if served personally on the party to whom
notice is to be given; (ii) on the day of transmission if sent via facsimile
transmission to the facsimile number given below, and telephonic confirmation of
receipt is obtained promptly after completion of transmission; (iii) on the day
after delivery to Federal Express or similar overnight courier or the Express
Mail service maintained by the United States Postal Service; or (iv) on the
fifth day after mailing, if mailed to the party to whom notice is to be given,
by first class mail, registered or certified, postage prepaid and properly
addressed, to the party as follows:

                                      -14-
<PAGE>

          If to GLC:

          Great Lakes Chemical Corporation
          500 East 96/th/ Street
          Indianapolis, Indiana 46240
          Attention:  General Counsel
          Facsimile:  (317) 705-6415

          If to any other Holder, the address indicated for such Holder in the
Company's stock transfer records with a copy, so long as GLC owns any Shares,
to:

          Great Lakes Chemical Corporation
          500 East 96/th/ Street
          Indianapolis, Indiana 46240
          Attention:  General Counsel
          Facsimile:  (317) 705-6415

          If to the Company:

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

          Any party may change its address for the purpose of this Section 9.7
by giving the other party written notice of its new address in the manner set
forth above.

          9.8  Severability.  Any provision of this Agreement which is
               ------------
prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction,
be ineffective to the extent of such prohibition or unenforceability without
invalidating the remaining provisions hereof. Any such prohibition or
unenforceability in any jurisdiction shall not invalidate or render
unenforceable such provision in any other jurisdiction.

          9.9  Remedies.  Each of GLC and the Company shall be entitled to
               --------
enforce its rights under this Agreement specifically, to recover damages and
costs (including reasonable attorneys' fees) caused by any breach of any
provision of this Agreement and to exercise all other rights existing in its
favor. Each of GLC and the Company acknowledges and agrees that under certain
circumstances the breach by GLC or any of its affiliates or the Company or any
of its affiliates of a term or provision of this Agreement will materially and
irreparably harm the other party, that money damages will accordingly not be an
adequate remedy for such breach and that the non-defaulting party, in its sole
discretion and in addition to its rights under this Agreement and any other
remedies it may have at law or in

                                      -15-
<PAGE>

equity, may apply to any court of law or equity of competent jurisdiction
(without posting any bond or deposit) for specific performance and/or other
injunctive relief in order to enforce or prevent any breach of the provisions of
this Agreement.

          9.10 Waivers.  The observance of any term of this Agreement may be
               -------
waived (either generally or in a particular instance and either retroactively or
prospectively) by the party entitled to enforce such term, but such waiver shall
be effective only if it is in writing signed by the Company and the Holders of a
majority of the Shares.  Unless otherwise expressly provided in this Agreement,
no delay or omission on the part of any party in exercising any right or
privilege under this Agreement shall operate as a waiver thereof, nor shall any
waiver on the part of any party of any right or privilege under this Agreement
operate as a waiver of any other right or privilege under this Agreement nor
shall any single or partial exercise of any right or privilege preclude any
other or further exercise thereof or the exercise of any other right or
privilege under this Agreement.  No failure by either party to take any action
or assert any right or privilege hereunder shall be deemed to be a waiver of
such right or privilege in the event of the continuation or repetition of the
circumstances giving rise to such right unless expressly waived in writing by
the party against whom the existence of such waiver is asserted.

          9.11 Amendment and Modification.  This Agreement may not be amended
               --------------------------
or modified in any respect except by a written agreement signed by the Company
and the Holders of a majority of the Shares.

          9.12 Section and Paragraph Headings.  The section and paragraph
               ------------------------------
headings in this Agreement are for reference purposes only, are not part of the
agreement of the parties hereto, and shall not affect the meaning or
interpretation of this Agreement.  All references to days or months shall be
deemed references to calendar days or months.  All references to "$" shall be
deemed references to United States dollars.  Unless the context otherwise
requires, any reference to a "Section" shall be deemed to refer to a section of
this Agreement. The words "hereof," "herein" and "hereunder" and words of
similar import referring to this Agreement refer to this Agreement as a whole
and not to any particular provision of this Agreement.  Whenever the words
"include," "includes" or "including" are used in this Agreement, unless
otherwise specifically provided, they shall be deemed to be followed by the
words "without limitation." This Agreement shall be construed without regard to
any presumption or rule requiring construction or interpretation against the
party drafting or causing the document to be drafted.

          9.13 Counterparts.  This Agreement may be executed in two or more
               ------------
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.  This Agreement may be
executed by facsimile signature.

                                      ***

                                      -16-
<PAGE>

          IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be duly executed and delivered as of the date and year first written above.



                         GREAT LAKES CHEMICAL CORPORATION


                         By  _______________________________
                         Its _______________________________


                         OSCA, INC.



                         By  _______________________________
                         Its _______________________________

                                      -17-