Internal Revenue Bulletin 2025-34 (PDF rendition): IRS Notices

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Bulletin No. 2025–34
August 18, 2025
HIGHLIGHTS
OF THIS ISSUE
These synopses are intended only as aids to the reader in
identifying the subject matter covered. They may not be
relied upon as authoritative interpretations.
ADMINISTRATIVE, INCOME TAX
Notice 2025-28, page 316.
This Notice informs taxpayers of the intention of the Depart-
ment of the Treasury and the Internal Revenue Service to par-
tially withdraw proposed regulations and issue revised pro-
posed regulations regarding the application of the Corporate
Alternative Minimum Tax (CAMT) to applicable corporations
with financial statement income (FSI) attributable to invest-
ments in partnerships. In addition, the notice provides interim
guidance primarily on simplified methods to determine an
applicable corporation’s adjusted financial statement income
(AFSI) with respect to an investment in a partnership, report-
ing by partnerships of information needed to compute ASFI,
and rules for partnership contributions and distributions.
EXCISE TAX
Notice 2025-41, page 325.
This Notice of Determinations adds twenty-one chemi-
cal substances to the list of taxable substances under
§ 4672 subject to the tax imposed by § 4671. This
Notice also modifies Notice 2021-66, 2021-52 I.R.B.
901, by correcting the spelling of sodium nitrilotriacetate
monohydrate and by prescribing a tax rate for sodium
nitrilotriacetate monohydrate.
Finding Lists begin on page ii.

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Introduction
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Part I.—1986 Code.
This part includes rulings and decisions based on provisions
of the Internal Revenue Code of 1986.
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August 18, 2025 Bulletin No. 2025–34

Part III
Interim Guidance
Simplifying Application
of the Corporate
Alternative Minimum Tax to
Partnerships
Notice 2025-28
SECTION 1. OVERVIEW
This notice provides interim guidance
to reduce the compliance burdens and
costs associated with applying the corpo-
rate alternative minimum tax (CAMT) to
partnerships and CAMT entity partners.
The Department of the Treasury (Treasury
Department) and the Internal Revenue
Service (IRS) intend to partially with-
draw the CAMT proposed regulations (as
defined in section 2.03 of this notice) and
to issue revised proposed regulations, in
part, to include rules similar to the interim
guidance provided in sections 3 through 7
of this notice regarding the application of
§§ 56A(c)(2)(D) and 56A(c)(15)(B) of the
Internal Revenue Code (Code) to partner-
ship investments (forthcoming proposed
regulations).
1
Taxpayers may rely on the
interim guidance provided in sections 3
through 7 of this notice as described in
section 9 of this notice. Section 8 of this
notice modifies the reliance rules provided
in the CAMT proposed regulations.
SECTION 2. BACKGROUND
.01 CAMT under the Inflation Reduc-
tion Act.
(1) Overview. Section 10101 of Public
Law 117-169, 136 Stat. 1818, 1818-1828
(August 16, 2022), commonly referred to
as the Inflation Reduction Act of 2022,
amended § 55 to impose the CAMT
based on the “adjusted financial statement
income” (AFSI) of an applicable corpo-
ration for taxable years beginning after
December 31, 2022. Section 59(k)(1)
(A) provides that, for purposes of §§ 55
through 59, the term “applicable corpora-
tion” means, with respect to any taxable
year, any corporation (other than an S cor-
poration, a regulated investment company,
or a real estate investment trust) that meets
an average annual AFSI test for one or
more taxable years that (i) are before that
taxable year and (ii) end after December
31, 2021.
(2) AFSI under § 56A.
(a) General definition of AFSI. For pur-
poses of §§ 55 through 59, the term AFSI
means, with respect to any corporation for
any taxable year, the net income or loss
of the taxpayer set forth on the taxpayer’s
applicable financial statement (AFS) for
that taxable year, adjusted as provided in
§ 56A. See § 56A(a). Section 56A(c) pro-
vides general adjustments to be made to
AFSI. Section 56A(c)(2) provides special
rules that take into account the relation-
ship between entities.
(b) AFSI of partners and partnerships.
Section 56A(c)(2)(D)(i) provides that,
except as provided by the Secretary of
the Treasury or the Secretary’s delegate
(Secretary), if the taxpayer is a partner in
a partnership, the taxpayer’s AFSI with
respect to such partnership is adjusted to
take into account only the taxpayer’s dis-
tributive share of such partnership’s AFSI.
Section 56A(c)(2)(D)(ii) provides that, for
purposes of §§ 55 through 59, the AFSI
of a partnership is the partnership’s net
income or loss set forth on that partner-
ship’s AFS (adjusted under rules similar to
the rules set forth in § 56A).
(3) Authority of the Secretary to provide
necessary adjustments. Section 56A(c)
(15) authorizes the Secretary to issue reg-
ulations or other guidance to provide for
such adjustments to AFSI as the Secretary
determines necessary to carry out the pur-
poses of § 56A, including adjustments to
AFSI (i) to prevent the omission or dupli-
cation of any item, and (ii) to carry out
the principles of part II of subchapter K
of chapter 1 of the Code (subchapter K),
relating to partnership contributions and
distributions.
(4) General authority of the Secretary.
Section 56A(e) authorizes the Secretary
to provide such regulations and other
guidance as necessary to carry out the
purposes of § 56A, including regulations
and other guidance relating to the effect
of the rules of § 56A on partnerships with
income taken into account by an applica-
ble corporation.
.02 Notice 2023-7. On January 17,
2023, the Treasury Department and the
IRS published Notice 2023-7, 2023-3
I.R.B. 390, which announced the intention
of the Treasury Department and the IRS to
issue proposed regulations addressing the
application of the CAMT. Notice 2023-7
provides interim guidance on certain
issues relating to the CAMT, including
issues regarding contributions to, and dis-
tributions from, partnerships, referred to
as “partnership contributions and distribu-
tions” in this notice. Notice 2023-7 stated
that taxpayers may rely on the guidance
provided in Notice 2023-7 until the issu-
ance of the CAMT proposed regulations.
.03 CAMT Proposed Regulations.
(1) Summary. On September 13, 2024,
the Treasury Department and the IRS pub-
lished a notice of proposed rulemaking
(REG-112129-23) in the Federal Register
(89 F.R. 75062) referred to as the “CAMT
proposed regulations” in this notice. The
CAMT proposed regulations addressed
the application of the CAMT and permit
taxpayers to rely on the proposed regula-
tions subject to certain conditions and lim-
itations. On December 26, 2024, the Trea-
sury Department and the IRS published
in the Federal Register (89 F.R. 104909)
technical corrections to the CAMT pro-
posed regulations. The CAMT proposed
regulations generally would provide that
the AFSI of a CAMT entity partner
2
with
respect to its partnership investment is
adjusted as required under the distributive
share provisions in proposed § 1.56A-5 and
by the rules for partnership contributions
and distributions in proposed § 1.56A-20.
Numerous comments were submitted in
response to the CAMT proposed regula-
1
Unless otherwise specified, all “section” or “§” references are to sections of the Code or the Income Tax Regulations (26 CFR part 1). Additionally, unless otherwise specified, terms used in
this notice have the same meaning as in the CAMT proposed regulations.
2
Proposed § 1.56A-1(b)(8) would define “CAMT entity” as any entity identified in § 7701 and the regulations under § 7701 other than a disregarded entity. Proposed § 1.56A-5(e)(4) would
define “CAMT entity partner” as any CAMT entity that is a partner in a partnership.
August 18, 2025 316 Bulletin No. 2025–34

tions, which the Treasury Department and
the IRS continue to consider and study.
Section 2.03(2) of this notice discusses
the provisions of proposed § 1.56A-5,
section 2.03(3) of this notice discusses the
provisions of proposed § 1.56A-20, and
section 2.03(4) of this notice provides a
brief discussion of comments received on
the CAMT proposed regulations.
(2) AFSI adjustments to partner’s dis-
tributive share of partnership AFSI in
proposed § 1.56A-5. Proposed § 1.56A-5
would require application of a bottom-up
approach to determine a partner’s distrib-
utive share of partnership AFSI for pur-
poses of § 56A(c)(2)(D). Under the appli-
cable method in proposed § 1.56A-5(c),
a CAMT entity partner would generally
compute its distributive share of AFSI
with respect to a partnership investment
by, first, disregarding any amount the
CAMT entity partner reflects in its finan-
cial statement income as defined in pro-
posed § 1.56A-1(b)(20) (FSI) with respect
to that investment for the taxable year and,
second, including its “distributive share
amount.”
Pursuant to proposed § 1.56A-5(e), a
CAMT entity partner’s distributive share
amount for each taxable year would be
calculated under a bottom-up method
based on the following four steps: (1) the
CAMT entity partner determines its “dis-
tributive share percentage”; (2) the part-
nership determines its “modified FSI”;
(3) the CAMT entity partner multiplies its
distributive share percentage by the modi-
fied FSI of the partnership (as reported by
the partnership); and (4) the CAMT entity
partner adjusts the product of the amount
determined in step (3) for certain separate-
ly-stated § 56A adjustments.
Proposed § 1.56A-5(e)(2) generally
would provide that a CAMT entity part-
ner’s distributive share percentage is a
fraction, the numerator of which is the
FSI amount that is disregarded under the
applicable method, and the denomina-
tor of which depends on the method of
accounting the CAMT entity partner uses
for AFS purposes, but in each case, as
determined by the CAMT entity partner
for AFS purposes.
Proposed § 1.56A-5(e)(3) generally
would provide that a partnership’s modi-
fied FSI is equal to the partnership’s FSI
for the taxable year, adjusted for all rel-
evant AFSI adjustments provided in the
§ 56A regulations (that is, those AFSI
adjustments that can apply to partner-
ships), with certain enumerated excep-
tions.
Proposed § 1.56A-5(e)(4)(iii) gener-
ally would require the partnership to sep-
arately state certain AFSI items that are
not taken into account as adjustments to a
CAMT entity partner’s distributive share
amount. Instead, these AFSI items would
be directly taken into account by a CAMT
entity partner in determining its AFSI.
These AFSI items include items described
in proposed §§ 1.56A-4(c)(1)(ii) and
1.56A-6(c)(2)(iii) with respect to stock of
foreign corporations owned by the part-
nership and items described in proposed
§ 1.56A-8(c) with respect to creditable
foreign tax expenditures of a partnership.
In a tiered-partnership structure, the
CAMT proposed regulations would
require each partnership, starting with the
lowest-tier partnership and continuing up
the chain of ownership, to use the appli-
cable method to determine the distributive
share amounts of each CAMT entity part-
ner in the tiered-partnership chain.
Under proposed § 1.56A-5(d), a CAMT
entity partner would not be permitted to
disregard any FSI amounts attributable to
a transfer, sale or exchange, contribution,
distribution, dilution, deconsolidation,
change in ownership, or any other transac-
tion between any partners (including the
CAMT entity partner) and the partnership,
or between any partners (including the
CAMT entity partner), that are not derived
from, and included in, the partnership’s
FSI. As a result, such amounts would not
be excluded from a CAMT entity part-
ner’s AFSI under the applicable method.
However, these amounts may be subject
to adjustment under proposed §§ 1.56A-
1(d)(4) (concerning redetermination of
FSI gains and losses) and 1.56A-20 (con-
cerning AFSI adjustments to apply certain
principles of subchapter K).
(3) AFSI adjustments to apply cer-
tain subchapter K principles in proposed
§ 1.56A-20. Proposed § 1.56A-20 would
provide rules for computing AFSI result-
ing from partnership contributions and
distributions (except for certain contribu-
tions or distributions of stock of a foreign
corporation). Proposed § 1.56A-20(b)
would provide a general operating rule
for transactions between a CAMT entity
partner and a partnership in which it holds
an investment. Generally, this rule would
require each CAMT entity partner and the
partnership itself to include in its AFSI any
income, expense, gain, or loss reflected
in its FSI as a result of the transaction,
except as otherwise provided in proposed
§ 1.56A-20. In certain circumstances, pro-
posed § 1.56A-20 would allow deferred
recognition of FSI resulting from part-
nership contributions and distributions to
more closely align with the general princi-
ples of subchapter K.
(a) Contributions of property. Proposed
§ 1.56A-20 would adopt an approach
under which, if property is contributed
by a CAMT entity partner (contributor)
to a partnership in a transaction to which
§ 721(a) applies, any gain or loss reflected
in the contributor’s FSI from the property
transfer would be deferred by the con-
tributor and included in its AFSI ratably,
on a monthly basis, over an applicable
recovery period that would depend on the
type of property contributed (deferred sale
approach). The deferred sale approach
would not apply to disregard any other
FSI amount resulting to the contributor or
the partnership from the transaction (for
example, FSI gain or loss resulting from a
deconsolidation or a dilution) for purposes
of determining AFSI.
Under proposed § 1.56A-20(c)(2),
a contributor would accelerate a por-
tion of its deferred sale gain or loss into
its AFSI upon the occurrence of certain
events, including if a contributor’s distrib-
utive share percentage in the partnership
decreases by more than one-third or if the
partnership disposes of the deferred sale
property.
Proposed § 1.56A-20(c)(3) would
also provide guidance on the determina-
tion of CAMT basis.
3
The partnership’s
initial CAMT basis in contributed prop-
erty would be the partnership’s initial
AFS basis in the contributed property at
the time of contribution, regardless of
whether § 721(a) applies, in whole or in
part, to the contribution. Upon a contri-
3
Proposed § 1.56A-1(b)(7) would define “CAMT basis” as the basis of an item for purposes of determining AFSI.
Bulletin No. 2025–34 317 August 18, 2025

August 18, 2025 318 Bulletin No. 2025–34
bution of property to the partnership to
which § 721(a) applies, the contributor’s
initial CAMT basis in its partnership
investment would be the contributor’s
AFS basis in the acquired partnership
investment, decreased by any deferred
sale gain or increased by any deferred sale
loss that is required to be included in the
contributor’s AFSI under the deferred sale
approach. The contributor’s initial CAMT
basis in the acquired partnership invest-
ment would be subsequently increased or
decreased as the deferred sale gain or loss
is included in its AFSI under the deferred
sale approach.
(b) Distributions of property. Proposed
§ 1.56A-20(d) would adopt a deferred dis-
tribution gain or loss approach, similar to
the rules for contributions of property, for
any gain or loss reflected in a partnership’s
FSI (deferred distribution gain or loss) as
the result of a distribution of property
(deferred distribution property) to which
§ 731(b) applies. Deferred distribution
gain or loss would be (i) allocated among
the partners in proportion to their distrib-
utive share percentages and (ii) included
by the partners in their respective distrib-
utive share amounts ratably, on a monthly
basis, over an applicable recovery period
that would depend on the type of property
distributed.
(c) Treatment of liabilities. Proposed
§ 1.56A-20(e) generally would provide
that the treatment of partner and partner-
ship liabilities for purposes of determin-
ing a CAMT entity partner’s or partner-
ship’s AFSI is based on the treatment of
such liabilities for AFS purposes and not
on the treatment of such liabilities under
§ 752. Regarding the treatment of liabil-
ities upon a contribution or distribution
of property to or from a partnership, the
CAMT proposed regulations would pro-
vide that § 752 is inapplicable in deter-
mining the amount of gain or loss to be
included in the AFSI of the CAMT entity
partner or partnership. Accordingly, any
rules relating to liabilities for regular tax
purposes, such as those under §§ 1.707-5
and 1.707-6, would not apply for purposes
of the CAMT.
(4) Comments received on the part-
nership provisions of the CAMT proposed
regulations.
(a) Comments on the partnership dis-
tributive share rules of proposed § 1.56A-
5. Comments submitted in response
to proposed § 1.56A-5 have generally
requested that alternative methods be
provided for computing a CAMT entity
partner’s distributive share of partner-
ship AFSI, including an elective method
based on the amount of FSI a CAMT
entity partner reports for AFS purposes
with respect to its partnership investment,
additional methods to determine a part-
ner’s distributive share percentage, and an
elective taxable-income exception allow-
able under certain fact patterns. The com-
ments generally provide that the rules in
proposed § 1.56A-5 are unduly complex
and burdensome. A number of comments
requested that interim guidance be pro-
vided regarding the determination of a
CAMT entity partner’s AFSI with respect
to a partnership investment.
(b) Comments on the partnership con-
tribution and distribution rules of pro-
posed § 1.56A-20. Comments submitted
in response to proposed § 1.56A-20 have
generally requested either that changes be
made to the deferred sale approach and the
deferred distribution gain or loss approach
or that different approaches be permitted.
Some comments have requested modifica-
tions to proposed § 1.56A-20 to account
for the inclusion of partnership liabilities
when calculating the amount of AFSI
resulting from partnership contributions
and distributions, to remove AFSI inclu-
sions resulting from certain transactions,
and to modify the acceleration events and
the applicable recovery periods. Addi-
tionally, other comments have requested
allowing for the use of additional sub-
chapter K provisions to account for part-
nership contributions and distributions.
SECTION 3. TOP-DOWN ELECTION
.01 Purpose. The Treasury Department
and the IRS anticipate that the forthcom-
ing proposed regulations will include
modifications to proposed §§ 1.56A-5
and 1.56A-20 consistent with the guid-
ance provided in this section 3 to allow
a CAMT entity partner to make a “top-
down election” to elect to determine its
amount of AFSI from a partnership invest-
ment for each taxable year (starting with
the first taxable year for which the election
is in effect) by reference to the amount the
CAMT entity partner reflects in its FSI for
the taxable year with respect to the part-
nership investment.
.02 Effect of Top-Down Election.
(1) General calculation of AFSI for a
partnership investment. If a CAMT entity
partner has a top-down election in effect
with respect to a partnership investment,
the CAMT entity partner’s AFSI for such
partnership investment is the sum of (i)
80 percent of the top-down amount (as
defined in section 3.02(2) of this notice),
(ii) amounts included in AFSI from a sale
or exchange of the partnership invest-
ment as described in section 3.02(3) of
this notice, and (iii) the AFSI adjustments
described in section 3.02(4) of this notice.
Except as provided in this section 3.02, the
CAMT entity partner does not adjust its
AFSI for such partnership investment by
making any other adjustments provided
in § 56A and the CAMT proposed regula-
tions (such as the AFSI adjustments in pro-
posed § 1.56A-15 applicable to “property
to which section 168 applies,” as defined
in proposed § 1.56A-15(c)). For purposes
of applying the rules of proposed § 1.56A-
5, 80 percent of the top-down amount will
be treated as the CAMT entity partner’s
distributive share amount. Thus, under
proposed § 1.56A-5(j)(1), if 80 percent of
the top-down amount is a negative num-
ber, the CAMT entity partner includes
such amount in its AFSI for the taxable
year only to the extent that such negative
amount does not exceed the CAMT entity
partner’s CAMT basis in its partnership
investment. Under proposed § 1.56A-5(j)
(3), the CAMT entity partner’s CAMT
basis in its partnership investment must
be increased or decreased (as applicable),
but not below zero pursuant to proposed
§ 1.56A-5(j), by 80 percent of the top-
down amount and, to the extent provided
by the CAMT proposed regulations, the
AFSI adjustments described in section
3.02(4) of this notice.
(2) Top-down amount.
(a) Inclusions. Except as provided
in section 3.02(2)(b) of this notice, the
top-down amount equals any amounts
reflected in the CAMT entity partner’s FSI
for the taxable year that are attributable to
the partnership investment for which the
top-down election is in effect, including
FSI amounts attributable to a contribu-
tion of property to the partnership by the
CAMT entity partner or a distribution of

