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                                                                    Exhibit 10.8

                              TAX SHARING AGREEMENT

            THIS TAX SHARING AGREEMENT made as of the 1st day of January, 2001,
by and among International Specialty Products Inc., a Delaware corporation
("ISP"), Newco Holdings Inc., a Delaware corporation ("Holdings") and ISP Chemco
Inc. (formerly known as ISP OPCO Holdings, Inc.), a Delaware corporation
("CHEMCO").

            WHEREAS, ISP 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 each of Holdings and CHEMCO is a member of
said affiliated group;

            WHEREAS, the ISP Group (as hereinafter defined) files consolidated
federal income tax returns;

            WHEREAS, predecessors to several of the parties hereto are parties
to a Tax Sharing Agreement dated as of January 1, 1997 (the "Old Tax Sharing
Agreement");

            WHEREAS, CHEMCO is wholly-owned by Holdings; and

            WHEREAS, Holdings and CHEMCO wish to provide for a new allocation
among them of their shares of the consolidated federal income tax liability of
said affiliated group and certain related matters;

            NOW, THEREFORE, in consideration of the foregoing premises and of
the mutual covenants contained herein, it is agreed as follows:
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            1.    DEFINITIONS

                  a.    Where applicable, terms used in this Agreement shall
have the meanings ascribed to them in, and shall be interpreted in accordance
with, the Code, and the regulations and rulings issued thereunder, as in effect
from time to time.

                  b.    For purposes of this Agreement, the terms set forth
below shall be defined as follows:

                        (i)   ISP Group -- ISP, Holdings, CHEMCO and all
corporations (whether now existing or hereafter formed or acquired) that at the
time join with ISP (or any successor common parent corporation) in filing a
consolidated federal income tax return.

                        (ii)  Parent -- ISP, or any successor common parent
corporation of the ISP Group.

                        (iii) Base Rate -- the interest rate applicable from
time to time under the Credit Agreement.

                        (iv)  CHEMCO -- CHEMCO, or any successor corporation.

                        (v)   CHEMCO Group -- CHEMCO and any subsidiary
corporation (whether now existing or hereafter formed or acquired) which (1)
would be included in the affiliated group of corporations (as defined in Section
1504(a) of the Code) of which CHEMCO would be the common parent but for the
inclusion of CHEMCO in the ISP Group and (2) is either a "Borrower" or a
"Restricted Subsidiary" under the Credit Agreement.


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                        (vi)  Credit Agreement -- the Credit Agreement dated as
of June 27, 2001 among CHEMCO, individually and as lead borrower, several of its
Subsidiaries, The Chase Manhattan Bank, as Administrative Agent, and various
lenders.

                        (vii) Holdings -- Holdings, or any successor
corporation.

                        (viii) ISP Group Actual Tax Liability -- The
consolidated federal income tax liability reported on the consolidated federal
income tax return filed by the ISP Group for the taxable year.


                        (ix)  CHEMCO Group Tax Liability -- The hypothetical
consolidated federal income tax liability, determined at the end of the taxable
year, of the CHEMCO Group computed as if the CHEMCO Group had filed its own
consolidated federal income tax return for such taxable year and all prior
taxable years beginning January 1, 2001 or thereafter during the term of this
Agreement; provided, that an item which was not taken into account in
calculating the CHEMCO Group Tax Liability in any such prior year by reason of
the limitations set forth in this definition shall be carried forward to the
subsequent year (if the carryforward of such item shall not have expired under
applicable provisions of the Code) and shall be taken into account in computing
the CHEMCO Group Tax Liability in such subsequent year, subject to the
limitations set forth in this definition: (1) subject to the modifications
specified in Treas. Reg. Sec. 1.1552-1(a)(2)(ii), other than the modifications
specified in Treas. Reg. Sec. 1.1552-1(a)(2)(ii)(a) and Treas. Reg. Sec.
1.1552-1(a)(2)(ii)(b); (2) using the highest marginal federal income tax
corporate rate applicable to such taxable year; (3) using the same elections and
methods of accounting as are used with respect to the CHEMCO Group in the
determination of the ISP Group Actual Tax Liability; (4) except in the case of
foreign