Bulletin No. 2025–34 319 August 18, 2025
property by the partnership to the CAMT
entity partner. Thus, the CAMT entity
partner may not apply § 721, § 731, the
rules in section 3 of Notice 2023-7, the
rules in proposed § 1.56A-20, or the rules
in section 6 of this notice to defer inclu-
sion of FSI amounts attributable to a con-
tribution of property to the partnership by
the CAMT entity partner or a distribution
of property by the partnership.
(b) Exclusions.
(i) The top-down amount excludes
any FSI amounts attributable to a sale or
exchange of all or a portion of the CAMT
entity partner’s partnership investment
(including a sale or exchange under
§ 731(a)) in a transaction that is not a
nonrecognition transaction for regular tax
purposes (recognition transaction). See
section 3.02(3) of this notice, under which
100 percent of such FSI amounts gener-
ally are included in AFSI.
(ii) The top-down amount excludes
any FSI or AFSI amounts described in
proposed §§ 1.56A-4(c)(1)(i) and (ii),
1.56A-6(c)(2)(iii), or 1.56A-8(b) and (c).
See section 3.02(4) of this notice, which
instructs how such amounts should be
taken into account by a CAMT entity part-
ner in computing its AFSI with respect to
a partnership investment for which a top-
down election is in effect.
(iii) The top-down amount excludes
any specified non-realization amounts to
the extent excluded under section 7 of this
notice.
(3) AFSI upon sale or exchange of
partnership investment. If a CAMT entity
partner sells or exchanges all or a portion
of its partnership investment (including
a sale or exchange under § 731(a)) in a
recognition transaction, the CAMT entity
partner determines the attributable AFSI
using CAMT basis and includes such
amount in its AFSI for the taxable year of
the sale or exchange.
(4) Certain adjustments for foreign
stock. If a CAMT entity partner has a top-
down election in effect with respect to a
partnership investment, in determining
the CAMT entity partner’s AFSI for the
taxable year with respect to its partner-
ship investment, the FSI items described
in proposed §§ 1.56A-4(c)(1)(i) and
1.56A-8(b) are disregarded and the items
described in proposed §§ 1.56A-4(c)(1)
(ii), 1.56A-6(c)(2)(iii), and 1.56A-8(c) are
included in AFSI as provided in proposed
§ 1.56A-5(e)(4)(iii)(A) through (C).
(5) Effect on a partnership. If a CAMT
entity partner has a top-down election in
effect with respect to a partnership invest-
ment, the partnership is not required to
report its modified FSI to such CAMT
entity partner. However, the partnership is
required to compute and report its modi-
fied FSI to another CAMT entity partner
if notice is provided to the partnership that
such other CAMT entity partner requires
the partnership to compute and report its
modified FSI. If a partnership computes
or reports modified FSI (or other CAMT
amounts) for a CAMT entity partner for
a taxable year in which the CAMT entity
partner has a top-down election in effect
for such partnership investment, the
CAMT entity partner must continue to
apply the top-down election with respect
to such partnership investment in accor-
dance with section 3.05 of this notice.
.03 Eligibility to Make Top-Down
Election. Any CAMT entity partner other
than a partnership may make a top-down
election with respect to one or more part-
nerships in which it is a direct partner for
Federal income tax purposes. If a CAMT
entity partner is a direct partner in multi-
ple partnerships, it may make a top-down
election with respect to its investments in
some partnerships and not its investments
in other partnerships. A top-down elec-
tion may not be made with respect to an
investment other than an investment in a
partnership.
.04 Manner of Making Top-Down Elec-
tion.
(1) In general. Except as provided in
section 3.04(2) of this notice, a CAMT
entity partner makes a top-down election
by attaching a statement to its Federal
income tax return for the taxable year. The
statement must be titled “Top-Down Elec-
tion for CAMT” and include the CAMT
entity partner’s name, address, taxpayer
identification number, a statement that
the CAMT entity partner is making a top-
down election under Notice 2025-28, and
the name and taxpayer identification num-
ber (if applicable) of each partnership for
which the CAMT entity partner is making
a top-down election.
(2) CFCs. In the case of a CAMT
entity partner that is a controlled for-
eign corporation (as defined in § 957 or,
if applicable, § 953(c)(1)(B)) (CFC), the
controlling domestic shareholders (as
defined in § 1.964-1(c)(5)) of the CFC
make a top-down election on behalf of the
CFC in accordance with the procedures
set forth in § 1.964-1(c)(3). The statement
described in § 1.964-1(c)(3)(ii) must be
titled “Top-Down Election for CAMT on
Behalf of CFC” and, in addition to the
information set forth in § 1.964-1(c)(3)(ii),
must include a statement that the CFC is
making a top-down election under Notice
2025-28 and the names and taxpayer iden-
tification number (if applicable) of each
partnership for which the CFC is making
a top-down election. A top-down election
made on behalf of a CFC is binding on all
United States shareholders (as defined in
§ 951(b) or, if applicable, § 953(c)(1)(A))
of the CFC.
.05 Duration of Top-Down Election.
Once made, a top-down election continues
in effect for all subsequent taxable years
beginning before the issuance of the forth-
coming proposed regulations.
SECTION 4. LIMITED TAXABLE-
INCOME ELECTION
.01 Purpose. The Treasury Department
and the IRS anticipate that the forthcom-
ing proposed regulations will include
modifications to proposed §§ 1.56A-5 and
1.56A-20 consistent with the guidance
provided in this section 4 to allow certain
CAMT entity partners to make a “tax-
able-income election” to elect to use tax-
able-income amounts to determine their
AFSI from a partnership investment.
.02 Effect of Taxable-Income Election.
(1) Effect of taxable-income election
by CAMT entity partner. If a CAMT
entity partner has a taxable-income elec-
tion in effect with respect to a partnership
investment for a taxable year, the CAMT
entity partner’s AFSI for the partnership
investment for such taxable year is equal
to the sum of: (i) the CAMT entity part-
ner’s taxable-income amount determined
under section 4.02(2) of this notice, (ii)
AFSI attributable to sales or exchanges
described in section 4.02(3) of this notice,
and (iii) the inclusions in AFSI attribut-
able to adjustments described in section
4.02(4) of this notice. For purposes of
applying the rules of proposed § 1.56A-5,
the taxable-income amount will be treated

August 18, 2025 320 Bulletin No. 2025–34
as the CAMT entity partner’s distribu-
tive share amount. Thus, under proposed
§ 1.56A-5(j)(1), if the taxable-income
amount is a negative number, the CAMT
entity partner includes such amount in
its AFSI for the taxable year only to the
extent that such negative amount does not
exceed the CAMT entity partner’s CAMT
basis in its partnership investment. Under
proposed § 1.56A-5(j)(3), the CAMT
entity partner’s CAMT basis in its part-
nership investment must be increased or
decreased (as applicable), but not below
zero pursuant to proposed § 1.56A-5(j),
by the taxable-income amount, and, to
the extent provided by the CAMT pro-
posed regulations, the AFSI adjustments
described in section 4.02(4) of this notice.
(2) CAMT entity partner’s taxable-in-
come amount. A CAMT entity partner’s
taxable-income amount from a partner-
ship investment includes the sum of the
CAMT entity partner’s distributive share
of income, gain, loss, and deduction from
the partnership investment for regular
tax purposes, based on application of all
applicable regular tax rules (for example,
§ 704(c) and (d)), to the extent included in
the CAMT entity partner’s taxable income,
but excluding any amounts described in
proposed §§ 1.56A-4(c)(1)(ii), 1.56A-6(c)
(2)(iii), or 1.56A-8(c). Additionally, in lieu
of applying the rules of section 3 of Notice
2023-7, proposed § 1.56A-20, or any
rules in section 6 of this notice, a CAMT
entity partner’s taxable-income amount
with respect to a partnership investment
includes any income, gain, loss, or deduc-
tion resulting from partnership contribu-
tions and distributions as computed for
regular tax purposes. See section 7 of this
notice regarding the treatment of certain
transactions.
(3) Certain sales or exchanges. If a
CAMT entity partner with a taxable-in-
come election in effect with respect to
a partnership receives a distribution of
property from the partnership in a trans-
action that is a nonrecognition transaction
for regular tax purposes, the CAMT entity
partner’s initial CAMT basis upon receipt
of the distributed property is its adjusted
basis for regular tax purposes. Following
the distribution, the CAMT entity part-
ner’s CAMT basis in the distributed prop-
erty must be adjusted in accordance with
the rules of the CAMT proposed regula-
tions. Thus, if the CAMT entity partner
subsequently disposes of the distributed
property, any AFSI attributable to such
disposition must be determined using that
CAMT basis and included in the CAMT
entity partner’s AFSI. If a CAMT entity
partner with a taxable-income election in
effect with respect to a partnership invest-
ment sells or exchanges all or a portion
of its partnership investment (including
a sale or exchange under § 731(a)), any
resulting AFSI must be determined using
CAMT basis and included in the CAMT
entity partner’s AFSI. See section 7 of this
notice regarding the treatment of certain
transactions.
(4) Certain adjustments for foreign
stock. If a CAMT entity partner has a tax-
able-income election in effect with respect
to a partnership investment, in determin-
ing the CAMT entity partner’s AFSI for
the taxable year with respect to its partner-
ship investment, the FSI items described
in proposed §§ 1.56A-4(c)(1)(i) and
1.56A-8(b) are disregarded and the items
described in proposed §§ 1.56A-4(c)(1)
(ii), 1.56A-6(c)(2)(iii), and 1.56A-8(c) are
included in AFSI as provided in proposed
§ 1.56A-5(e)(4)(iii)(A) through (C).
(5) Effect on a partnership of a CAMT
entity partner’s taxable-income election.
If a CAMT entity partner has a taxable-in-
come election in effect with respect to a
partnership investment, the partnership is
not required to report its modified FSI to
such CAMT entity partner. However, the
partnership is required to compute and
report its modified FSI to another CAMT
entity partner if notice is provided to the
partnership that such other CAMT entity
partner requires the partnership to com-
pute and report its modified FSI. If a part-
nership computes or reports modified FSI
(or other CAMT amounts) for a CAMT
entity partner for a taxable year for which
the CAMT entity partner has a taxable-in-
come election in effect for such partner-
ship investment, the CAMT entity partner
must continue to apply the taxable-income
election with respect to such partnership
investment in accordance with section
4.05 of this notice.
.03 Eligibility to Make Taxable-Income
Election.
(1) Type of entity. Any CAMT entity
partner other than a partnership may make
a taxable-income election with respect to
a partnership in which it is a direct part-
ner for Federal income tax purposes if, as
of the last day of the taxable year, (i) the
CAMT entity partner’s test group does not
own more than 20 percent of the interests
in capital or profits of the partnership (as
determined under section 4.03(2) of this
notice), and (ii) the fair market value
of such partnership investment held by
the CAMT entity partner’s test group is
$200,000,000 or less (as determined under
section 4.03(2) of this notice).
(2) Test group. For purposes of this
section 4.03, “test group” has the mean-
ing in proposed § 1.59-2(b)(6). The
CAMT entity partner desiring to make a
taxable-income election with respect to a
partnership investment determines its test
group as of the last day of the taxable year.
Accordingly, such test group is comprised
of the CAMT entity partner desiring to
make the taxable-income election and the
CAMT entities required to be aggregated
with such CAMT entity partner under the
relevant relationship criteria as defined in
proposed § 1.59-2(b)(4) as of the last day
of the taxable year. For purposes of sec-
tion 4.03(1)(i) and (ii) of this notice, the
CAMT entity partner’s test group’s inter-
ests in capital or profits of the partnership,
or the fair market value of the investments
in the partnership held by the CAMT entity
partner’s test group, as applicable, is the
sum of each test group member’s interest
in the capital or profits of the partnership,
or the sum of the fair market value of each
investment in the partnership held by each
member of the CAMT entity partner’s test
group, as applicable, as of the last day of
the taxable year.
(3) Investments in multiple partner-
ships. If a CAMT entity partner has
investments in multiple partnerships that
qualify for the taxable-income election,
it may make a taxable-income election
with respect to its investments in some
partnerships and not to its investments in
other partnerships. A taxable-income elec-
tion may not be made with respect to an
investment other than an investment in a
partnership.
.04 Manner of Making Taxable-Income
Election.
(1) In general. Except as provided in
section 4.04(2) of this notice, an eligible
CAMT entity partner makes a taxable-in-
come election by attaching a statement to

Bulletin No. 2025–34 321 August 18, 2025
its Federal income tax return for the tax-
able year in which the election is made.
The statement must be titled “Taxable-In-
come Election for CAMT” and include
the CAMT entity partner’s name, address,
taxpayer identification number, a state-
ment that the CAMT entity partner is
making a taxable-income election under
Notice 2025-28, and the name and tax-
payer identification number (if applicable)
of each partnership for which the CAMT
entity partner makes a taxable-income
election.
(2) CFCs. In the case of an eligible
CAMT entity partner that is a CFC, the
controlling domestic shareholders of the
CFC make a taxable-income election on
behalf of the CFC in accordance with the
procedures set forth in § 1.964-1(c)(3).
The statement described in § 1.964-1(c)
(3)(ii) must be titled “Taxable-Income
Election for CAMT on Behalf of CFC”
and, in addition to the information set
forth in § 1.964-1(c)(3)(ii), must include
a statement that the CFC is making a
taxable-income election under Notice
2025-28 and the name and taxpayer iden-
tification number (if applicable) of each
partnership for which the CFC is making
a taxable-income election. A taxable-in-
come election made on behalf of a CFC
is binding on all United States sharehold-
ers of the CFC.
.05 Duration of Taxable-Income Elec-
tion. Once made, a taxable-income elec-
tion continues in effect for all subsequent
taxable years beginning before the issu-
ance of the forthcoming proposed regu-
lations unless the CAMT entity partner
no longer meets the eligibility require-
ments for making a taxable-income elec-
tion under section 4.03 of this notice. If
on the last day of the taxable year the
CAMT entity partner no longer meets the
eligibility requirements for making the
taxable-income election, the election will
terminate for that taxable year and any
subsequent taxable year, and the CAMT
entity partner will not be allowed to make
a subsequent taxable-income election with
respect to the partnership. For the taxable
year in which the taxable-income election
ceases to be in effect, the CAMT entity
partner must attach a statement to its Fed-
eral income tax return disclosing the rea-
sons for the termination of the taxable-in-
come election.
SECTION 5. REASONABLE METHOD
TO DETERMINE PARTNERS’
DISTRIBUTIVE SHARES OF
MODIFIED FSI AND REPORTING
REQUIREMENT MODIFICATIONS
.01 Purpose. The Treasury Department
and the IRS anticipate that the forthcom-
ing proposed regulations will modify pro-
posed § 1.56A-5 consistent with the guid-
ance provided in this section 5 to allow
partnerships to use any reasonable method
to determine a CAMT entity partner’s dis-
tributive share. In addition, the forthcom-
ing proposed regulations will modify cer-
tain reporting requirements in proposed
§ 1.56A-5.
.02 Reasonable Method to Deter-
mine CAMT Entity Partners’ Distributive
Shares of Modified FSI.
(1) Partnership determination. Follow-
ing the determination of modified FSI pur-
suant to proposed § 1.56A-5(e)(3), a part-
nership may determine a CAMT entity
partner’s distributive share of such mod-
ified FSI using any reasonable method,
provided that it uses the same method
for all CAMT entity partners in the part-
nership. If a partnership determines any
CAMT entity partner’s distributive share
of modified FSI in accordance with the
rules of this section 5.02, the partnership
must report to each CAMT entity partner
its distributive share amount for the tax-
able year pursuant to section 5.04(2) of
this notice; however, the partnership need
not report distributive share amounts to a
CAMT entity partner that has a top-down
election or taxable-income election in
effect with respect to the partnership. In
the case of a CAMT entity partner that
has a top-down or taxable-income elec-
tion in effect with respect to a partnership
investment, if the partnership computes
or reports modified FSI (or other CAMT
amount) for the CAMT entity partner,
the CAMT entity partner must continue
to apply the top-down or taxable-income
election with respect to such partnership
investment in accordance with section
3.05 or 4.05 of this notice.
(2) Reasonable methods. A reason-
able method must be consistent with the
purposes of § 56A. A reasonable method
does not include a method that results in
the partnership allocating more than, or
less than, all of its modified FSI among its
partners, or a method undertaken with a
principal purpose of avoiding applicable
corporation status or reducing or avoiding
a CAMT liability under § 55. A reasonable
method includes a method that determines
a CAMT entity partner’s distributive share
of modified FSI for a taxable year based
on:
(a) The partner’s relative share of “net
§ 704(b) income or loss” (meaning, if the
partnership has net income attributable to
§ 704(b) items, such net income, and if
the partnership has overall net loss attrib-
utable to § 704(b) items, such net loss) for
such taxable year. The determination of
the partnership’s net § 704(b) income or
loss would disregard § 704(c) and its prin-
ciples, and “regulatory allocations” such
as those described in § 1.721(c)-1(b)(10).
If the partnership makes a guaranteed pay-
ment within the meaning of § 707(c) that
is deductible for regular tax purposes, then
solely for purposes of this section 5.02(2)
(a), such guaranteed payment is treated as
a share of net § 704(b) income; or
(b) The provisions in the partner-
ship agreement that the partnership uses
to allocate net § 704(b) income or loss
for the entire taxable year, provided the
partnership’s allocations of net § 704(b)
income or loss comply with § 704(b). If
the partnership makes a guaranteed pay-
ment within the meaning of § 707(c) that is
deductible for regular tax purposes, solely
for purposes of this section 5.02(2)(b), the
provisions of the partnership agreement
that the partnership uses to allocate net
§ 704(b) income or loss are considered to
include the provisions of the partnership
agreement relating to such guaranteed
payment.
(3) Effect of a partnership determina-
tion. A partnership that applies proposed
§ 1.56A-20, including with any of the
modifications described in section 6.03 of
this notice, must use the same method to
determine a partner’s distributive share of
deferred distribution gain or loss as it uses
to determine a partner’s distributive share
of modified FSI.
.03 Selection and Duration of Method.
A partnership chooses a reasonable
method under this section 5 by attach-
ing a statement to its Federal income or
information return for the taxable year.
The statement must be titled “Reason-
able Allocation Method for CAMT” and

August 18, 2025 322 Bulletin No. 2025–34
include the partnership’s name, address,
taxpayer identification number, a state-
ment that the partnership is applying a rea-
sonable method under section 5 of Notice
2025-28 and a description of the reason-
able method. Once a partnership has cho-
sen a reasonable method under this sec-
tion 5, the partnership must consistently
apply the method for all subsequent tax-
able years beginning before the issuance
of the forthcoming proposed regulations.
.04 Modifications to Certain Reporting
Requirements.
(1) Permissible modifications. A
CAMT entity, including an upper-tier
partnership (UTP), may apply proposed
§ 1.56A-5(h) and (i) with the following
modifications:
(a) Instead of a CAMT entity being
required to request information from a
partnership by the 30th day after the close
of the taxable year of the partnership
pursuant to proposed § 1.56A-5(h)(1), a
CAMT entity may request information
from a partnership up to 60 days before the
due date (with extensions) for the filing of
the partnership’s Federal return of partner-
ship income for such taxable year. In the
case of a partnership that is not required
to file a return under § 1.6031(a)-1(b), the
CAMT entity may request information
from the partnership up to the fifteenth
day of the seventh month after the close
of the taxable year of the partnership (as
determined applying § 706(b));
(b) If a partnership fails to furnish the
information requested by a CAMT entity
as described in proposed § 1.56A-5(h)(2)
(i) then, instead of applying the required
estimate rules under proposed § 1.56A-
5(h)(2)(ii), a CAMT entity may base its
estimate on its books and records and is
not required to continue to use its best
efforts to obtain the requested information
from the partnership; and
(c) Instead of a UTP being required
to request any necessary information by
the later of the 30th day after the close
of the taxable year of the partnership to
which the information request relates or
14 days after the date the UTP receives a
request from another UTP under proposed
§ 1.56A-5(i)(2)(iii), a UTP can request
the information by the later of the 60th
day after the close of the taxable year of
the partnership to which the information
request relates or 30 days after the date
the UTP receives a request from another
UTP (with corresponding changes to pro-
posed § 1.56A-5(i)(3)(ii) relating to late
requests).
(2) Required modification. If a part-
nership determines a CAMT entity part-
ner’s distributive share of modified FSI in
accordance with this section 5 for a tax-
able year, instead of applying the rules of
proposed § 1.56A-5(i)(1)(i) and (ii), the
partnership must report to each CAMT
entity partner for the taxable year the
CAMT entity partner’s distributive share
of the partnership’s modified FSI.
SECTION 6. ADDITIONAL
METHODS TO ACCOUNT FOR
PARTNERSHIP CONTRIBUTIONS
AND DISTRIBUTIONS
.01 Purpose. The Treasury Department
and the IRS anticipate that the forthcoming
proposed regulations will include modifi-
cations to proposed § 1.56A-20 consistent
with the guidance provided in this section
6 to allow CAMT entities to choose from
two additional methods described in sec-
tions 6.02 and 6.03 of this notice to deter-
mine AFSI adjustments for partnership
contributions and distributions. However,
these additional methods do not apply to
partnership contributions and distribu-
tions involving stock of a foreign corpora-
tion. See proposed § 1.56A-4(c) for rules
that apply to partnership contributions and
distributions involving stock of a foreign
corporation.
.02 Modified -20 Method. A CAMT
entity partner may choose to apply pro-
posed § 1.56A-20 with the modifications
described in section 6.02(1)(a) through
(h) of this notice (modified -20 method)
rather than the corresponding rules in pro-
posed § 1.56A-20.
(1) Effect of choosing modified -20
method.
(a) In lieu of the liability allocation
rules under proposed § 1.56A-20(e)(2),
the rules of § 752 and the rules under
§§ 1.707-4, 1.707-5 and 1.707-6 apply to
determine whether § 721(a) or § 731(b)
apply to partnership contributions and dis-
tributions of property subject to liabilities;
(b) In lieu of the applicable recovery
period rules of proposed § 1.56A-20(c)
(2)(i)(B) through (E), the applicable
recovery period is 15 years for deferred
sale property that is “property to which
section 168 applies” (as defined in pro-
posed § 1.56A-15(c)), qualified wire-
less spectrum (as defined in proposed
§ 1.56A-16(c)), or subject to depreciation
or amortization for AFS purposes;
(c) In lieu of the recovery period
rules of proposed § 1.56A-20(c)(2)(i)(F),
there is no applicable recovery period for
deferred sale property that is not subject
to depreciation or amortization for AFS
purposes, and no deferred sale gain or loss
is required to be included in a contribu-
tor’s AFSI for such property except in the
case of an event described in proposed
§ 1.56A-20(c)(2)(iii) or (iv) (as modified
by this section 6.02);
(d) Proposed § 1.56A-20(c)(2)(ii) does
not apply, except to the extent the contrib-
utor disposes of its entire investment in
the partnership, including through a liqui-
dating distribution by the partnership;
(e) Proposed § 1.56A-20(c)(2)(iii)
applies only to the extent the partnership
sells, distributes, or otherwise disposes of
the deferred sale property, or any prop-
erty the tax basis of which is determined
in whole or in part by reference to the
adjusted basis of the deferred sale prop-
erty, in a recognition transaction;
(f) In lieu of the recovery period
rules of proposed § 1.56A-20(d)(1)(ii)
(B) through (E), the applicable recovery
period is 15 years for deferred distribution
property that is “property to which sec-
tion 168 applies” (as defined in proposed
§ 1.56A-15(c)), qualified wireless spec-
trum, or subject to depreciation or amor-
tization for AFS purposes;
(g) In lieu of the recovery period rules
of proposed § 1.56A-20(d)(1)(ii)(F),
there is no applicable recovery period for
deferred distribution property that is not
subject to depreciation or amortization for
AFS purposes, and no deferred distribu-
tion gain or loss would be required to be
included in a partner’s distributive share
amount except in the case of an event
described in proposed § 1.56A-20(d)(1)
(iii) or (d)(2)(ii) (as modified by this sec-
tion 6.02); and
(h) Proposed § 1.56A-20(d)(1)(iii)(B)
does not apply.
(2) Method of choosing modified -20
method.
(a) Except as provided in section
6.02(2)(b) of this notice, a CAMT entity

Bulletin No. 2025–34 323 August 18, 2025
partner chooses the modified -20 method
with respect to a partnership investment
by attaching a statement to its Federal
income tax return, income return, or
information return for the taxable year.
The statement must be titled “Modified
-20 Method for CAMT” and include the
CAMT entity partner’s name, address,
taxpayer identification number, a state-
ment that the CAMT entity partner is
choosing the modified -20 method under
section 6.02 of Notice 2025-28, and the
name and taxpayer identification num-
ber (if applicable) of each partnership for
which the CAMT entity partner is choos-
ing the modified -20 method.
(b) CFCs. In the case of an eligible
CAMT entity partner that is a CFC, the
controlling domestic shareholders of the
CFC choose the modified -20 method
on behalf of the CFC in accordance with
the procedures set forth in § 1.964-1(c)
(3). The statement described in § 1.964-
1(c)(3)(ii) must be titled “Modified -20
Method for CAMT on Behalf of CFC”
and, in addition to the information set
forth in § 1.964-1(c)(3)(ii), must include
a statement that the CFC is choosing the
modified -20 method under Notice 2025-
28 and the name and taxpayer identifica-
tion number (if applicable) of each part-
nership for which the CFC is choosing the
modified -20 method. The choice of the
modified -20 method made on behalf of a
CFC is binding on all United States share-
holders of the CFC.
(3) Duration of modified -20 method.
Once a CAMT entity partner has chosen
the modified -20 method, it must con-
sistently apply all of the modifications
under section 6.02(1)(a) through (h) of
this notice to all contributions and distri-
butions for all subsequent taxable years
beginning before the issuance of the forth-
coming proposed regulations.
.03 Full Subchapter K Method. A part-
nership (with the written consent of all
CAMT entity partners that were partners
at any time during the year for which the
full subchapter K method is adopted and
that do not have a top-down or taxable-in-
come election in effect with respect to the
partnership investment) may apply the
principles of §§ 721 and 731 to determine
its partners’ distributive shares of partner-
ship AFSI resulting from partnership con-
tributions and distributions.
(1) Effect of choosing full subchap-
ter K method. Under the full subchapter
K method, the provisions of subchap-
ter K would apply with the partnership
using CAMT inputs (for example, using
CAMT basis for an item of property if the
CAMT basis is different from the regular
tax basis) where appropriate. For exam-
ple, if a partnership applies the principles
of §§ 721 and 731 for partnership contri-
butions and distributions for CAMT pur-
poses, the partnership must also apply the
principles of other relevant provisions in
subchapter K (for example, §§ 704(c),
732, 734, 737) for CAMT purposes.
Additionally, if a partnership adopts the
full subchapter K method described in
this section 6.03, the partnership must
adopt the same relevant methods and
elections for CAMT purposes as it does
for regular tax purposes. For example, if
a partnership adopts the remedial allo-
cation method under § 1.704-3(d) for an
item of property for regular tax purposes,
it must also adopt the remedial alloca-
tion method for such property for CAMT
purposes. Similarly, if a partnership
makes special basis adjustments under
§§ 734(b) or 743(b), it must make cor-
responding basis adjustments for CAMT
purposes.
(2) Method of choosing full subchapter
K method. A partnership chooses the full
subchapter K method by attaching a state-
ment to its Federal income or information
return for the taxable year. The statement
must be titled “Full Subchapter K Method
for CAMT” and include the partnership’s
name, address, taxpayer identification
number, and a statement that the part-
nership is choosing the full subchapter
K method under section 6.03 of Notice
2025-28. The partnership must also main-
tain in its books and records computations
substantiating compliance with the full
subchapter K method.
(3) Duration of full subchapter K
method. Once a partnership has chosen the
full subchapter K method, the partnership
must consistently apply the method to all
contributions and distributions for all sub-
sequent taxable years beginning before
the issuance of the forthcoming proposed
regulations, regardless of whether a new
CAMT entity partner is admitted to the
partnership and does not consent to the
subchapter K method.
SECTION 7. FSI ATTRIBUTABLE TO
CERTAIN TRANSACTIONS
.01 Purpose. The Treasury Department
and the IRS anticipate that the forthcom-
ing proposed regulations will include
modifications to proposed §§ 1.56A-5
and 1.56A-20 consistent with the guid-
ance provided in this section 7 to allow a
CAMT entity partner to:
(1) Disregard in computing AFSI with
respect to a partnership investment any FSI
amounts attributable to a consolidation,
remeasurement, deconsolidation, dilution,
or change in ownership of a partner other
than the CAMT entity partner to the extent
that such transactions are non-realization
events for regular tax purposes, referred to
as “specified non-realization amounts” in
this notice,
4
and
(2) Make appropriate adjustments to
any relevant CAMT attributes to ensure
that the disregarded amounts are not per-
manently eliminated.
.02 AFSI Exclusion. A CAMT entity
partner (including a UTP) may disregard
in computing AFSI any specified non-re-
alization amounts with respect to a part-
nership investment for a taxable year.
.03 Appropriate Adjustments. If a
CAMT entity partner disregards in com-
puting AFSI with respect to a partnership
investment any specified non-realization
amounts under section 7.02 of this notice,
appropriate adjustments must be made to
any relevant CAMT attributes (for exam-
ple, the CAMT basis of the partnership
investment) to reflect that the CAMT
entity partner did not include the speci-
fied non-realization amounts in AFSI with
respect to the partnership investment and
to ensure that the CAMT entity partner’s
AFSI from the partnership investment will
be properly computed.
4
Specified non-realization amounts do not include FSI attributable to a change in the fair value of a partnership investment, such as for a CAMT entity partner that uses the fair value method
of accounting with respect to its partnership investment.

August 18, 2025 324 Bulletin No. 2025–34
SECTION 8. RELIANCE ON
PROPOSED §§ 1.56A-5 AND 1.56A-20.
.01 The Treasury Department and the
IRS anticipate that the forthcoming pro-
posed regulations will provide that, for
taxable years beginning before the appli-
cability date of final regulations address-
ing §§ 56A(c)(2)(D) and 56A(c)(15)(B)
as applied to partnership investments, a
taxpayer may rely on the rules set forth
in proposed § 1.56A-5 (excluding pro-
posed § 1.56A-5(l)(2)(ii) and (iii)), as
contained in the CAMT proposed regu-
lations and without any of the modifica-
tions described in this notice, including
for purposes of filing an amended return
or administrative adjustment request,
if the taxpayer and each member of its
test group determined under proposed
§ 1.59-2 for that taxable year consistently
follow proposed § 1.56A-5 (excluding
proposed § 1.56A-5(l)(2)(ii) and (iii)) in
its entirety, regardless of whether the tax-
payer also relies on proposed § 1.56A-20.
Similarly, for such taxable years, a tax-
payer may rely on proposed § 1.56A-20,
as contained in the CAMT proposed reg-
ulations and without any of the modifica-
tions contained in this notice, including
for purposes of filing an amended return
or administrative adjustment request,
if the taxpayer and each member of its
test group determined under proposed
§ 1.59-2 for that taxable year consistently
follow such section in its entirety, regard-
less of whether the taxpayer also relies
on proposed § 1.56A-5.
.02 In addition, for taxable years
beginning before the date the forthcom-
ing proposed regulations are published
in the Federal Register, a taxpayer may
rely on the rules set forth in proposed
§ 1.56A-5 (excluding proposed § 1.56A-
5(l)(2)(ii) and (iii)), as contained in the
CAMT proposed regulations and without
any of the modifications contained in this
notice, including for purposes of filing an
amended return or administrative adjust-
ment request, if the taxpayer and each
member of its test group determined under
proposed § 1.59-2 for that taxable year
consistently follow proposed § 1.56A-5
in its entirety, regardless of whether the
taxpayer also relies on proposed § 1.56A-
20. Similarly, for such taxable years, a
taxpayer may rely on proposed § 1.56A-
20, as contained in the CAMT proposed
regulations and without any of the modifi-
cations contained in this notice, including
for purposes of filing an amended return
or administrative adjustment request,
if the taxpayer and each member of its
test group determined under proposed
§ 1.59-2 for that taxable year consistently
follow proposed § 1.56A-20 in its entirety,
regardless of whether the taxpayer also
relies on proposed § 1.56A-5.
SECTION 9. APPLICABILITY DATES
It is anticipated that the forthcoming
proposed regulations will provide that
rules consistent with the rules described
in sections 3 through 7 of this notice
apply for taxable years beginning on or
after the date final regulations address-
ing §§ 56A(c)(2)(D) and 56A(c)(15)(B)
as applied to partnership investments are
published in the Federal Register. For
taxable years beginning before the date
on which forthcoming proposed regula-
tions are published in the Federal Reg-
ister or other guidance modifying this
section 9 is published in the Internal Rev-
enue Bulletin, taxpayers may choose to
apply the guidance in sections 3 through
7 of this notice, including for purposes
of filing amended returns or administra-
tive adjustment requests. Thus, for part-
nership contributions and distributions
in taxable years ending on or before the
issuance of the CAMT proposed regula-
tions on September 13, 2024, taxpayers
may rely on the guidance in this notice,
the guidance in Notice 2023-7, or the
CAMT proposed regulations; in each
case, any FSI attributable to a partner-
ship contribution or distribution that is
deferred must eventually be included in
AFSI. A taxpayer’s reliance on any of the
guidance in sections 3 through 7 of this
notice for a taxable year will not cause
the taxpayer to become subject to, or to
violate, the reliance rules, including the
consistency requirements, provided in
the preamble of the CAMT proposed reg-
ulations,
5
for such taxable year.
SECTION 10. PAPERWORK
REDUCTION ACT
The Paperwork Reduction Act of 1995
(44 U.S.C. §§ 3501 - 3520) (PRA) requires
that a Federal agency obtain the approval
of the Office of Management and Bud-
get (OMB) before collecting information
from the public, whether such collection
of information is mandatory, voluntary, or
required to obtain or retain a benefit. An
agency may not conduct or sponsor, and a
person is not required to respond to, a col-
lection of information unless the collec-
tion of information displays a valid OMB
control number.
The collections of information in this
notice are in sections 3.04, 4.04, 4.05,
5.03, 5.04, 6.02(2), and 6.03(2) of this
notice.
The information requested in sections
3.04, 4.04, 5.03, and 6.02(2) of this notice
is required to obtain the benefit of choosing
one of the optional simplified methods of
determining AFSI with respect to a part-
nership investment provided in this notice.
This information will be used by the IRS
to confirm whether such a choice has been
made. The likely respondents are partner-
ships with corporate partners and corpora-
tions that are partners in partnerships.
The information requested in section 4.05
of this notice is required if a taxpayer chose
to obtain the benefit of making a taxable-in-
come election in section 4.03 of this notice
but no longer qualifies for the taxable-in-
come election. This information will be used
by the IRS to confirm that the taxpayer no
longer qualifies to make a taxable-income
election. The likely respondents are corpo-
rations that are partners in partnerships.
Section 5.04 of this notice simplifies the
partnership reporting requirements con-
tained in the CAMT proposed regulations.
Section 6.03(2) of this notice requires a
partnership to file a statement with its Fed-
eral income return or information return if it
chooses the full subchapter K method and
to maintain in its books and records compu-
tations substantiating compliance with the
full subchapter K method. The information
requested in section 6.03(2) of this notice is
required to obtain the benefit of using the
full subchapter K method. This information
5
See 89 F.R. at 75127.