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tax credits, using an amount of the CHEMCO Group deduction, loss or credit
(whether currently or as a carryback or carryforward) to offset the CHEMCO
Group's hypothetical consolidated federal taxable income (or, in the case of
credits against tax, liability for tax) only when and to the extent such
deduction, loss or credit reduces the ISP Group Actual Tax Liability or reduces
the ISP Group actual consolidated federal taxable income for such year during
the term of this Agreement (taking any carryback or carryforward of such
deduction, loss or credit into account on a pro rata basis with those of all
members of the ISP Group other than the CHEMCO Group); provided, that the
limitation in this clause (4) shall not apply to those items ("CHEMCO Group
Excepted Items") of deduction, loss or credit for the taxable year or those
items comprising the net operating loss deduction, in both cases to the extent
such items are not subject to a specific limitation under the Code (e.g., in the
case of an CHEMCO Group capital loss, the limitation in this clause (4) shall
apply (i.e., it can be used only when and to the extent such loss reduces the
ISP Group Actual Tax Liability or reduces the ISP Group actual consolidated
federal taxable income for such year during the term of this Agreement) and in
the case of an ordinary and necessary business expense of the CHEMCO Group the
limitation in this clause (4) shall not apply); (5) using an amount of the
CHEMCO Group foreign tax credit in any taxable year to offset the CHEMCO Group's
hypothetical consolidated federal tax liability for such year as follows: (A) if
the ISP Group Actual Tax Liability for such taxable year (determined without
regard to the CHEMCO Group's foreign tax credit for such year) does not exceed
$12,000,000, using an amount of the CHEMCO Group's foreign tax credit generated
in such taxable year not to exceed $12,000,000; provided, if the ISP Group
Actual Tax Liability for such taxable year


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exceeds zero by reason of income attributable to CHEMCO, the amount of CHEMCO's
foreign tax credit utilized in such taxable year would be reduced by the amount
of such excess; (B) if the ISP Group Actual Tax Liability for such taxable year
(determined without regard to the CHEMCO Group's foreign tax credit for such
year) exceeds $12,000,000, using an amount of the CHEMCO Group's foreign tax
credit generated in such taxable year not to exceed the amount of foreign tax
credit actually utilized by Parent to reduce the ISP Group Actual Tax Liability
for such taxable year (taking such credit into account on a pro rata basis with
those of all members of the ISP Group other than the CHEMCO Group for such
taxable year, but prior to taking into account any carryforward of credits
generated in prior taxable years); and (C) using an amount of carryback and
carryforward of the CHEMCO Group's foreign tax credit only when and to the
extent such credit reduces the ISP Group Actual Tax Liability during the term of
this Agreement (taking such carryforward or carryback into account on a pro rata
basis with those of all members of the ISP Group other than the CHEMCO Group);
and (6) treating all tax attributes of any member of the ISP Group for any
taxable year beginning before January 1, 2001 as belonging to the ISP Group
(other than the CHEMCO Group). The CHEMCO Group Tax Liability shall be
determined each taxable year by Holdings in its sole discretion.

                        (x)   CHEMCO Group Estimated Tax Liability -- CHEMCO
Group's Tax Liability, determined through the end of each period for which
estimated federal income tax payments on a consolidated basis are due. The
CHEMCO Group Estimated Tax Liability shall be determined each taxable year by
Holdings in its sole discretion, in accordance with the principles of
subparagraph 1(b)(ix) hereof.


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                        (xi)  CHEMCO Group Tax Refund -- The hypothetical
consolidated federal income tax refund for any year to which the CHEMCO Group
would be entitled, determined in accordance with the principles of subparagraph
1(b)(ix) and using an amount of carryback of CHEMCO Group Excepted Items only
when and to the extent such deduction, loss or credit reduces the ISP Group
Actual Tax Liability or reduces the ISP Group actual consolidated federal
taxable income for such year during the term of this Agreement (taking such
deduction, loss or credit into account on a pro rata basis with those of all
members of the ISP Group other than the CHEMCO Group); provided, such loss,
deduction or credit has not been previously utilized to reduce the CHEMCO Group
Tax Liability or the CHEMCO Group hypothetical consolidated federal taxable
income. The CHEMCO Group Tax Refund shall be determined each taxable year by
Parent in its sole discretion.