Bulletin No. 2025–34 325 August 18, 2025
will be used by the IRS to confirm compli-
ance with the full subchapter K method.
The likely respondents are partnerships.
The reporting and third-party disclo-
sure requirements in this notice will be
included within OMB control number
1545-0123 in accordance with the PRA
procedures under 5 CFR § 1320.10. The
recordkeeping requirements are consid-
ered general tax records under § 1.6001-
1(e). For PRA purposes, general tax
records are already approved by OMB
under 1545-0123 for business filers.
Books or records relating to a collec-
tion of information must be retained as
long as their contents may become mate-
rial in the administration of any internal
revenue law. Generally, tax returns and
tax return information are confidential, as
required by § 6103.
SECTION 11. DRAFTING AND
CONTACT INFORMATION
The principal authors of this notice
are John Hanebuth, Jeremy Milton, Tim-
othy Steitz, and Benjamin Weaver of the
Office of the Associate Chief Counsel
(Passthroughs, Trusts, and Estates). Other
personnel from the Treasury Department
and the IRS participated in its develop-
ment. For further information regard-
ing this notice, please contact Messrs.
Hanebuth, Milton, Steitz, or Weaver at
(202) 317-6850.
Superfund Tax on
Chemical Substances;
Notice of Determinations
to Add Substances
to List of Taxable
Substances; Corrected
Name and Tax Rate for
Sodium Nitrilotriacetate
Monohydrate
Notice 2025-41
SUMMARY: This notice of determina-
tions modifies the list of taxable substances
to include the following 21 substances:
polyphenylene sulfide, cellulose acetate
(degree of substitution = 1.5 - 2.0), 4,4’-iso-
propylidenediphenol-epichlorohydrin
copolymer, nylon 6, caprolactam, methyl
ethyl ketoxime, iso-butanol, diethylene
glycol monomethyl ether, ethylene glycol
phenyl ether, methoxytriglycol, propylene
glycol methyl ether acetate, propylene gly-
col methyl ether, propylene glycol n-pro-
pyl ether, propylene glycol phenyl ether,
di-isobutyl carbinol, di-isobutyl ketone,
methyl isobutyl carbinol, cyanuric acid,
potassium bicarbonate, potassium carbon-
ate, and sodium chlorite. This notice also
modifies the list included in Notice 2021-
66 by correcting a typographical error
in the spelling of the name of the taxable
substance sodium nitrilotriacetate monohy-
drate and prescribing a tax rate for sodium
nitrilotriacetate monohydrate.
EFFECTIVE DATES: The effective date
for purposes of the tax under section 4671
of the Internal Revenue Code (Code) for
the taxable substances added to the list is
January 1, 2026. For the effective date for
purposes of refund claims under section
4662(e) of the Code for the taxable sub-
stances added to the list, see the determi-
nation for each substance. The tax rate for
sodium nitrilotriacetate monohydrate is
effective July 1, 2022.
FOR FURTHER INFORMATION
CONTACT: Andrew Clark or Jacob
Peeples at (202) 317-6855 (not a toll-free
number).
SUPPLEMENTARY INFORMATION:
Background
Section 4671(a) of the Code imposes
an excise tax on the sale or use of a taxable
substance by the importer thereof. Section
4672(a)(1) of the Code defines the term
taxable substance as any substance which,
at the time of sale or use by the importer,
is listed as a taxable substance by the Sec-
retary of the Treasury or the Secretary’s
delegate (Secretary) on the list of taxable
substances under section 4672(a) (List).
Under section 4672(a)(2), an importer
or exporter of any substance may request
that the Secretary determine whether such
substance should be added to the List as
a taxable substance or should be removed
from the List. Under section 4672(a)(2)
(B) and (4) and (b)(2), the Secretary is
required to add a substance to the List
if the Secretary determines that any tax-
able chemicals that are listed in section
4661(b) of the Code constitute more than
20 percent of the weight, or more than
20 percent of the value, of the materials
used to produce such substance, which
determination is required under section
4672(a)(2)(B) and (a)(4) to be made based
on the predominant method of production
(weight or value test). Section 4672(a)(4)
authorizes the Secretary to remove a sub-
stance from the List only if such substance
meets neither the weight nor the value test
of section 4672(a)(2)(B).
Section 4672(a)(3) includes an ini-
tial list of taxable substances. Section 4
of Notice 2021-66 (2021-52 I.R.B. 901)
provides the list of 101 substances that
the Secretary added to the List before
November 15, 2021. Rev. Proc. 2022-26
(2022-29 I.R.B. 90), as modified by Rev.
Proc. 2023-20 (2023-15 I.R.B. 636), pro-
vides the exclusive procedures by which
an importer, exporter, or interested person
may request a determination that a par-
ticular substance be added to or removed
from the List.
Section 4671(b)(3) authorizes the Sec-
retary to prescribe a tax rate for taxable
substances in lieu of the tax rate specified
in section 4671(b)(2). The tax rate pre-
scribed by the Secretary for a substance
added to the List is calculated by multiply-
ing the conversion factor for each taxable
chemical used in the production of the
substance by the corresponding tax rate
for that taxable chemical under section
4661(b), and adding those results together.
Conversion factors are determined based
on the predominant method of produc-
tion of the substance. See sections 8 and
10.04(8) of Rev. Proc. 2022-26. Import-
ers are not required to use the prescribed
tax rate for a taxable substance and may
calculate their own rate under section
4671(b)(1).
Pursuant to section 4672(a)(4), this
notice of determination modifies the List
to include the 21 additional taxable sub-
stances listed in the Summary of Determi-
nations section of this notice, as explained
in the Requests to Add Substances to the
List and General Explanation of Deter-
minations sections of this notice. The
determination for each specific substance

August 18, 2025 326 Bulletin No. 2025–34
added to the List is explained in parts I
through XXI of the Modifications to the
List of Taxable Substances section of this
notice.
In June 2022, the Secretary prescribed
rates for some of the substances listed
in section 4672(a)(3) and Notice 2021-
66.
1
The Correction to the List of Taxable
Substances section of this notice modifies
Notice 2021-66 by correcting a typographi-
cal error in the spelling of sodium nitrilotri-
acetate monohydrate and prescribing a tax
rate for the substance. The updated List and
prescribed tax rates for taxable substances
will be included in the instructions to Form
6627, Environmental Taxes.
Summary of Determinations
On August 1, 2025, the Secretary deter-
mined to add the following substances to
the List:
I. Polyphenylene sulfide
II. Cellulose acetate (degree of sub-
stitution = 1.5 - 2.0)
III. 4,4’-isopropylidenediphenol-epi-
chlorohydrin copolymer
IV. Nylon 6
V. Caprolactam
VI. Methyl ethyl ketoxime
VII. Iso-butanol
VIII. Diethylene glycol monomethyl
ether
IX. Ethylene glycol phenyl ether
X. Methoxytriglycol
XI. Propylene glycol methyl ether ace-
tate
XII. Propylene glycol methyl ether
XIII. Propylene glycol n-propyl ether
XIV. Propylene glycol phenyl ether
XV. Di-isobutyl carbinol
XVI. Di-isobutyl ketone
XVII. Methyl isobutyl carbinol
XVIII. Cyanuric acid
XIX. Potassium bicarbonate
XX. Potassium carbonate
XXI. Sodium chlorite
Requests to Add Substances to the List
For each of the substances listed in the
Summary of Determinations section of
this notice, an importer, an exporter, or
an interested person submitted a petition
to the IRS in accordance with Rev. Proc.
2022-26 requesting a determination under
section 4672(a)(2) to add the substance
to the List. For each substance, the peti-
tion represented that the taxable chem-
icals constitute more than 20 percent of
the weight of materials used to produce
the substance, based on the predominant
method of production.
General Explanation of Determinations
After reviewing the petitions for each
of the substances listed in the Summary of
Determinations section of this notice, the
Secretary determined that taxable chem-
icals constitute more than 20 percent by
weight of the materials used to produce
the substance, based on the predominant
method of production. Therefore, each
of the substances is added to the List as
required under section 4672(a)(2) and (4).
The Secretary made the determinations to
add these substances to the List in accor-
dance with the requirements of section
4672(a)(2) and (4), and pursuant to the
procedures set forth in Rev. Proc. 2022-
26, as modified by Rev. Proc. 2023-20.
The relevant information for each taxable
substance is provided in the specific deter-
minations included in parts I through XXI of
the Modification to the List of Taxable Sub-
stances section of this notice. The tax rate
for each taxable substance, as prescribed by
the Secretary, is provided in paragraph (a)(6)
of each specific determination.
Classification numbers proposed by
each petitioner are included in paragraph
(b) of each part, after each specific deter-
mination. The classification numbers
provided with respect to a taxable sub-
stance are not part of the determination
of whether it is added to the List and do
not impact whether such substance is a
taxable substance. Taxpayers may not rely
on classification numbers for any purpose
under sections 4661, 4662, 4671, and
4672, including (but not limited to) iden-
tification of a substance as a taxable sub-
stance on the List. Classification numbers
may change over time. The Department of
the Treasury (Treasury Department) and
the IRS do not anticipate updating this
document to reflect any such changes.
For purposes of the section 4671 tax, all
the modifications in parts I through XXI of
the Modification to the List of Taxable Sub-
stances section of this notice are effective
on and after January 1, 2026. For purposes
of refund claims under section 4662(e), see
the effective date for each specific deter-
mination in paragraph (a)(5)(ii) of each of
parts I through XXI of the Modification to
the List of Taxable Substances section of
this notice. The tax rate for sodium nitri-
lotriacetate monohydrate in the Correction
to the List of Taxable Substances section of
this notice is effective July 1, 2022.
Modifications to the List of Taxable
Substances
I. Determination to Add Polyphenylene
Sulfide to the List
Celanese Ltd., an exporter of poly-
phenylene sulfide, submitted a petition
in accordance with Rev. Proc. 2022-26
requesting to add polyphenylene sulfide
to the List. According to the petition, the
taxable chemicals sodium hydroxide, ben-
zene, and chlorine constitute 90.00 per-
cent by weight of the materials used to
produce polyphenylene sulfide, based on
the predominant method of production.
(a) Determination. Polyphenylene
sulfide is added to the list of taxable sub-
stances under section 4672(a). Other per-
tinent information is as follows:
(1) Predominant method of production:
The process involves three separate reactions:
(i) 1,4 dichlorobenzene is made from
the reaction of benzene with 2 equivalents
of chlorine;
(ii) Sodium hydrogen sulfide is made
from the reaction of hydrogen sulfide with
sodium hydroxide; and
(iii) 1,4-dichlorobenzene (p-dichloro-
benzene, p-DCB), sodium hydrosulfide
(NaSH), and sodium hydroxide (NaOH)
are reacted at high temperature and high
pressure to form polyphenylene sulfide
and byproduct sodium chloride.
(2) Stoichiometric material consump-
tion equation:
n [2 NaOH + C
6
H
6
+ 2 Cl
2
+ H
2
S] →
[C
6
H
4
S]
n
+ 2n H
2
O + 2n NaCl + 2n HCl
1
Available at https://www.irs.gov/newsroom/irs-issues-superfund-chemical-excise-tax-rates.

Bulletin No. 2025–34 327 August 18, 2025
(3) Reasons for the determination:
The polyphenylene sulfide petition was
filed on December 20, 2022. The notice
of filing summarizing the petition and
requesting comments was published
in the Federal Register (87 FR 80579)
on December 30, 2022. A supplemental
notice of filing announcing a corrected
petition and correction to the stoichio-
metric material consumption equation in
the original notice of filing and request-
ing comments was published in the Fed-
eral Register (89 FR 11941) on February
15, 2024. The Treasury Department and
the IRS received no written comments
in response to the original notice of fil-
ing or the supplemental notice of filing.
A public hearing was neither requested
nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation in
the corrected petition, as provided in the
supplemental notice of filing, and other
information in the petition shows that the
taxable chemicals sodium hydroxide, ben-
zene, and chlorine constitute more than 20
percent by weight of the materials used
in the production of polyphenylene sul-
fide, based on the predominant method of
production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of poly-
phenylene sulfide to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Sec-
retary: $14.50 per ton. The conversion
factors for the taxable chemicals used in
the production of polyphenylene sulfide
are 0.74 for sodium hydroxide, 0.72 for
benzene, and 1.31 for chlorine. The tax
rate is calculated by adding the products
of the conversion factor for each taxable
chemical and the tax rate for that taxable
chemical: ((0.74 x $0.56) + (0.72 x $9.74)
+ (1.31 x $5.40) = $14.50).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 3911.90.2500
(ii) Schedule B number: 3911.90.6100
(iii) CAS numbers: 25212-74-2, 26125-
40-6
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
II. Determination to Add Cellulose
Acetate (Degree of Substitution = 1.5 –
2.0) to the List
Celanese Ltd., an exporter of cellulose
acetate (degree of substitution = 1.5 – 2.0),
submitted a petition in accordance with
Rev. Proc. 2022-26 requesting to add cel-
lulose acetate (degree of substitution = 1.5
– 2.0) to the List. According to the petition,
the taxable chemical methane constitutes
greater than 20 percent
2
by weight, of the
materials used to produce cellulose acetate
(degree of substitution = 1.5 – 2.0), based
on the predominant method of production.
(a) Determination. Cellulose ace-
tate (degree of substitution = 1.5 – 2.0)
is added to the list of taxable substances
under section 4672(a). Other pertinent
information is as follows:
(1) Predominant method of production:
Cellulose acetate is derived from cellu-
lose by deconstructing wood pulp into a
purified cellulose. The cellulose is reacted
with acetic acid and acetic anhydride in the
presence of sulfuric acid. It is subjected to
a controlled, partial hydrolysis to remove
the sulfate and a sufficient number of ace-
tate groups to give the product the desired
degree of substitution. The polymer unit
is the fundamental repeating structure of
cellulose and has three hydroxyl groups
which can react to form acetate esters.
The most common form of cellulose ace-
tate fiber has an acetate group on approx-
imately two of every three hydroxyls,
referred to as cellulose diacetate. In this
petitioner’s cellulose acetate, the actual
substitution is 1.674 acetate/cellulose, a
degree of substitution commonly used in
U.S. cellulose acetate production.
(2) Stoichiometric material consump-
tion equation:
3.5 CH
4
+ 1.75 O
2
+ C
6
H
10
O
5
→
C
9
.
5
H
13.5
O
6.75
+ 3.50 H
2
+ 1.75 H
2
O
(3) Reasons for the determination: The
cellulose acetate (degree of substitution =
1.5 – 2.0) petition was filed on December
20, 2022. The notice of filing summariz-
ing the petition and requesting comments
was published in the Federal Register (88
FR 16307) on March 16, 2023. The Trea-
sury Department and the IRS received
no written comments in response to the
notice of filing. A public hearing was nei-
ther requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation
and other information in the petition
shows that the taxable chemical meth-
ane constitutes more than 20 percent
by weight of the materials used in the
production of cellulose acetate (degree
of substitution = 1.5 – 2.0), based on
the predominant method of production.
Therefore, the test in section 4672(a)(2)
(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of cellu-
lose acetate (degree of substitution = 1.5
– 2.0) to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Secre-
tary: $1.65 per ton. The conversion factor
for the methane used in the production of
cellulose acetate (degree of substitution =
1.5 – 2.0) is 0.24. The tax rate is calcu-
lated by multiplying the conversion factor
by the tax rate for methane: (0.24 x $6.88
= $1.65).
(b) Classification numbers.
2
The petition covers cellulose acetate (degree of substitution = 1.5 – 2.0), commonly referred to as cellulose diacetate. Cellulose acetate in this range generally has similar properties. The
petition uses the lowest end of the range cellulose acetate (degree of substitution = 1.5) (21 percent taxable chemicals) to demonstrate that >20% of the substance is made from taxable chem-
icals, and the midpoint cellulose acetate (degree of substitution = 1.75) (24 percent taxable chemicals) to calculate the tax rate for the entire range.

August 18, 2025 328 Bulletin No. 2025–34
(1) The Secretary has no basis to object
to the following proposed classification
number: CAS number: 9035-69-2
(2) The Secretary is unable to con-
firm the following proposed classification
numbers:
(i) HTSUS numbers: 5502.10.0000,
5403.33.0020
(ii) Schedule B numbers: 5502.10.0000,
5403.33.0000
III. Determination to Add
4,4’-Isopropylidenediphenol-
Epichlorohydrin Copolymer to the List
Westlake Epoxy Inc., an exporter of
4,4’-isopropylidenediphenol-epichlo-
rohydrin copolymer, also known as
“bisphenol A epoxy resin,” submitted a
petition in accordance with Rev. Proc.
2022-26 requesting to add 4,4’-iso-
propylidenediphenol-epichlorohydrin
copolymer to the List. According to the
petition, the taxable chemicals benzene,
propylene, chlorine, and sodium hydrox-
ide constitute 92.98 percent by weight of
the materials used to produce 4,4’-iso-
propylidenediphenol-epichlorohydrin
copolymer, based on the predominant
method of production.
(a) Determination. 4,4’-isopro-
pylidenediphenol-epichlorohydrin copo-
lymer, also known as “bisphenol A epoxy
resin,” is added to the list of taxable sub-
stances under section 4672(a). Other per-
tinent information is as follows:
(1) Predominant method of produc-
tion: 4,4’-isopropylidenediphenol-epi-
chlorohydrin copolymer is produced from
epichlorohydrin and bisphenol-A via a
two-step glycidation reaction sequence.
Epichlorohydrin is typically produced
via an addition reaction of chlorine to
propylene that yields allyl chloride and
subsequently dichlorohydrin isomers,
followed by a dehydrochlorination step
in the presence of sodium hydroxide to
yield epichlorohydrin. Bisphenol A is
typically produced from the reaction of
benzene and propylene that yields phenol
and acetone. Under acidic conditions and
with an appropriate catalyst, two units of
phenol can react with one unit of acetone
to yield Bisphenol A. With available epi-
chlorohydrin and Bisphenol A, 4,4’-iso-
propylidenediphenol-epichlorohydrin
copolymer can be obtained through a two-
step glycidation reaction sequence where
epichlorohydrin is added to Bisphenol A
(deprotonated with sodium hydroxide)
and then water, sodium hydroxide, and
sodium chloride are removed in a dehy-
drochlorination step.
(2) Stoichiometric material consump-
tion equation:
2 C
6
H
6
(benzene) + 4 C
3
H
6
(propylene)
+ 4 Cl
2
(chlorine) + 6 NaOH (sodium
hydroxide) + 2 O
2
(oxygen) →
(CH
3
)
2
C(C
6
H
4
OC
3
H
5
O)
2
(4,4’-isopro-
pylidenediphenol-epichlorohydrin
copolymer) + CH
3
COCH
3
(acetone) +
2 HCl (hydrogen chloride) + 6 NaCl
(sodium chloride) + 5 H
2
O (water)
(3) Reasons for the determination:
The 4,4’-isopropylidenediphenol-epi-
chlorohydrin copolymer petition was
filed on December 20, 2022. The notice
of filing summarizing the petition and
requesting comments was published in
the Federal Register (88 FR 3478) on
January 19, 2023. The Treasury Depart-
ment and the IRS received no written
comments in response to the notice
of filing. A public hearing was neither
requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation
and other information in the petition
shows that the taxable chemicals ben-
zene, propylene, chlorine, and sodium
hydroxide constitute more than 20 per-
cent by weight of the materials used in
the production of 4,4’-isopropylidenedi-
phenol-epichlorohydrin copolymer,
based on the predominant method of
production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of
4,4’-isopropylidenediphenol-epichlorohy-
drin copolymer to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Secretary:
$14.13 per ton. The conversion factors for
the taxable chemicals used in the produc-
tion of 4,4’-isopropylidenediphenol-epi-
chlorohydrin copolymer are 0.46 for ben-
zene, 0.49 for propylene, 0.83 for chlorine,
and 0.71 for sodium hydroxide. The tax
rate is calculated by adding the products
of the conversion factor for each taxable
chemical and the tax rate for that taxable
chemical: ((0.46 x $9.74) + (0.49 x $9.74)
+ (0.83 x $5.40) + (0.71 x $0.56) = $14.13).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 3907.30.0000
(ii) Schedule B number: 3907.30.0000
(iii) CAS number: 25068-38-6
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
IV. Determination to Add Nylon 6 to
the List
AdvanSix Inc., an exporter of nylon
6, submitted a petition in accordance
with Rev. Proc. 2022-26 requesting to
add nylon 6 to the List. According to the
petition, nylon 6 is made from the taxable
chemicals benzene, propylene, ammonia,
methane, and sulfuric acid; however, sul-
furic acid is cancelled from the stoichio-
metric material consumption equation due
to no net consumption/production. The
petition further represented that the ben-
zene, propylene, ammonia, and methane
constitute 46.64 percent by weight of the
materials used to produce nylon 6, based
on the predominant method of production.
(a) Determination. Nylon 6 is added to
the list of taxable substances under section
4672(a). Other pertinent information is as
follows:
(1) Predominant method of production:
The predominant method of production
of nylon 6 is the “hydrolytically initiated
ring-opening polymerization of caprolac-
tam” which is also referred to in industry
literature as the “hydrolytic polymerization
of nylon 6.” This process is termed “hydro-
lytic” because water plays a key role in the
chemical mechanism. Nylon 6 is produced
almost exclusively through this method
because it is easier to control and better
adapted for large-scale operations.

Bulletin No. 2025–34 329 August 18, 2025
The hydrolytic polymerization of nylon
6 generally entails heating a mixture of
caprolactam and water to ~270°C in an
inert atmosphere of nitrogen and holding
until equilibrium conditions are achieved.
The three principal reactions in this pro-
cess are summarized below:
(i) In the initiation step of the process,
the caprolactam ring is hydrolyzed via ring
opening with the addition of one water
molecule to become amino-caproic acid.
(ii) In the next step of the mechanism,
the amino-caproic acid acts as the initiat-
ing species to begin the addition polym-
erization by ring-opening of caprolactam.
(iii) The last major mechanism step of
the hydrolytic polymerization of nylon 6
is the condensation of primary amine and
carboxylic acid chain-ends to form an
amide linkage in the now higher molecu-
lar weight polyamide with the simultane-
ous loss of a water molecule.
(2) Stoichiometric material consump-
tion equation:
nC
6
H
6
(benzene) + nC
3
H
6
(propylene)
+ 2.5nO
2
(oxygen) + 0.5nCH
4
(meth-
ane) + 5nNH
3
(ammonia) + 2nH
2
O
(water) + 2nSO
2
(sulfur dioxide) →
(C
6
H
11
NO)
n
(nylon 6) + nC
3
H
6
O
(acetone) + 2n(NH
4
)
2
SO
4
(ammonium
sulfate) + 0.5nCO
2
(carbon dioxide)
(3) Reasons for the determination: The
nylon 6 petition was filed on November
8, 2023. The notice of filing summariz-
ing the petition and requesting comments
was published in the Federal Register
on February 22, 2024 (89 FR 13399). A
supplemental notice of filing announcing
a corrected petition, correction to the stoi-
chiometric material consumption equa-
tion in the original notice of filing, and
requesting comments was published in
the Federal Register (89 FR 66175) on
August 14, 2024. The Treasury Depart-
ment and the IRS received no written
comments in response to the notice of
filing and received one written comment
in response to the supplemental notice of
filing, discussed below. A public hearing
was neither requested nor held.
The public comment submitted in
response to the supplemental notice
of filing generally wrote in support of
adding nylon 6 to the list of taxable
substances. However, the commenter
requested that the Treasury Department
and the IRS add to the list of taxable
substances the categories ‘nylon resins’
or ‘polyamides’ rather than merely the
single taxable substance nylon 6. The
commenter asserts that nylon 6 is one of
the many grades of nylons or polyamides
which contain more than 20 percent of
taxable chemicals.
At this time, the Treasury Department
and the IRS decline to add the additional
categories of nylon resins and polyam-
ides to the List, as suggested by the com-
menter. The filed petition that is the sub-
ject of this determination requested only
to add the substance nylon 6 to the List, so
a comment that the Treasury Department
and the IRS should add additional sub-
stances to the List is outside the scope of
the determination for nylon 6. To request
to add nylon resins and polyamides to the
List, an importer, exporter, or interested
person must follow the determination
procedures provided under Rev. Proc.
2022-26, including submitting a petition
for each substance with the required infor-
mation. See sections 4 and 6 of Rev. Proc.
2022-26.
The Secretary followed the process
in section 4672(a)(2)(B) in making the
determination to add nylon 6 to the List.
A review of the stoichiometric material
consumption equation in the corrected
petition, as provided in the supplemental
notice of filing, and other information in
the petition shows that the taxable chem-
icals benzene, propylene, ammonia, and
methane constitute more than 20 percent
by weight of the materials used in the pro-
duction of nylon 6, based on the predomi-
nant method of production. Therefore, the
test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of nylon
6 to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Sec-
retary: $14.77 per ton. The conversion
factors for the taxable chemicals used
in the production of nylon 6 are 0.69 for
benzene, 0.37 for propylene, 0.75 for
ammonia, and 0.07 for methane. The tax
rate is calculated by adding the products
of the conversion factor for each taxable
chemical and the tax rate for that tax-
able chemical: ((0.69 x $9.74) + (0.37 x
$9.74) + (0.75 x $5.28) + (0.07 x $6.88)
= $14.77).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 3908.10.00
(ii) Schedule B number: 3908.10.0000
(iii) CAS number: 25038-54-4
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
V. Determination to Add Caprolactam
to the List
AdvanSix Inc., an exporter of capro-
lactam, submitted a petition in accordance
with Rev. Proc. 2022-26 requesting to add
caprolactam to the List. According to the
petition, caprolactam is made from the
taxable chemicals benzene, propylene,
ammonia, methane, and sulfuric acid;
however, sulfuric acid is cancelled from
the stoichiometric material consumption
equation due to no net consumption/pro-
duction. The petition also represented
that the benzene, propylene, ammonia,
and methane constitute 46.64 percent by
weight of the materials used to produce
caprolactam, based on the predominant
method of production.
(a) Determination. Caprolactam is
added to the list of taxable substances
under section 4672(a). Other pertinent
information is as follows:
(1) Predominant method of produc-
tion: Caprolactam is produced by first
oxidizing cumene to yield phenol, which
is then partially reduced with hydrogen to
yield cyclohexanone. Cyclohexanone is
then reacted with Raschig hydroxylamine
to generate cyclohexanone oxime. The
cyclohexanone oxime undergoes Beck-
mann rearrangement in the presence of
fuming sulfuric acid (oleum) to give an
intermediate material known as rearrange-
ment mass, which is subsequently hydro-
lyzed and then neutralized with ammonia
to yield ε-caprolactam.

August 18, 2025 330 Bulletin No. 2025–34
(2) Stoichiometric material consump-
tion equation:
C
6
H
6
(benzene) + C
3
H
6
(propylene) +
2.5 O
2
(oxygen) + 0.5 CH
4
(methane) +
5 NH
3
(ammonia) + 2 H
2
O (water) +
2 SO
2
(sulfur dioxide) → C
6
H
11
ON
(ε-caprolactam) + C
3
H
6
O (acetone) +
2(NH
4
)
2
SO
4
(ammonium sulfate) +
0.5 CO
2
(carbon dioxide)
(3) Reasons for the determination:
The caprolactam petition was filed on
November 8, 2023. The notice of filing
summarizing the petition and requesting
comments was published in the Federal
Register (89 FR 13400) on February 22,
2024. The Treasury Department and the
IRS received no written comments in
response to the notice of filing. A public
hearing was neither requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation and
other information in the petition shows
that the taxable chemicals benzene, pro-
pylene, ammonia, and methane constitute
more than 20 percent by weight of the
materials used in the production of capro-
lactam, based on the predominant method
of production. Therefore, the test in sec-
tion 4672(a)(2)(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of
caprolactam to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): January 1, 2023
(6) Tax rate prescribed by the Sec-
retary: $14.77 per ton. The conversion
factors for the taxable chemicals used in
the production of caprolactam are 0.69
for benzene, 0.37 for propylene, 0.75 for
ammonia, and 0.07 for methane. The tax
rate is calculated by adding the products
of the conversion factor for each taxable
chemical and the tax rate for that tax-
able chemical: ((0.69 x $9.74) + (0.37 x
$9.74) + (0.75 x $5.28) + (0.07 x $6.88)
= $14.77).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2933.71.00
(ii) Schedule B number: 2933.71.0000
(iii) CAS number: 105-60-2
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
VI. Determination to Add Methyl
Ethyl Ketoxime to the List
AdvanSix Inc., an exporter of methyl
ethyl ketoxime (commonly referred to as
MEKO), submitted a petition in accor-
dance with Rev. Proc. 2022-26 requesting
to add methyl ethyl ketoxime to the List.
According to the petition, methyl ethyl
ketoxime is made from the taxable chem-
icals ammonia, sulfuric acid, and butylene;
however, sulfuric acid is cancelled from the
stoichiometric material consumption equa-
tion due to no net consumption/produc-
tion. The petition further represented that
ammonia and butylene constitute 39.97
percent by weight of the materials used to
produce methyl ethyl ketoxime, based on
the predominant method of production.
(a) Determination. Methyl ethyl ketox-
ime is added to the list of taxable sub-
stances under section 4672(a). Other per-
tinent information is as follows:
(1) Predominant method of production:
The conventional method was developed
in the late 1960s via a route that involves
condensation of methyl ethyl ketone with
a hydroxylamine salt in the presence of
a base. More specifically, methyl ethyl
ketone is oximated with Raschig hydrox-
ylamine to yield methyl ethyl ketoxime.
(2) Stoichiometric material consump-
tion equation:
C
4
H
8
(butylene) + 5 NH
3
(ammonia) +
2 H
2
O (water) + 1.5 O
2
(oxygen) +
2 SO
2
(sulfur dioxide) → C
4
H
9
ON
(methyl ethyl ketoxime) + 2
(NH
4
)
2
SO
4
(ammonium sulfate) + H
2

(hydrogen)
(3) Reasons for the determination: The
methyl ethyl ketoxime petition was filed
on July 10, 2023. The notice of filing
summarizing the petition and requesting
comments was published in the Federal
Register (88 FR 45454) on July 17, 2023.
The Treasury Department and the IRS
received no written comments in response
to the notice of filing. A public hearing
was neither requested nor held.
The Secretary followed the process in
section 4672(a)(2)(B) in making this deter-
mination. A review of the stoichiometric
material consumption equation and other
information in the petition shows that the
taxable chemicals ammonia and butylene
constitute more than 20 percent by weight
of the materials used in the production of
methyl ethyl ketoxime, based on the pre-
dominant method of production. Therefore,
the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of
methyl ethyl ketoxime to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): January 1, 2023
(6) Tax rate prescribed by the Secre-
tary: $11.41 per ton. The conversion fac-
tors for the taxable chemicals used in the
production of methyl ethyl ketoxime are
0.98 for ammonia and 0.64 for butylene.
The tax rate is calculated by adding the
products of the conversion factor for each
taxable chemical and the tax rate for that
taxable chemical: ((0.98 x $5.28) + (0.64
x $9.74) = $11.41).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2928.00.10
(ii) Schedule B number: 2928.00.1000
(iii) CAS number: 96-29-7
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
VII. Determination to Add Iso-butanol
to the List
OQ Chemicals Corporation, an
exporter of iso-butanol, submitted a peti-
tion in accordance with Rev. Proc. 2022-
26 requesting to add iso-butanol to the
List. According to the petition, the taxable

Bulletin No. 2025–34 331 August 18, 2025
chemicals methane and propylene consti-
tute 78.41 percent by weight of the mate-
rials used to produce iso-butanol, based on
the predominant method of production.
(a) Determination. Iso-butanol is added
to the list of taxable substances under sec-
tion 4672(a). Other pertinent information
is as follows:
(1) Predominant method of production:
Iso-butanol is co-produced by hydro-
formylation of propylene to produce both
iso-butyraldehyde and n-butyraldehyde
followed by hydrogenation of the alde-
hyde intermediates to the corresponding
iso-butanol and n-butanol. The predomi-
nant method of production is as follows:
(i) Partial oxidation of methane with
oxygen to produce synthesis gas, a mix-
ture of carbon monoxide and hydrogen.
This petitioner uses a Partial Oxidation
(POX) process that is non catalytic but
operates at >1300 deg C and >40 atm
pressure. Thus, synthesis gas is produced
from methane and oxygen:
CH
4
+ ½ O
2
→ CO + 2H
2
(ii) Oxo process: Hydroformylation
of propylene with carbon monoxide
and hydrogen over a catalyst to produce
iso-butyraldehyde. The reaction also
produces normal butyraldehyde simul-
taneously; the stoichiometry is the same
for either the iso or the normal aldehyde.
Thus, iso-butyraldehyde is produced from
propylene and syngas.
CO + H
2
+ CH
2
=CH-CH
3
→
(CH
3
)
2
-CH-CHO
(iii) Iso-butyraldehyde is hydroge-
nated with hydrogen over a catalyst. Thus,
iso-butanol is produced from iso-butyral-
dehyde and hydrogen.
(CH
3
)
2
-CH-CHO + H
2
→
(CH
3
)
2
CHCH
2
OH
(2) Stoichiometric material consump-
tion equation:
CH
4
(methane) + ½ O
2
+ CH
2
=
CH-CH
3
(propylene) → (CH
3
)
2
CH-
CH
2
OH (iso-butanol)
(3) Reasons for the determination: The
iso-butanol petition was filed on January
25, 2024. The notice of filing summariz-
ing the petition and requesting comments
was published in the Federal Register
(89 FR 14558) on February 27, 2024.
The Treasury Department and the IRS
received no written comments in response
to the notice of filing. A public hearing
was neither requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation and
other information in the petition shows
that the taxable chemicals methane and
propylene constitute more than 20 per-
cent by weight of the materials used in
the production of iso-butanol, based on
the predominant method of production.
Therefore, the test in section 4672(a)(2)
(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of
iso-butanol to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): April 1, 2023
(6) Tax rate prescribed by the Secre-
tary: $7.07 per ton. The conversion fac-
tors for the taxable chemicals used in the
production of iso-butanol are 0.22 for
methane and 0.57 for propylene. The tax
rate is calculated by adding the products
of the conversion factor for each taxable
chemical and the tax rate for that taxable
chemical: ((0.22 x $6.88) + (0.57 x $9.74)
= $7.07).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2905.14.50.10
(ii) Schedule B number: 2905.14.5010
(iii) CAS number: 78-83-1
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
VIII. Determination to Add Diethylene
Glycol Monomethyl Ether to the List
The Dow Chemical Company,
an exporter of diethylene glycol
monomethyl ether, submitted a petition
in accordance with Rev. Proc. 2022-
26 requesting to add diethylene glycol
monomethyl ether to the List. According
to the petition, the taxable chemicals eth-
ylene and methane constitute 59.00 per-
cent by weight of the materials used to
produce diethylene glycol monomethyl
ether, based on the predominant method
of production.
(a) Determination. Diethylene gly-
col monomethyl ether is added to the
list of taxable substances under section
4672(a). Other pertinent information is
as follows:
(1) Predominant method of produc-
tion: Glycol ethers are predominantly
produced by reacting an epoxide (typi-
cally ethylene oxide or propylene oxide)
with an alcohol; this reaction process is
referred to as alkoxylation. Diethylene
glycol monomethyl ether (C
5
H
12
O
3
) is
produced by the alkoxylation process
using methanol (CH
3
OH) and 2 equiva-
lents of ethylene oxide (C
2
H
4
O). Metha-
nol is made from syngas (carbon monox-
ide and dihydrogen). Carbon monoxide
(CO) and dihydrogen (H
2
) are made by
steam-methane reforming (CH
4
and
H
2
O). Ethylene oxide (EO) is made from
oxidizing ethylene (C
2
H
4
). Additional
information on the production process is
as follows:
(i) The diethylene glycol monomethyl
ether reaction (methanol + EO) is base
catalyzed, using a small amount of metal
hydroxide to produce methoxide. Since
the amount of metal hydroxide used to
produce diethylene glycol monomethyl
ether
3
is very small, the metal hydroxide
has been excluded from the stoichiometric
material consumption equation; including
the metal hydroxide would lead to a dis-
torted conversion factor.
(ii) Once methoxide is made, it is
regenerated following conversion to the
product in the presence of EO as follows:
(A) Methoxide + 2 EO → diethylene
glycol monomethyl ether-alkoxide
3
The Notice of Filing erroneously stated, “Since the amount of metal hydroxide used to produce propylene glycol methyl ether...” This error is corrected here.