                        (xii) R.P. Tax Case -- the tax litigation that includes
Rhone-Poulenc Surfactants and Specialties L.P. v. Commissioner (Tax Court Docket
No. 2125-98) and GAF Corporation and Subsidiaries v. Commissioner (Tax Court
Docket No. 23682-97).

                        (xiii) tax -- regular corporate income tax or corporate
alternative minimum tax and environmental tax together with any and all
interest, additions to tax, fines and penalties payable with respect thereto.


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            2.    PAYMENTS OF CONSOLIDATED FEDERAL INCOME
                  TAX LIABILITY; FILING OF RETURNS

                  a.    Tax Payments by Parent; Filing of Returns

                        Parent shall file consolidated federal income tax
returns and estimated tax returns for each taxable year during the term of this
Agreement, which returns shall include the CHEMCO Group, and shall pay in full
any tax shown on such returns.

                  b.    Payment of CHEMCO Group Tax Liability

                        For each taxable year or portion thereof during which
CHEMCO is included in a consolidated federal income tax return with Parent,
CHEMCO will pay to Holdings an amount equal to the CHEMCO Group Tax Liability.
To the extent that the obligation to pay such amount has not been fully
satisfied pursuant to paragraph 2(c), CHEMCO shall pay any such remaining amount
to Holdings no later than five (5) days prior to the due date for the filing by
Parent of the consolidated federal income tax return for the ISP Group (without
regard to extensions).

                  c.    Estimated Payments

                        On any date on which Parent is to make an estimated
federal income tax payment of the ISP Group on a consolidated basis, CHEMCO will
make an estimated payment to Holdings in an amount equal to the CHEMCO Group
Estimated Tax Liability (reduced by all prior payments required to be made by
CHEMCO under this paragraph 2(c) with respect to the same taxable year). If the
total of such estimated payments made by CHEMCO to Holdings with respect to a
taxable year shall be in excess of the liability of CHEMCO to Holdings pursuant
to paragraph 2(b) for such taxable year, Holdings shall pay the amount of such
excess to CHEMCO, (x) to the


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extent that such excess (or part thereof) represents all or part of a tax refund
to be received by the ISP Group, no later than five (5) days after the receipt
of such refund with an allocable share of interest received thereon (net of tax;
provided, such interest shall not be treated as an item of income of the CHEMCO
Group under this Agreement); (y) to the extent such excess (or part thereof)
represents all or part of a credit against the ISP Group's estimated tax for a
succeeding taxable year, no later than five (5) days after such estimated tax
payments against which such excess is credited is to be paid by the Parent; or
(z) to the extent (x) and (y) do not apply to such excess (or part thereof), no
later than the date on which Parent files the consolidated federal income tax
return for the ISP Group.

                  d.    Tax Refunds

                        (i)   Holdings shall pay to CHEMCO the amount of any
CHEMCO Group Tax Refund for each taxable year ending after the date hereof.

                        (ii)  The payments described in this paragraph 2(d)
shall be made no later than (i) in the case of an actual refund to which the ISP
Group is entitled, five (5) days after such refund is received by Parent on
behalf of the ISP Group or (ii) otherwise, five (5) days after the date on which
Parent files the consolidated federal income tax return for the ISP Group.

            3.    CHANGES IN TAX LIABILITY

                  a.    If any of the ISP Group consolidated federal income tax
returns for taxable years of ISP ending on or after January 1, 2001 is changed
or otherwise adjusted (including, without limitation, by reason of the filing of
an amended return, a "final determination" as defined in Section 1313(a) of the
Code or any of the


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events specified in Section 6213(b) or (d) of the Code), then the amount of the
payment required (1) from CHEMCO to Holdings under paragraph 2(b) or (2) from
Holdings to CHEMCO under paragraph 2(d), as the case may be, shall be recomputed
by substituting the amount of the ISP Group Actual Tax Liability (or the ISP
Group actual consolidated federal taxable income), the CHEMCO Group Tax
Liability (or the CHEMCO Group hypothetical consolidated federal taxable
income), or the CHEMCO Group Tax Refund after the adjustments described above in
place of the ISP Group Actual Tax Liability (or the ISP Group actual
consolidated federal taxable income), the CHEMCO Group Tax Liability (or the
CHEMCO Group hypothetical consolidated federal taxable income), or the CHEMCO
Group Tax Refund as previously computed. Not later than (i) five (5) days prior
to the due date for any additional payment of tax by the ISP Group or five (5)
days after the receipt of a refund or (ii) five (5) days after the event giving
rise to the recomputation if such event will not result in the payment of
additional tax or the receipt of a refund, CHEMCO shall pay to Holdings, or
Holdings shall pay to CHEMCO, as the case may be, the difference between the new
CHEMCO Group Tax Liability (or Refund) and the amounts previously paid. The
parties recognize that such new liability (or Refund) for any taxable year is
not necessarily the ISP Group's or the CHEMCO Group's final liability for that
taxable year, and may be recomputed in accordance with this paragraph 3(a) more
than once.

                  b.    If any of the ISP Group consolidated federal income tax
returns for taxable years of ISP ending on or before January 1, 2001 is changed
or otherwise adjusted (including, without limitation, by reason of the filing of
an amended return, a "final determination" as defined in Section 1313 (a) of the
Code or any of the


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events specified in Section 6213(b) or (d) of the Code), then CHEMCO shall pay
to Holdings an amount equal to any tax that would be payable by it by reason of
any such change or adjustment pursuant to the Old Tax Sharing Agreement. The
parties recognize that such payment for any taxable year is not necessarily the
CHEMCO Group's final liability under this paragraph 3(b) for that taxable year,
and may be recomputed in accordance with this paragraph 3(b) more than once.

                  c.    Payments made pursuant to paragraph (a) shall include an
allocable portion of any interest paid or credited by the Internal Revenue
Service (net of tax; provided, such interest shall not be treated as an item of
income of the CHEMCO Group); payments made pursuant to paragraphs (a) and (b)
shall not themselves bear interest.

            4.    NEW MEMBERS

                  If sufficient stock of any corporation is acquired hereafter
by any member of the CHEMCO Group so that the corporation becomes a member of
the CHEMCO Group ("New Member"), the New Member shall become a party to this
Agreement by delivering to the Parent a written instrument to such effect.
CHEMCO shall use its best efforts, if so requested by ISP, to cause the delivery
of such written instrument and the execution of Form 1122, Authorization and
Consent of Subsidiary Corporation to be Included in a Consolidated Income Tax
Return. The parties hereto hereby agree to the inclusion of any such New Member
as a party to this Agreement.


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            5.    ALLOCATION OF STATE AND LOCAL INCOME TAX
                  LIABILITY

                  a.    In the event that (i) any member of the CHEMCO Group and
(ii) at least one member of the ISP Group not including any member of the CHEMCO
Group elect or are required to file consolidated, combined or unitary state or
local income tax returns or otherwise become liable for state or local income
taxes determined on a consolidated, combined or unitary basis, principles
analogous to those set forth herein for the payment of consolidated federal
income tax liability and refunds thereof shall be used to determine the
respective shares of such taxes and the amount of any payments due CHEMCO from
Holdings on behalf of all members of the ISP Group other than the CHEMCO Group
and the amount and timing of payments to be made in respect thereof.

                  b.    If the ISP Group consolidated, combined or unitary state
or local income tax returns or the separate state or local income tax returns of
ISP or any member of the ISP Group, in both cases for taxable years of ISP
ending on or before January 1, 2001 are changed or otherwise adjusted
(including, without limitation, by reason of the filing of an amended return, a
"final determination" as defined in Section 1313(a) of the Code or any of the
events specified in Section 6213(b) or (d) of the Code), then CHEMCO shall pay
to Holdings an amount equal to any tax that would be payable by it by reason of
any such change or adjustment pursuant to the Old Tax Sharing Agreement. The
parties recognize that such payment for any taxable year is not necessarily the
CHEMCO Group's final liability under this paragraph 5(b) for that taxable year,
and may be recomputed in accordance with this paragraph 5(b) more than once.
Payments made pursuant to this paragraph (b) shall not themselves bear interest.