August 18, 2025 332 Bulletin No. 2025–34
(B) Diethylene glycol monomethyl
ether-alkoxide + methanol → diethylene
glycol monomethyl ether + methoxide
(goes back to participate in the reaction
above).
(iii) Regenerated methoxide in the
presence of EO will perpetually react
until all EO is consumed or the reaction is
halted through the use of controls.
(2) Stoichiometric material consump-
tion equation:
2 C
2
H
4
(ethylene) + O
2
(oxygen) +
CH
4
(methane) + H
2
O (water) →
H
2
(hydrogen) + C
5
H
12
O
3
(diethylene
glycol monomethyl ether)
(3) Reasons for the determination:
The diethylene glycol monomethyl ether
petition was filed on June 13, 2024. The
notice of filing summarizing the petition
and requesting comments was published
in the Federal Register (89 FR 71788) on
September 3, 2024. The Treasury Depart-
ment and the IRS received no written
comments in response to the notice
of filing. A public hearing was neither
requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation
and other information in the petition
shows that the taxable chemicals eth-
ylene and methane constitute more than
20 percent by weight of the materials
used in the production of diethylene gly-
col monomethyl ether, based on the pre-
dominant method of production. There-
fore, the test in section 4672(a)(2)(B) is
satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of dieth-
ylene glycol monomethyl ether to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Secre-
tary: $5.47 per ton. The conversion factors
for the taxable chemicals used in the pro-
duction of diethylene glycol monomethyl
ether are 0.47 for ethylene and 0.13 for
methane. The tax rate is calculated by add-
ing the products of the conversion factor
for each taxable chemical and the tax rate
for that taxable chemical: ((0.47 x $9.74)
+ (0.13 x $6.88) = $5.47).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2909.44.01.10
(ii) Schedule B number: 2909.49.0000
(iii) CAS number: 111-77-3
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
IX. Determination to Add Ethylene
Glycol Phenyl Ether to the List
The Dow Chemical Company, an
exporter of ethylene glycol phenyl ether,
submitted a petition in accordance with
Rev. Proc. 2022-26 requesting to add
ethylene glycol phenyl ether to the List.
According to the petition, the taxable
chemicals ethylene, benzene, and propyl-
ene constitute 76.00 percent by weight of
the materials used to produce ethylene
glycol phenyl ether, based on the predom-
inant method of production.
(a) Determination. Ethylene glycol
phenyl ether is added to the list of taxable
substances under section 4672(a). Other
pertinent information is as follows:
(1) Predominant method of produc-
tion: Glycol ethers are predominantly
produced by reacting an epoxide (typi-
cally ethylene oxide or propylene oxide)
with an alcohol; this reaction process
is referred to as alkoxylation. Ethylene
glycol phenyl ether (C
8
H
10
O
2
) is pro-
duced by the alkoxylation process using
phenol (CH
3
OH) and ethylene oxide
(C
2
H
4
O). Ethylene oxide is made by
oxidizing ethylene (C
2
H
4
). Phenol is
made via the Hock process (sometimes
called the cumene process). The Hock
process has two stages. In stage 1, ben-
zene (C
6
H
6
) is alkylated with propylene
(C
3
H
6
) to make cumene (isopropyl ben-
zene). In stage 2, cumene (C
6
H
5
(C
3
H
7
))
is partially oxidized to make phenol
(C
6
H
5
OH) and side product dimethyl
ketone ((CH
3
)
2
CHO)).
(2) Stoichiometric material consump-
tion equation:
C
2
H
4
(ethylene) + 1.5 O
2
(oxygen) +
C
6
H
6
(benzene) + C
3
H
6
(propylene) →
C
3
H
6
O (dimethyl ketone) + C
8
H
10
O
2

(ethylene glycol phenyl ether)
(3) Reasons for the determination:
The ethylene glycol phenyl ether peti-
tion was filed on June 13, 2024. The
notice of filing summarizing the petition
and requesting comments was published
in the Federal Register (89 FR 71785)
on September 3, 2024. The Treasury
Department and the IRS received no
written comments in response to the
notice of filing. A public hearing was
neither requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation and
other information in the petition shows
that the taxable chemicals ethylene, ben-
zene, and propylene constitute more than
20 percent by weight of the materials
used in the production of ethylene glycol
phenyl ether, based on the predominant
method of production. Therefore, the test
in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of eth-
ylene glycol phenyl ether to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Secre-
tary: $10.42 per ton. The conversion fac-
tors for the taxable chemicals used in the
production of ethylene glycol phenyl ether
are 0.20 for ethylene, 0.57 for benzene,
and 0.30 for propylene. The tax rate is cal-
culated by adding the products of the con-
version factor for each taxable chemical
and the tax rate for that taxable chemical:
((0.20 x $9.74) + (0.57 x $9.74) + (0.30 x
$9.74) = $10.42).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) Schedule B number: 2909.49.0000
(ii) CAS number: 122-99-6

Bulletin No. 2025–34 333 August 18, 2025
(2) The Secretary is unable to con-
firm the following proposed classification
number:
HTSUS number: 2909.49.60.00
X. Determination to Add
Methoxytriglycol to the List
The Dow Chemical Company, an
exporter of methoxytriglycol, submitted
a petition in accordance with Rev. Proc.
2022-26 requesting to add methoxytrigly-
col to the List. According to the petition,
the taxable chemicals ethylene and meth-
ane constitute 60.00 percent by weight of
the materials used to produce methoxytri-
glycol, based on the predominant method
of production.
(a) Determination. Methoxytriglycol
is added to the list of taxable substances
under section 4672(a). Other pertinent
information is as follows:
(1) Predominant method of production:
Glycol ethers are predominantly produced
by reacting an epoxide (typically ethylene
oxide or propylene oxide) with an alco-
hol; this reaction process is referred to as
alkoxylation. Methoxytriglycol (C
7
H
16
O
4
)
is produced by the alkoxylation process
using methanol (CH
3
OH) and 3 equiva-
lents of ethylene oxide (C
2
H
4
O). Metha-
nol is made from syngas (carbon monox-
ide and dihydrogen). Carbon monoxide
(CO) and dihydrogen (H
2
) are made by
steam-methane reforming (CH
4
and H
2
O).
Ethylene oxide (EO) is made from oxidiz-
ing ethylene (C
2
H
4
). Additional informa-
tion on the production process is as fol-
lows:
(i) The methoxytriglycol reaction
(methanol + EO) is base catalyzed, using
a small amount of metal hydroxide to pro-
duce methoxide. Since the amount of metal
hydroxide used to produce methoxytrigly-
col
4
is very small, the metal hydroxide has
been excluded from the stoichiometric
material consumption equation; including
the metal hydroxide would lead to a dis-
torted conversion factor.
(ii) Once methoxide is made, it is
regenerated following conversion to the
product in the presence of EO as follows:
(A) Methoxide + 3 EO → methoxytri-
glycol- alkoxide
(B) Methoxytriglycol-alkoxide +
methanol → methoxytriglycol + methox-
ide (goes back to participate in the reac-
tion above).
(iii) Regenerated methoxide in the
presence of EO will perpetually react
until all EO is consumed or the reaction is
halted through the use of controls.
(2) Stoichiometric material consump-
tion equation:
3 C
2
H
4
(ethylene) + 1.5 O
2
(oxygen) +
CH
4
(methane) + H
2
O (water) →
H
2
(hydrogen) + C
7
H
16
O
4

(methoxytriglycol)
(3) Reasons for the determination:
The methoxytriglycol petition was filed
on June 13, 2024. The notice of filing
summarizing the petition and requesting
comments was published in the Federal
Register (89 FR 71789) on September
3, 2024. The Treasury Department and
the IRS received no written comments in
response to the notice of filing. A public
hearing was neither requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation and
other information in the petition shows
that the taxable chemicals ethylene and
methane constitute more than 20 percent
by weight of the materials used in the
production of methoxytriglycol, based on
the predominant method of production.
Therefore, the test in section 4672(a)(2)
(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of
methoxytriglycol to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Secre-
tary: $5.66 per ton. The conversion fac-
tors for the taxable chemicals used in the
production of methoxytriglycol are 0.51
for ethylene and 0.10 for methane. The tax
rate is calculated by adding the products
of the conversion factor for each taxable
chemical and the tax rate for that taxable
chemical: ((0.51 x $9.74) + (0.10 x $6.88)
= $5.66).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2909.49.6000
(ii) Schedule B number: 2922.17.0000
(iii) CAS number: 112-35-6
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
XI. Determination to Add Propylene
Glycol Methyl Ether Acetate to the List
The Dow Chemical Company, an
importer and exporter of propylene glycol
methyl ether acetate, submitted a petition
in accordance with Rev. Proc. 2022-26
requesting to add propylene glycol methyl
ether acetate to the List. According to the
petition, the taxable chemicals propylene,
chlorine, sodium hydroxide, and methane
constitute 93.00 percent by weight of the
materials used to produce propylene gly-
col methyl ether acetate, based on the pre-
dominant method of production.
(a) Determination. Propylene glycol
methyl ether acetate is added to the list of
taxable substances under section 4672(a).
Other pertinent information is as follows:
(1) Predominant method of production:
Glycol ethers are predominantly produced
by reacting an epoxide (typically ethylene
oxide or propylene oxide) with an alco-
hol; this reaction process is referred to
as alkoxylation. Propylene glycol methyl
ether acetate is made by esterification of
propylene glycol methyl ether and acetic
acid. Propylene glycol methyl ether is
made via the alkoxylation process (also
known as ring opening of an epoxide)
using methanol and propylene oxide.
Methanol is made from syngas (carbon
monoxide and dihydrogen). Carbon mon-
oxide (CO) and dihydrogen (H
2
) are made
by steam-methane reforming (CH
4
and
H
2
O). Propylene oxide is made by hydro-
chlorination (chlorine (Cl
2
), propylene
4
The Notice of Filing erroneously stated, “Since the amount of metal hydroxide used to produce propylene glycol methyl ether...” This error is corrected here.

August 18, 2025 334 Bulletin No. 2025–34
(C
3
H
6
), and sodium hydroxide (NaOH)).
Acetic acid is made via the carbonylation
of methanol with carbon monoxide. Addi-
tional information on the production pro-
cess is as follows:
(i) The propylene glycol methyl ether
alkoxylation reaction (methanol + propyl-
ene oxide) is base catalyzed, using a small
amount of metal hydroxide to produce
methoxide. Once methoxide is made, it is
regenerated following conversion to the
product in the presence of propylene oxide.
Regenerated methoxide in the presence of
propylene oxide will perpetually react until
all propylene oxide is consumed or the
reaction is halted through the use of con-
trols. Since the amount of metal hydroxide
used to produce propylene glycol methyl
ether acetate
5
is very small, the metal
hydroxide has been excluded from the stoi-
chiometric material consumption equation;
including the metal hydroxide would lead
to a distorted conversion factor.
(ii) After the production of methanol
from syngas, methanol is reacted with
CO to produce acetic acid. This process
is commonly referred to as carbonylation.
The reaction is typically catalyzed by
either a rhodium or iridium-based catalyst
and involves iodomethane as a key inter-
mediate.
(iii) Acetic acid when combined with
propylene glycol methyl under specific
conditions (temperature, pressure, pH,
etc.) produces propylene glycol methyl
ether acetate. This reaction is commonly
known as esterification (or Fischer ester-
ification). Esterification typically involves
a basic or acid catalytic species and can
generate water or an aqueous hydroxide as
byproduct depending on the pH. Once the
final reaction contents are dehydrated and
separated, commercial grade propylene
glycol methyl ether acetate is obtained.
(2) Stoichiometric material consump-
tion equation:
C
3
H
6
(propylene) + Cl
2
(chlorine) +
2 NaOH (sodium hydroxide) +
3 CH
4
(methane) + H
2
O (water) →
2 NaCl (sodium chloride) + 5 H
2

(hydrogen) + C
6
H
12
O
3
(propylene
glycol methyl ether acetate)
(3) Reasons for the determination: The
propylene glycol methyl ether acetate peti-
tion was filed on June 13, 2024. The notice
of filing summarizing the petition and
requesting comments was published in the
Federal Register (89 FR 71789) on Sep-
tember 3, 2024. The Treasury Department
and the IRS received no written comments
in response to the notice of filing. A public
hearing was neither requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation and
other information in the petition shows
that the taxable chemicals propylene,
chlorine, sodium hydroxide, and methane
constitute more than 20 percent by weight
of the materials used in the production
of propylene glycol methyl ether ace-
tate, based on the predominant method of
production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of pro-
pylene glycol methyl ether acetate to the
List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Sec-
retary: $8.85 per ton. The conversion
factors for the taxable chemicals used
in the production of propylene glycol
methyl ether acetate are 0.32 for propyl-
ene, 0.54 for chlorine, 0.61 for sodium
hydroxide, and 0.36 for methane. The
tax rate is calculated by adding the prod-
ucts of the conversion factor for each
taxable chemical and the tax rate for
that taxable chemical: ((0.32 x $9.74) +
(0.54 x $5.40) + (0.61 x $0.56) + (0.36 x
$6.88) = $8.85).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2915.39.90.00
(ii) Schedule B number: 2915.39.9500
(iii) CAS number: 108-65-6
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
XII. Determination to Add Propylene
Glycol Methyl Ether to the List
The Dow Chemical Company, an
importer and exporter of propylene gly-
col methyl ether, submitted a petition
in accordance with Rev. Proc. 2022-26
requesting to add propylene glycol methyl
ether to the List. According to the petition,
the taxable chemicals propylene, chlorine,
sodium hydroxide, and methane constitute
100.00 percent by weight of the materials
used to produce propylene glycol methyl
ether, based on the predominant method of
production.
(a) Determination. Propylene glycol
methyl ether is added to the list of taxable
substances under section 4672(a). Other
pertinent information is as follows:
(1) Predominant method of production:
Glycol ethers are predominantly produced
by reacting an epoxide (typically ethylene
oxide or propylene oxide) with an alco-
hol; this reaction process is referred to
as alkoxylation. Propylene glycol methyl
ether is made via the alkoxylation process
(also known as ring opening of an epox-
ide) using methanol and propylene oxide.
Methanol is made from syngas (carbon
monoxide and dihydrogen). Carbon mon-
oxide (CO) and dihydrogen (H
2
) are made
by steam-methane reforming (CH
4
and
H
2
O). Propylene oxide is made by hydro-
chlorination (chlorine (Cl
2
), propylene
(C
3
H
6
), and sodium hydroxide (NaOH)).
Additional information on the production
process is as follows:
(i) The propylene glycol methyl ether
alkoxylation reaction (methanol + pro-
pylene oxide) is base catalyzed, using a
small amount of metal hydroxide to pro-
duce methoxide. Once methoxide is made,
it is regenerated following conversion to
the product in the presence of propylene
oxide. Regenerated methoxide in the pres-
ence of propylene oxide will perpetually
5
The Notice of Filing erroneously stated, “Since the amount of metal hydroxide used to produce propylene glycol methyl ether is very small...” This error is corrected here.

Bulletin No. 2025–34 335 August 18, 2025
react until all propylene oxide is con-
sumed or the reaction is halted through the
use of controls.
(ii) Since the amount of metal hydroxide
used to produce propylene glycol methyl
ether is very small, the metal hydroxide
has been excluded from the stoichiometric
material consumption equation; including
the metal hydroxide would lead to a dis-
torted conversion factor.
(2) Stoichiometric material consump-
tion equation:
C
3
H
6
(propylene) + Cl
2
(chlorine) +
2 NaOH (sodium hydroxide) +
CH
4
(methane) → C
4
H
10
O
2
(propylene
glycol methyl ether) + 2 NaCl (sodium
chloride) + H
2
(hydrogen)
(3) Reasons for the determination: The
propylene glycol methyl ether petition
was filed on June 13, 2024. The notice
of filing summarizing the petition and
requesting comments was published in the
Federal Register (89 FR 71784) on Sep-
tember 3, 2024. The Treasury Department
and the IRS received no written comments
in response to the notice of filing. A public
hearing was neither requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation and
other information in the petition shows
that the taxable chemicals propylene,
chlorine, sodium hydroxide, and methane
constitute more than 20 percent by weight
of the materials used in the production of
propylene glycol methyl ether, based on
the predominant method of production.
Therefore, the test in section 4672(a)(2)
(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of pro-
pylene glycol methyl ether to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Secre-
tary: $10.58 per ton. The conversion fac-
tors for the taxable chemicals used in the
production of propylene glycol methyl
ether are for 0.47 for propylene, 0.79 for
chlorine, 0.89 for sodium hydroxide, and
0.18 for methane. The tax rate is calcu-
lated by adding the products of the con-
version factor for each taxable chemical
and the tax rate for that taxable chemical:
((0.47 x $9.74) + (0.79 x $5.40) + (0.89 x
$0.56) + (0.18 x $6.88) = $10.58).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2909.49.6000
(ii) Schedule B number: 2909.49.0000
(iii) CAS number: 107-98-2
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
XIII. Determination to Add Propylene
Glycol N-Propyl Ether to the List
The Dow Chemical Company, an
importer and exporter of propylene gly-
col n-propyl ether, submitted a petition
in accordance with Rev. Proc. 2022-26
requesting to add propylene glycol n-pro-
pyl ether to the List. According to the
petition, the taxable chemicals propylene,
chlorine, sodium hydroxide, ethylene,
and methane constitute 100.00 percent by
weight of the materials used to produce
propylene glycol n-propyl ether, based on
the predominant method of production.
(a) Determination. Propylene glycol
n-propyl ether is added to the list of tax-
able substances under section 4672(a).
Other pertinent information is as follows:
(1) Predominant method of production:
Glycol ethers are predominantly produced
by reacting an epoxide (typically ethylene
oxide or propylene oxide) with an alco-
hol; this reaction process is referred to as
alkoxylation. Propylene glycol n-propyl
ether is produced via the alkoxylation
process (also known as ring opening of
an epoxide) using n-propylene and pro-
pylene oxide. Propylene oxide is made by
hydrochlorination (chlorine, propylene,
NaOH). The n-propanol is manufactured
by catalytic hydrogenation of propion-
aldehyde (hydrogen (H
2
) + propionalde-
hyde (CH
3
CH
2
CHO)). Propionaldehyde is
produced by hydroformulation of ethylene
(C
2
H
4
) using carbon monoxide (CO). The
n-propanol is made by hydrogenating pro-
pionaldehyde in the presence of a catalyst.
Additional information on the production
process is as follows:
(i) The propylene glycol n-propyl ether
alkoxylation reaction (n-propanol + pro-
pylene oxide) is base catalyzed, using a
small amount of metal hydroxide to pro-
duce methoxide. Once propoxide is made,
it is regenerated following conversion to
the product in the presence of propylene
oxide. Regenerated propoxide in the pres-
ence of propylene oxide will perpetually
react until all propylene oxide is con-
sumed or the reaction is halted through the
use of controls.
(ii) Since the amount of metal hydrox-
ide used to produce propylene glycol
n-propyl ether is very small, the metal
hydroxide has been excluded from the
stoichiometric material consumption
equation; including the metal hydroxide
would lead to a distorted conversion fac-
tor.
(2) Stoichiometric material consump-
tion equation:
C
3
H
6
(propylene) + Cl
2
(chlorine) +
2 NaOH (sodium hydroxide) + C
2
H
4

(ethylene) + CH
4
(methane) → 2 NaCl
(sodium chloride) + H
2
(hydrogen) +
C
6
H
14
O
2
(propylene glycol n-propyl
ether)
(3) Reasons for the determination:
The propylene glycol n-propyl ether
petition was filed on June 13, 2024. The
notice of filing summarizing the petition
and requesting comments was published
in the Federal Register (89 FR 71791) on
September 3, 2024. The Treasury Depart-
ment and the IRS received no written
comments in response to the notice
of filing. A public hearing was neither
requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation and
other information in the petition shows
that the taxable chemicals propylene,
chlorine, sodium hydroxide, ethylene, and
methane constitute more than 20 percent
by weight of the materials used in the
production of propylene glycol n-propyl
ether, based on the predominant method of
production. Therefore, the test in section
4672(a)(2)(B) is satisfied.

August 18, 2025 336 Bulletin No. 2025–34
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of pro-
pylene glycol n-propyl ether to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Sec-
retary: $10.43 per ton. The conversion
factors for the taxable chemicals used in
the production of propylene glycol n-pro-
pyl ether are for 0.36 for propylene, 0.60
for chlorine, 0.68 for sodium hydroxide,
0.24 for ethylene, and 0.14 for methane.
The tax rate is calculated by adding the
products of the conversion factor for each
taxable chemical and the tax rate for that
taxable chemical: ((0.36 x $9.74) + (0.60
x $5.40) + (0.68 x $0.56) + (0.24 x $9.74)
+ (0.14 x $6.88) = $10.43).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2909.49.60.00
(ii) Schedule B number: 2909.49.0000
(iii) CAS number: 1569-01-3
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
XIV. Determination to Add Propylene
Glycol Phenyl Ether to the List
The Dow Chemical Company, an
importer and exporter of propylene gly-
col phenyl ether, submitted a petition
in accordance with Rev. Proc. 2022-26
requesting to add propylene glycol phenyl
ether to the List. According to the petition,
the taxable chemicals propylene, chlorine,
sodium hydroxide, and benzene constitute
91.00 percent by weight of the materials
used to produce propylene glycol phenyl
ether, based on the predominant method of
production.
(a) Determination. Propylene glycol
phenyl ether is added to the list of taxable
substances under section 4672(a). Other
pertinent information is as follows:
(1) Predominant method of production:
Glycol ethers are predominantly produced
by reacting an epoxide (typically ethylene
oxide or propylene oxide) with an alco-
hol; this reaction process is referred to
as alkoxylation. Propylene glycol phenyl
ether is made via the alkoxylation process
(also known as ring opening of an epox-
ide) using phenol and propylene oxide.
Propylene oxide is made by hydrochlori-
nation (chlorine (Cl
2
), propylene (C
3
H
6
),
and sodium hydroxide (NaOH)). Phenol
is made via the Hock process (sometimes
called the cumene process). The Hock
process has two stages. In stage 1, ben-
zene (C
6
H
6
) is alkylated with propylene
(C
3
H
6
) to make cumene (isopropyl ben-
zene). In stage 2, cumene (C
6
H
5
(C
3
H
7
))
is partially oxidized to make phenol
(C
6
H
5
OH) and side product dimethyl
ketone ((CH
3
)
2
CHO). Additional informa-
tion on the production process is as fol-
lows:
(i) The propylene glycol phenyl ether
alkoxylation reaction (phenol + propyl-
ene oxide) is base catalyzed, using a small
amount of metal hydroxide. Once phenox-
ide is made, it is regenerated following
conversion to the product in the presence
of propylene oxide. Regenerated phenox-
ide in the presence of propylene oxide
will perpetually react until all propylene
oxide is consumed or the reaction is halted
through the use of controls.
(ii) Since the amount of metal hydrox-
ide used to produce propylene glycol phe-
nyl ether is very small, the metal hydroxide
has been excluded from the stoichiometric
material consumption equation; including
the metal hydroxide would lead to a dis-
torted conversion factor.
(2) Stoichiometric material consump-
tion equation:
2 C
3
H
6
(propylene) + Cl
2
(chlorine) +
2 NaOH (sodium hydroxide) + C
6
H
6

(benzene) + O
2
(oxygen) → 2 NaCl
(sodium chloride) + H
2
O (water)
+ (CH
3
)
2
CO (dimethyl ketone) +
C
9
H
12
O
2
(propylene glycol phenyl
ether)
(3) Reasons for the determination: The
propylene glycol phenyl ether petition
was filed on June 13, 2024. The notice
of filing summarizing the petition and
requesting comments was published in the
Federal Register (89 FR 71786) on Sep-
tember 3, 2024. The Treasury Department
and the IRS received no written comments
in response to the notice of filing. A public
hearing was neither requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation and
other information in the petition shows
that the taxable chemicals propylene,
chlorine, sodium hydroxide, and benzene
constitute more than 20 percent by weight
of the materials used in the production of
propylene glycol phenyl ether, based on
the predominant method of production.
Therefore, the test in section 4672(a)(2)
(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of pro-
pylene glycol phenyl ether to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Secre-
tary: $13.16 per ton. The conversion fac-
tors for the taxable chemicals used in the
production of propylene glycol phenyl
ether are 0.55 for propylene, 0.47 for chlo-
rine, 0.53 for sodium hydroxide, and 0.51
for benzene. The tax rate is calculated
by adding the products of the conversion
factor for each taxable chemical and the
tax rate for that taxable chemical: ((0.55 x
$9.74) + (0.47 x $5.40) + (0.53 x $0.56) +
(0.51 x $9.74) = $13.16).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2909.49.15.00
(ii) Schedule B number: 2909.49.0000
(iii) CAS number: 770-35-4
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
XV. Determination to Add Di-Isobutyl
Carbinol to the List
ALTIVIA Ketones & Additives, LLC,
an exporter of di-isobutyl carbinol, sub-
mitted a petition in accordance with Rev.

Bulletin No. 2025–34 337 August 18, 2025
Proc. 2022-26 requesting to add di-isobu-
tyl carbinol to the List. According to the
petition, the taxable chemical propylene
constitutes 87.51 percent by weight of the
materials used to produce di-isobutyl car-
binol, based on the predominant method
of production.
(a) Determination. Di-isobutyl carbinol
is added to the list of taxable substances
under section 4672(a). Other pertinent
information is as follows:
(1) Predominant method of produc-
tion: The predominant method of pro-
duction is aldol condensation of acetone.
Aldol condensation is a two-step pro-
cess in which an aldol reaction forms an
aldol product and a dehydration reaction
removes water to form the final product.
The process uses acetone in condensa-
tion, dehydration, and hydrogenation
steps. Acetone is passed over a strong
base catalyst to form diacetone alcohol,
then dehydrated to mesityl oxide, and
subsequently hydrogenated to methyl
isobutyl ketone. Generally, the pro-
cess forms co-produced methyl isobu-
tyl ketone, methyl isobutyl carbinol,
di-isobutyl ketone and, to a lesser extent,
di-isobutyl carbinol.
(2) Stoichiometric material consump-
tion equation:
3(C
3
H
6
(propylene)) + H
2
O → C
9
H
20
O
(di-isobutyl carbinol)
(3) Reasons for the determination: The
di-isobutyl carbinol petition was filed on
September 23, 2024. The notice of filing
summarizing the petition and requesting
comments was published in the Federal
Register (89 FR 94878) on November
29, 2024. The Treasury Department and
the IRS received no written comments in
response to the notice of filing. A public
hearing was neither requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation
and other information in the petition
shows that the taxable chemical propyl-
ene constitutes more than 20 percent by
weight of the materials used in the pro-
duction of di-isobutyl carbinol, based on
the predominant method of production.
Therefore, the test in section 4672(a)(2)
(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of
di-isobutyl carbinol to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): January 1, 2024
(6) Tax rate prescribed by the Secre-
tary: $8.57 per ton. The conversion factor
for the propylene used in the production of
di-isobutyl carbinol is 0.88. The tax rate is
calculated by multiplying the conversion
factor by the tax rate for propylene (0.88 x
$9.74 = $8.57).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2905.19.9090
(ii) Schedule B number: 2905.19.9095
(iii) CAS number: 108-82-7
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
XVI. Determination to Add Di-Isobutyl
Ketone to the List
ALTIVIA Ketones & Additives, LLC,
an exporter of di-isobutyl ketone, sub-
mitted a petition in accordance with Rev.
Proc. 2022-26 requesting to add di-isobutyl
ketone to the List. According to the petition,
the taxable chemical propylene constitutes
87.51 percent by weight of the materials
used to produce di-isobutyl ketone, based
on the predominant method of production.
(a) Determination. Di-isobutyl ketone
is added to the list of taxable substances
under section 4672(a). Other pertinent
information is as follows:
(1) Predominant method of production:
The predominant method of production is
aldol condensation of acetone. Aldol con-
densation is a two-step process in which
an aldol reaction forms an aldol product
and a dehydration reaction removes water
to form the final product. The process uses
acetone in condensation, dehydration, and
hydrogenation steps. Acetone is passed
over a strong base catalyst to form diac-
etone alcohol, then dehydrated to mesityl
oxide, and subsequently hydrogenated
to methyl isobutyl ketone. Generally,
the process forms co-produced methyl
isobutyl ketone, methyl isobutyl carbinol,
di-isobutyl ketone and, to a lesser extent,
di-isobutyl carbinol.
(2) Stoichiometric material consump-
tion equation:
3(C
3
H
6
(propylene)) + H
2
O → C
9
H
18
O
(di-isobutyl ketone) + H
2

(3) Reasons for the determination:
The di-isobutyl ketone petition was
filed on September 23, 2024. The notice
of filing summarizing the petition and
requesting comments was published
in the Federal Register (89 FR 94879)
on November 29, 2024. The Treasury
Department and the IRS received no
written comments in response to the
notice of filing. A public hearing was
neither requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation and
other information in the petition shows
that the taxable chemical propylene con-
stitutes more than 20 percent by weight
of the materials used in the production of
di-isobutyl ketone, based on the predomi-
nant method of production. Therefore, the
test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of
di-isobutyl ketone to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): January 1, 2024
(6) Tax rate prescribed by the Secre-
tary: $8.67 per ton. The conversion factor
for the propylene used in the production of
di-isobutyl ketone is 0.89. The tax rate is
calculated by multiplying the conversion
factor by the tax rate for propylene: (0.89
x $9.74 = $8.67).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:

August 18, 2025 338 Bulletin No. 2025–34
(i) HTSUS number: 2914.19.0000
(ii) Schedule B number: 2914.19.0000
(iii) CAS number: 108-83-8
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
XVII. Determination to Add Methyl
Isobutyl Carbinol to the List
ALTIVIA Ketones & Additives, LLC,
an exporter of methyl isobutyl carbi-
nol, submitted a petition in accordance
with Rev. Proc. 2022-26 requesting to
add methyl isobutyl carbinol to the List.
According to the petition, the taxable
chemical propylene constitutes 82.36
percent by weight of the materials used to
produce methyl isobutyl carbinol, based
on the predominant method of produc-
tion.
(a) Determination. Methyl isobutyl
carbinol is added to the list of taxable sub-
stances under section 4672(a). Other per-
tinent information is as follows:
(1) Predominant method of production:
The predominant method of production is
aldol condensation of acetone. Aldol con-
densation is a two-step process in which an
aldol reaction forms an aldol product and a
dehydration reaction removes water to form
the final product. The process uses acetone
in condensation, dehydration, and hydro-
genation steps. Acetone is passed over a
strong base catalyst to form diacetone alco-
hol, then dehydrated to mesityl oxide, and
subsequently hydrogenated to methyl isobu-
tyl ketone. Generally, the process forms
co-produced methyl isobutyl ketone, methyl
isobutyl carbinol, di-isobutyl ketone and, to
a lesser extent, di-isobutyl carbinol.
(2) Stoichiometric material consump-
tion equation:
2(C
3
H
6
(propylene)) + H
2
O → C
6
H
14
O
(methyl isobutyl carbinol)
(3) Reasons for the determination: The
methyl isobutyl carbinol petition was filed
on September 23, 2024. The notice of fil-
ing summarizing the petition and request-
ing comments was published in the Fed-
eral Register (89 FR 94877) on November
29, 2024. The Treasury Department and
the IRS received no written comments in
response to the notice of filing. A public
hearing was neither requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation and
other information in the petition shows
that the taxable chemical propylene con-
stitutes more than 20 percent by weight
of the materials used in the production
of methyl isobutyl carbinol, based on
the predominant method of production.
Therefore, the test in section 4672(a)(2)
(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of
methyl isobutyl carbinol to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): January 1, 2024
(6) Tax rate prescribed by the Secre-
tary: $7.99 per ton. The conversion factor
for the propylene used in the production
of methyl isobutyl carbinol is 0.82. The
tax rate is calculated by multiplying the
conversion factor by the tax rate for pro-
pylene: (0.82 x $9.74 = $7.99).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2905.19.9090
(ii) Schedule B number: 2905.19.9095
(iii) CAS number: 108-11-2
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
XVIII. Determination to Add Cyanuric
Acid to the List
Occidental Chemical Corporation,
an interested person in cyanuric acid,
submitted a petition in accordance with
Rev. Proc. 2022-26 requesting to add
cyanuric acid to the List. According
to the petition, the taxable chemical
ammonia constitutes 27.90 percent by
weight of the materials used to produce
cyanuric acid, based on the predominant
method of production.
(a) Determination. Cyanuric acid is
added to the list of taxable substances
under section 4672(a). Other pertinent
information is as follows:
(1) Predominant method of production:
The predominant process for the manufac-
ture of cyanuric acid is using urea thermal
decomposition to produce cyanuric acid.
(2) Stoichiometric material consump-
tion equation:
3 NH
3
(ammonia) + 3 CO
2
(carbon
dioxide) → C
3
N
3
O
3
H
3
(cyanuric acid)
+
3 H
2
O (water)
(3) Reasons for the determination:
The cyanuric acid petition was filed on
November 25, 2024. The notice of filing
summarizing the petition and requesting
comments was published in the Federal
Register (90 FR 7246) on January 21,
2025. The Treasury Department and the
IRS received one written comment, dis-
cussed below, in response to the notice
of filing. A public hearing was neither
requested nor held.
The commenter asserts that the notice
did not give a reason to add the sub-
stance to the List and inquires “[w]hy
would a long-term product be added...if
it’s already in production at a chemical
plant for distribution.” It is not clear to the
Treasury Department and the IRS what
is the significance of a “long-term prod-
uct.” Regardless, the commenter did not
demonstrate that cyanuric acid does not
meet the weight or value test under sec-
tion 4672(a)(2)(B). Under section 4672(a)
(2)(b) and (4) and (b)(2), the Secretary is
required to add a substance to the List if
the Secretary determines that any taxable
chemicals used to produce the substance
meet the weight or value test. The petition
represented and the Secretary determined
that a taxable chemical constitutes more
than 20 percent by weight of the mate-
rials used in the production of cyanuric
acid, based on the predominant method of
production. For this reason, the Treasury
Department and the IRS decline to adopt
any change to this determination based on
the public comment.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation
and other information in the petition
shows that the taxable chemical ammo-