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            6.    PAYMENT

                  a.    Any payment required by CHEMCO to Holdings under
paragraph 2(b), paragraph 2(c), paragraph 5(a), paragraph 5(b), paragraph 9(c)
or paragraph 9(d) shall (i) with respect to the taxable year beginning January
1, 2001, first be reduced by the amount of any payments made by CHEMCO to ISP
with respect to such taxable year under the Old Tax Sharing Agreement; and (ii)
then be made (1) first, by reducing the amount of any account payable of
Holdings to the CHEMCO Group created under paragraph 6(b) (but not below zero)
and (2) thereafter in cash.

                  b.    Any payment required by Holdings to CHEMCO pursuant to
paragraph 2(d) shall be made at the option of Holdings (i) in cash or (ii) by
entering or increasing an account payable of Holdings to CHEMCO on the books of
account of Holdings; provided that Holdings shall pay to CHEMCO the amount of
any CHEMCO Group Tax Refund for a taxable year ending after the date hereof in
cash if and to the extent that the ISP Group receives a refund from a taxing
authority for such taxable year, together with an allocable share of any
interest received with respect thereto (net of tax; provided, such interest
shall not be treated as an item of income of the CHEMCO Group under this
Agreement); and provided, further, that Holdings shall not pay to CHEMCO an
amount greater than the amount of refund with interest actually received thereon
(net of tax; provided, such interest shall not be treated as an item of income
of the CHEMCO Group under this Agreement) received from the taxing authority.

                  c.    Any account payable created under this paragraph 6 from
Holdings to CHEMCO shall be due on the earlier of (i) such date as Holdings no
longer owns (directly or indirectly) more than 50% of the outstanding stock of
CHEMCO or (ii) the dates of the filing of federal income tax returns of CHEMCO
for taxable years of


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CHEMCO following the last taxable year in which it was a member of the ISP Group
to the extent each such return reflects a tax liability which would have reduced
the account payable under paragraph 6(a) were CHEMCO still a member of the ISP
Group and subject to the terms of this Agreement.

            7.    SPECIAL PROVISIONS REGARDING CHEMCO
                  GROUP'S FOREIGN TAX CREDIT

                  a.    At the end of each taxable year, Holdings shall enter or
increase an account payable of Holdings to CHEMCO in an amount equal to the
excess, if any, of the CHEMCO Group's foreign tax credits for such year (subject
to the foreign tax credits being allowed under CHEMCO Group's separate foreign
tax credit limitation, taking into account carrybacks and carryforwards under
Section 904 of the Code) over the CHEMCO Group's foreign tax credits taken into
account under subparagraph 1(b)(ix)(5)(A) or subparagraph 1(b)(ix)(5)(B) (such
excess being referred to as "Excess Foreign Tax Credits").

                  b.    Such account payable shall be reduced (i) at the end of
each taxable year of CHEMCO during the term of this Agreement to the extent that
Excess Foreign Tax Credits are utilized under subparagraph 1(b)(ix)(5)(C) and
(ii) at the end of each taxable year of CHEMCO following the last taxable year
in which it was a member of the ISP Group to the extent the federal income tax
return of CHEMCO for such taxable year reflects a tax liability which is reduced
by such Excess Foreign Tax Credits (taking such Excess Foreign Tax Credits into
account prior to those of CHEMCO and all other members of the CHEMCO Group).


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                  c.    The balance of such account payable, if any, shall be
paid from time to time on the date that is thirty (30) days following the
expiration of the statute of limitations on assessment of tax for the last year
to which such Excess Foreign Tax Credits or item thereof may be carried forward.

            8.    PROCEDURAL MATTERS

                  Parent shall prepare and file the consolidated federal income
tax returns, consolidated, combined or unitary state or local income tax returns
and any other returns, documents or statements required to be filed with respect
to the determination of the consolidated, combined or unitary federal, state or
local income tax liability of the ISP Group or members thereof for all taxable
years of the ISP Group or members thereof (including taxable years ending prior
to or including the date hereof). In its sole discretion, Parent shall have the
right to make all decisions with respect to such returns and all matters
relating to the federal, state or local income tax liability of the ISP Group
and members thereof for all taxable years of the ISP Group or members thereof
(including taxable years ending prior to or including the date hereof)
including, without limitation, the right (a) to determine (i) the manner in
which such returns, documents or statements shall be prepared and filed,
including, without limitation, the manner in which any item of income, gain,
loss, deduction or credit shall be reported and whether any amended returns
shall be filed, (ii) whether any filing extensions may be requested and (iii)
the elections that will be made by any member, (b) to contest, compromise or
settle any adjustment or deficiency proposed, asserted or assessed as a result
of any audit of such returns, (c) to file, prosecute, compromise or settle any
claim for refund and (d) to determine whether any refunds, to which the ISP
Group may be entitled, shall be paid by