Bulletin No. 2025–34 339 August 18, 2025
nia constitutes more than 20 percent
by weight of the materials used in the
production of cyanuric acid, based on
the predominant method of production.
Therefore, the test in section 4672(a)(2)
(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of
cyanuric acid to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): October 1, 2024
(6) Tax rate prescribed by the Secre-
tary: $2.11 per ton. The conversion factor
for the ammonia used in the production of
cyanuric acid is 0.40. The tax rate is calcu-
lated by multiplying the conversion factor
by the tax rate for ammonia: (0.40 x $5.28
= $2.11).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2933.69.6050
(ii) Schedule B number: 2933.69.0000
(iii) CAS number: 108-80-5
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
XIX. Determination to Add Potassium
Bicarbonate to the List
Occidental Chemical Corporation, an
exporter of potassium bicarbonate, sub-
mitted a petition in accordance with Rev.
Proc. 2022-26 requesting to add potas-
sium bicarbonate to the List. According
to the petition, the taxable chemical potas-
sium hydroxide constitutes 56.04 percent
by weight of the materials used to produce
potassium bicarbonate, based on the pre-
dominant method of production.
(a) Determination. Potassium bicar-
bonate is added to the list of taxable sub-
stances under section 4672(a). Other per-
tinent information is as follows:
(1) Predominant method of produc-
tion: The predominant process for the
manufacture of potassium bicarbonate is
absorption of CO
2
with potassium hydrox-
ide. The predominant process for carbon-
ate manufacture is absorption of CO
2
with
alkaline liquid. This substance is produced
as a pure component, not a mixture.
(2) Stoichiometric material consump-
tion equation:
CO
2
(carbon dioxide) + KOH
(potassium hydroxide) → HKCO
3

(potassium bicarbonate)
(3) Reasons for the determination: The
potassium bicarbonate petition was filed
on November 25, 2024. The notice of fil-
ing summarizing the petition and request-
ing comments was published in the Fed-
eral Register (90 FR 7245) on January
21, 2025. The Treasury Department and
the IRS received no written comments in
response to the notice of filing. A public
hearing was neither requested nor held.
The Secretary followed the process in
section 4672(a)(2)(B) in making this deter-
mination. A review of the stoichiometric
material consumption equation and other
information in the petition shows that the
taxable chemical potassium hydroxide
constitutes more than 20 percent by weight
of the materials used in the production of
potassium bicarbonate, based on the pre-
dominant method of production. Therefore,
the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of
potassium bicarbonate to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Secre-
tary: $0.25 per ton. The conversion fac-
tor for the potassium hydroxide used in
the production of potassium bicarbon-
ate is 0.56. The tax rate is calculated by
multiplying the conversion factor by the
tax rate for potassium hydroxide: (0.56 x
$0.44 = $0.25).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2836.40.2000
(ii) Schedule B number: 2836.40.0000
(iii) CAS number: 298-14-6
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
XX. Determination to Add Potassium
Carbonate to the List
Occidental Chemical Corporation, an
exporter of potassium carbonate, submit-
ted a petition in accordance with Rev.
Proc. 2022-26 requesting to add potas-
sium carbonate to the List. According to
the petition, the taxable chemical potas-
sium hydroxide constitutes 71.83 percent
by weight of the materials used to produce
potassium carbonate, based on the pre-
dominant method of production.
(a) Determination. Potassium carbon-
ate is added to the list of taxable sub-
stances under section 4672(a). Other per-
tinent information is as follows:
(1) Predominant method of production:
The predominant process for the manufac-
ture of potassium carbonate is absorption of
CO
2
with KOH. The predominant process for
carbonate manufacture is absorption of CO
2

with alkaline liquid. This substance is pro-
duced as a pure component, not a mixture.
(2) Stoichiometric material consump-
tion equation:
CO
2
(carbon dioxide) + 2 KOH
(potassium hydroxide) → K
2
CO
3

(potassium carbonate) + H
2
O (water)
(3) Reasons for the determination: The
potassium carbonate petition was filed on
November 25, 2024. The notice of filing
summarizing the petition and requesting
comments was published in the Federal
Register (90 FR 7247) on January 21,
2025. The Treasury Department and the
IRS received two written comments, dis-
cussed below, in response to the notice
of filing. A public hearing was neither
requested nor held.
One public comment asserted that
potassium carbonate does “not pose
any significant health or environmental
risks,” objected to the weight or value
test of section 4672(a)(2)(B), and urged
the Secretary to exercise discretion when
determining whether a substance poses a
significant danger that warrants imposing
the tax under section 4671. Another pub-

August 18, 2025 340 Bulletin No. 2025–34
lic comment inquired about the effects
of potassium carbonate and asserted that
“[t]he most important thing is to avoid
any type of exposure to the chemical as it
can cause severe damage.” Neither com-
ment demonstrated whether potassium
carbonate meets the weight or value test
under section 4672(a)(2)(B). Under sec-
tion 4672(a)(2)(b) and (4) and (b)(2), the
Secretary is required to add a substance
to the List if the Secretary determines
that any taxable chemicals used to pro-
duce the substance meet the weight or
value test. Congress did not give the Sec-
retary discretion to determine whether
a substance poses significant health or
environmental risks or otherwise poses
a significant danger. The petition rep-
resented and the Secretary determined
that a taxable chemical constitutes more
than 20 percent by weight of the materi-
als used in the production of potassium
carbonate, based on the predominant
method of production. For this reason,
the Treasury Department and the IRS
decline to adopt the suggestions of these
public comments.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation and
other information in the petition shows
that the taxable chemical potassium
hydroxide constitutes more than 20 per-
cent by weight of the materials used in the
production of potassium carbonate, based
on the predominant method of production.
Therefore, the test in section 4672(a)(2)
(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of
potassium carbonate to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Secre-
tary: $0.36 per ton. The conversion factor
for the potassium hydroxide used in the
production of potassium carbonate is 0.81.
The tax rate is calculated by multiplying
the conversion factor by the tax rate for
potassium hydroxide: (0.81 x $0.44 =
$0.36).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2836.40.1000
(ii) Schedule B number: 2836.40.0000
(iii) CAS number: 584-08-7
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
XXI. Determination to Add Sodium
Chlorite to the List
Occidental Chemical Corporation, an
exporter of sodium chlorite, submitted
a petition in accordance with Rev. Proc.
2022-26 requesting to add sodium chlorite
to the List. According to the petition, the
taxable chemicals chlorine and sodium
hydroxide constitute 75.87 percent by
weight of the materials used to produce
sodium chlorite, based on the predomi-
nant method of production.
(a) Determination. Sodium chlorite
is added to the list of taxable substances
under section 4672(a). Other pertinent
information is as follows:
(1) Predominant method of produc-
tion: The predominant process for the
manufacture of sodium chlorite is elec-
trolytic production of NaClO
3
followed
by hydrochlorination with wet acid with
byproduct chlorine and hydrogen used in
the manufacture of acid. This substance is
produced as a pure component, not a mix-
ture, though it may be sold as an aqueous
liquid.
(2) Stoichiometric material consump-
tion equation:
2 Cl
2
(chlorine) + 4 NaOH (sodium
hydroxide) + 3 O
2
(oxygen) →
4 NaClO
2
(sodium chlorite) +
2 H
2
O (water)
(3) Reasons for the determination:
The sodium chlorite petition was filed
on November 25, 2024. The notice of
filing summarizing the petition and
requesting comments was published in
the Federal Register (90 FR 7247) on
January 21, 2025. The Treasury Depart-
ment and the IRS received no written
comments in response to the notice of
filing. A public hearing was neither
requested nor held.
The Secretary followed the process
in section 4672(a)(2)(B) in making this
determination. A review of the stoichio-
metric material consumption equation and
other information in the petition shows
that the taxable chemicals chlorine and
sodium hydroxide constitute more than 20
percent by weight of the materials used in
the production of sodium chlorite, based
on the predominant method of production.
Therefore, the test in section 4672(a)(2)
(B) is satisfied.
(4) Date of determination: August 1,
2025.
(5) Effective dates for addition of
sodium chlorite to the List:
(i) Effective date for purposes of the
section 4671 tax (see section 11.01 of Rev.
Proc. 2022-26): January 1, 2026
(ii) Effective date for purposes of refund
claims under section 4662(e) (see sections
11.02 and 11.03 of Rev. Proc. 2022-26, as
modified by section 3 of Rev. Proc. 2023-
20): July 1, 2022
(6) Tax rate prescribed by the Secre-
tary: $2.35 per ton. The conversion fac-
tors for the taxable chemicals used in the
production of sodium chlorite are 0.39 for
chlorine and 0.44 for sodium hydroxide.
The tax rate is calculated by adding the
products of the conversion factor for each
taxable chemical and the tax rate for that
taxable chemical: (0.39 x $5.40 + 0.44 x
$0.56 = $2.35).
(b) Classification numbers.
(1) The Secretary has no basis to object
to the following proposed classification
numbers:
(i) HTSUS number: 2828.90.0000
(ii) Schedule B number: 2828.90.0000
(iii) CAS number: 7758-19-2
(2) The Secretary is unable to con-
firm the following proposed classification
numbers: Not applicable.
Correction to the List of Taxable
Substances
Section 4 of Notice 2021-66 includes
in the initial list of taxable substances
the taxable substance “sodium nitri-
olotriacetate monohydrate.” There is
a typographical error in the spelling
of this taxable substance. The cor-
rect name of this taxable substance

Bulletin No. 2025–34 341 August 18, 2025
is “sodium nitrilotriacetate monohy-
drate.” The tax rate for sodium nitri-
lotriacetate monohydrate was not pre-
viously provided by the Secretary. The
tax rate prescribed by the Secretary for
sodium nitrilotriacetate monohydrate is
$3.97 per ton. The conversion factors
for the taxable chemicals used in the
production of sodium nitrilotriacetate
monohydrate are 0.25 for ammonia,
0.35 for methane, and 0.44 for sodium
hydroxide. The tax rate is calculated by
adding the products of the conversion
factor for each taxable chemical and
the tax rate for that taxable chemical:
((0.25 x $5.28) + (0.35 x $6.88) + (0.44
x $0.56) = $3.97). This tax rate is effec-
tive July 1, 2022.
Effect on Other Documents
Section 4 of Notice 2021-66 is modi-
fied by replacing the name “sodium nitri-
olotriacetate monohydrate” with “sodium
nitrilotriacetate monohydrate.”
Krishna P. Vallabhaneni,
Tax Legislative Counsel.

Bulletin No. 2025–34 i August 18, 2025
Definition of Terms
Revenue rulings and revenue procedures
(hereinafter referred to as “rulings”) that
have an effect on previous rulings use the
following defined terms to describe the
effect:
Amplified describes a situation where
no change is being made in a prior pub-
lished position, but the prior position is
being extended to apply to a variation of
the fact situation set forth therein. Thus,
if an earlier ruling held that a principle
applied to A, and the new ruling holds that
the same principle also applies to B, the
earlier ruling is amplified. (Compare with
modified, below).
Clarified is used in those instances
where the language in a prior ruling is
being made clear because the language
has caused, or may cause, some confu-
sion. It is not used where a position in a
prior ruling is being changed.
Distinguished describes a situation
where a ruling mentions a previously pub-
lished ruling and points out an essential
difference between them.
Modified is used where the substance
of a previously published position is being
changed. Thus, if a prior ruling held that a
principle applied to A but not to B, and the
new ruling holds that it applies to both A
and B, the prior ruling is modified because
it corrects a published position. (Compare
with amplified and clarified, above).
Obsoleted describes a previously pub-
lished ruling that is not considered deter-
minative with respect to future transactions.
This term is most commonly used in a ruling
that lists previously published rulings that
are obsoleted because of changes in laws or
regulations. A ruling may also be obsoleted
because the substance has been included in
regulations subsequently adopted.
Revoked describes situations where the
position in the previously published ruling
is not correct and the correct position is
being stated in a new ruling.
Superseded describes a situation where
the new ruling does nothing more than
restate the substance and situation of a
previously published ruling (or rulings).
Thus, the term is used to republish under
the 1986 Code and regulations the same
position published under the 1939 Code
and regulations. The term is also used
when it is desired to republish in a single
ruling a series of situations, names, etc.,
that were previously published over a
period of time in separate rulings. If the
new ruling does more than restate the sub-
stance of a prior ruling, a combination of
terms is used. For example, modified and
superseded describes a situation where the
substance of a previously published ruling
is being changed in part and is continued
without change in part and it is desired to
restate the valid portion of the previously
published ruling in a new ruling that is
self contained. In this case, the previously
published ruling is first modified and then,
as modified, is superseded.
Supplemented is used in situations in
which a list, such as a list of the names of
countries, is published in a ruling and that
list is expanded by adding further names
in subsequent rulings. After the original
ruling has been supplemented several
times, a new ruling may be published that
includes the list in the original ruling and
the additions, and supersedes all prior rul-
ings in the series.
Suspended is used in rare situations
to show that the previous published rul-
ings will not be applied pending some
future action such as the issuance of new
or amended regulations, the outcome of
cases in litigation, or the outcome of a
Service study.
Abbreviations
The following abbreviations in current
use and formerly used will appear in
material published in the Bulletin.
A—Individual.
Acq.—Acquiescence.
B—Individual.
BE—Beneficiary.
BK—Bank.
B.T.A.—Board of Tax Appeals.
C—Individual.
C.B.—Cumulative Bulletin.
CFR—Code of Federal Regulations.
CI—City.
COOP—Cooperative.
Ct.D.
—Court Decision.
CY—County.
D—Decedent.
DC—Dummy Corporation.
DE—Donee.
Del. Order—Delegation Order.
DISC—Domestic International Sales Corporation.
DR—Donor.
E—Estate.
EE—Employee.
E.O.—Executive Order.
ER—Employer.
ERISA—Employee Retirement Income Security Act.
EX—Executor.
F—Fiduciary.
FC—Foreign Country.
FICA—Federal Insurance Contributions Act.
FISC—Foreign International Sales Company.
FPH—Foreign Personal Holding Company.
F.R.—Federal Register.
FUTA—Federal Unemployment Tax Act.
FX—Foreign corporation.
G.C.M.—Chief Counsel’s Memorandum.
GE—Grantee.
GP—General Partner.
GR—Grantor.
IC—Insurance Company.
I.R.B.—Internal Revenue Bulletin.
LE—Lessee.
LP—Limited Partner.
LR—Lessor.
M—Minor.
Nonacq.—Nonacquiescence.
O—Organization.
P—Parent Corporation.
PHC—Personal Holding Company.
PO—Possession of the U.S.
PR—Partner.
PRS—Partnership.
PTE—Prohibited Transaction Exemption.
Pub. L.—Public Law.
REIT—Real Estate Investment Trust.
Rev. Proc.—Revenue Procedure.
Rev. Rul.—Revenue Ruling.
S—Subsidiary.
S.P.R.—Statement of Procedural Rules.
Stat.—Statutes at Large.
T—Target Corporation.
T.C.—Tax Court.
T.D.—Treasury Decision.
TFE—Transferee.
TFR—Transferor.
T.I.R.—Technical Information Release.
TP—Taxpayer.
TR—Trust.
TT—Trustee.
U.S.C.—United States Code.
X—Corporation.
Y—Corporation.
Z—Corporation.

August 18, 2025 ii Bulletin No. 2025–34
Numerical Finding List
1
Bulletin 2025–34
Announcements:
2025-19, 2025-29 I.R.B. 191
2025-20, 2025-31 I.R.B. 271
2025-21, 2025-32 I.R.B. 312
Notices:
2025-32, 2025-27 I.R.B. 1
2025-33, 2025-27 I.R.B. 4
2025-34, 2025-27 I.R.B. 6
2025-35, 2025-27 I.R.B. 8
2025-31, 2025-28 I.R.B. 14
2025-36, 2025-30 I.R.B. 192
2025-37, 2025-30 I.R.B. 198
2025-40, 2025-31 I.R.B. 266
2025-39, 2025-32 I.R.B. 308
2025-28, 2025-34 I.R.B. 316
2025-41, 2025-34 I.R.B. 325
Proposed Regulations:
REG-125710-18, 2025-30 I.R.B. 263
REG-107459-24, 2025-32 I.R.B. 313
Revenue Procedures:
2025-22, 2025-30 I.R.B. 200
2025-24, 2025-31 I.R.B. 273
2025-25, 2025-32 I.R.B. 311
2025-26, 2025-33 I.R.B. 315
Revenue Rulings:
2025-13, 2025-28 I.R.B. 11
2025-14, 2025-32 I.R.B. 300
2025-15, 2025-32 I.R.B. 302
Treasury Decisions:
10021, 2025-31 I.R.B. 264
10031, 2025-32 I.R.B. 304
1
A cumulative list of all revenue rulings, revenue procedures, Treasury decisions, etc., published in Internal Revenue Bulletins 2025–27 through 2025–52 is in Internal Revenue Bulletin
2025–52, dated December 22, 2025.

Bulletin No. 2025–34 iii August 18, 2025
Finding List of Current Actions on
Previously Published Items
1
Bulletin 2025–34
1
A cumulative list of all revenue rulings, revenue procedures, Treasury decisions, etc., published in Internal Revenue Bulletins 2025–27 through 2025–52 is in Internal Revenue Bulletin
2025–52, dated December 22, 2025.

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