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way of refund or credited against the tax liability for the affiliated group.
Each member of the ISP Group hereby irrevocably appoints Parent as its agent and
attorney-in-fact to take such action (including the execution of documents) as
Parent may deem appropriate to effect the foregoing.

            9.    TERMINATION OF AFFILIATION

                  a.    In the event that any member of the CHEMCO Group ceases
to be included in the ISP Group ("Former Member"), the Parent and the Former
Member shall furnish each other with information required to prepare (i) the
consolidated federal income tax return of the ISP Group for the last taxable
year in which the Former Member had been included in the ISP Group and (ii) the
federal income tax returns for all taxable years thereafter of the Former Member
(and its predecessors and subsidiaries) and the Parent, respectively, in which
the tax liability of either may be affected by their former affiliation
(including, for example, the apportionment of any consolidated net operating or
capital loss or investment or foreign tax credit carryover to the Former
Member). The Former Member shall not, without the prior written consent of the
Parent (which may be withheld by Parent in its sole discretion), file an
application for a carryback adjustment of the tax, for a taxable year in which
the Former Member was included in the ISP Group and a consolidated federal
income tax return was filed, by reason of a net operating loss deduction. The
Former Member may file an application for a carryback adjustment of the tax for
a taxable year in which the Former Member was included in the ISP Group and a
consolidated federal income tax return was filed by reason of a capital loss or
tax credit carryback and shall be entitled to that portion of the actual refund
that is attributable to the Former Member under the consolidated return


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regulations; provided, however, that the Former Member shall not be entitled to
any portion of such refund to the extent the items giving rise to such carryback
have been previously utilized to reduce the CHEMCO Group Tax Liability (or the
CHEMCO Group hypothetical consolidated federal taxable income) or gave rise to
an CHEMCO Group Tax Refund.

                  b.    The Parent and its subsidiaries and the Former Member
shall also furnish each other with all information in their hands as may be
reasonably requested by the other and relates to a taxable year in which the
Former Member had been included in the ISP Group.

                  c.    If the Former Member has a carryforward of a deduction,
loss or credit to a taxable year following the last taxable year in which it
joined in the filing of a consolidated federal income tax return with the ISP
Group which has reduced the CHEMCO Group Tax Liability (or the CHEMCO Group
hypothetical consolidated federal taxable income) or gave rise to an CHEMCO
Group Tax Refund, then CHEMCO shall pay to Holdings, at the time such
carryforward is actually utilized, an amount equal to the benefit derived
therefrom.

                  d.    If the Former Member, in a taxable year following the
last taxable year in which it joined in the filing of a consolidated federal
income tax return with the ISP Group, realizes any tax benefit by reason of any
change or adjustment to the tax attributes, including basis in assets, of any
member of the ISP Group arising from the transactions relating to the formation
of the CHEMCO Group, then CHEMCO shall pay to Holdings at the time such benefits
are actually utilized the amount of benefit derived therefrom.


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                  e. Payments which would have been required under paragraphs 2,
3 or 5 to or by a Former Member, were the Former Member still a member of the
ISP Group, and with respect to taxable year(s) for which the Former Member was a
member of the ISP Group, shall be made in accordance with principles analogous
to those set forth in such paragraph(s) and at the time(s) set forth therein.

            10.   DETERMINATIONS

                  In the case of a dispute, all determinations required
hereunder for each taxable year shall be made by the independent public
accountants regularly employed by Parent at the time the return is filed for
such taxable year. Such determination shall be binding and conclusive upon the
parties for the purposes hereof.

            11.   EFFECTS OF AGREEMENT

                  a.    With respect to the CHEMCO Group, the provisions of this
Agreement shall supercede the Old Tax Sharing Agreement for taxable years
beginning on or after January 1, 2001. As among Holdings and the CHEMCO Group,
the Agreement shall fix the liability of each to the other as to the matters
covered hereunder, even if such provisions are not controlling for tax or other
purposes (including, but not limited to, the computation of earnings and profits
for federal income tax purposes), and even if Holdings and other corporations
which now are, or which from time to time may become, members of the ISP Group
enter into other arrangements for the allocation of the portion of the total tax
liability of the ISP Group which is allocable to them.

                  b.    Except as otherwise provided in paragraph 13(c), this
Agreement shall be effective as of January 1, 2001 and shall remain in effect
for each


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taxable year ending after the date hereof during which CHEMCO or any of its
domestic subsidiaries, as the case may be, is included in a consolidated federal
income tax return filed by the Parent; provided, however, that the provisions of
paragraphs 2, 3, 5, 6, 7, 9, 12 and 13 shall survive until thirty (30) days
after the expiration of the statute of limitations on assessment of tax for the
last year in which CHEMCO or any of its domestic subsidiaries, as the case may
be, was a member of the ISP Group.

            12.   GUARANTY

                  a.    Parent agrees that, to the extent Holdings shall fail to
make any payment required by it to CHEMCO, it will make a payment directly to
CHEMCO within five (5) days after such failure by Holdings.

                  b.    Holdings, in turn, agrees to treat any such payment by
Parent to CHEMCO as a demand loan bearing interest at the Base Rate plus two (2)
percentage points.

            13.   INDEMNITY

                  a.    Each member of the CHEMCO Group agrees, jointly and
severally, to indemnify Parent, Holdings and each other member of the ISP Group
(other than another member of the CHEMCO Group) for the amount of any tax paid
by Parent or such other member which constitutes any unpaid CHEMCO Group Tax
Liability with respect to taxable periods beginning on or after January 1, 2001.

                  b.    Parent and Holdings each agrees, jointly and severally,
to indemnify the CHEMCO Group and each member thereof for the amount of any tax
paid by the CHEMCO Group or any member thereof with respect to taxable periods
beginning


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on or after January 1, 2001 that is in excess of the amount which constitutes
any CHEMCO Group Tax Liability.

                  c.    Parent and Holdings each agrees, jointly and severally,
to indemnify the CHEMCO Group and each member thereof for one hundred percent
(100%) of any tax paid by the CHEMCO Group or any member thereof with respect to
any taxable period by reason of a decision in or settlement of the R.P. Tax
Case.

                  d.    Any indemnity payable pursuant to paragraph 13(a), 13(b)
or 13(c) hereof shall be payable on demand by the indemnitor(s) immediately
after the indemnitee pays such indemnified liability and provides proof of
payment to the indemnitor.

                  If an indemnity is not paid within five (5) business days
following a demand, the amount owed shall bear interest at the Base Rate plus
two (2) percentage points.

            14.   MISCELLANEOUS PROVISIONS

                  a.    This Agreement contains the entire understanding of the
parties hereto with respect to the subject matter contained herein. No
alteration, amendment or modification of any of the terms of this Agreement
shall be valid unless made by an instrument signed in writing by an authorized
officer of each party.

                  b.    This Agreement has been made in and shall be construed
and enforced in accordance with the laws of the State of Delaware from time to
time obtaining.

                  c.    This Agreement shall be binding upon and inure to the
benefit of each party hereto and its respective successors and assigns.


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                  d.    All notices and other communications hereunder shall be
deemed to have been duly given if delivered by hand or mailed, certified or
registered mail, with postage prepaid addressed to the party to which the notice
or other communication is given at 1361 Alps Road, Wayne, New Jersey 07470.

                  e.    This Agreement may be executed simultaneously 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.

                  f.    The headings of the paragraphs of this Agreement are
inserted for convenience only and shall not constitute a part hereof.

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


                              INTERNATIONAL SPECIALTY PRODUCTS
                              INC.

                              By:   /s/ Richard A. Weinberg
                                  --------------------------
                              Its:
                                  --------------------------

                              NEWCO HOLDINGS INC.

                              By:   /s/ Richard A. Weinberg
                                  --------------------------
                              Its:
                                  --------------------------

                              ISP CHEMCO INC.

                              By:   /s/ Richard A. Weinberg
                                  --------------------------
                              Its:
                                  --------------------------


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