Notice2025-17975
Superfund Tax on Chemical Substances; Notice of Determinations To Add Substances to List of Taxable Substances
Primary source
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Published
September 17, 2025
Effective
January 1, 2026
Issuing agencies
Treasury DepartmentInternal Revenue Service
Abstract
This notice of determinations modifies the list of taxable substances to include the following 39 substances: acrylonitrile- butadiene rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>n</INF>- (C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=13.44, m=25.54), bromo- isobutene-isoprene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>- (C<INF>5</INF>H<INF>7.5</INF>Br<INF>0.5</INF>)<INF>m</INF>; n=98.20, m=1.80), chloroprene rubber, ethylene-propylene-ethylidene norbornene rubber ((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>- (C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>(C<INF>9</INF>H<INF>12</INF>)<INF>o</INF> ; m=56.82, n=40.46, o=2.71), ethylene vinyl acetate (VA < 50%) ((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>- (C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=78.95, m=21.05), ethylene vinyl acetate (VA >= 50%) ((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>- (C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=75.42, m=24.58), hydrogenated acrylonitrile-butadiene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>- (C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=22.28, m=38.86), isobutene-isoprene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>- (C<INF>5</INF>H<INF>8</INF>)<INF>m</INF>; n=99.10, m=0.90), poly(ethylene-propylene) rubber ((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>- (C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>; m=59.04, n=40.96), emulsion styrene-butadiene rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>- (C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=15.83, n=2.53), solution styrene-butadiene rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>- (C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=67.16, n=32.85), emulsion styrene butadiene rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>- (C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=14.14, n=2.26), solution styrene-butadiene rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>- (C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=13.31, n=2.50), hydrogenated acrylonitrile-butadiene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>- (C<INF>3</INF>H<INF>3</INF>N)<INF>y</INF>- (C<INF>15</INF>H<INF>24</INF>O)<INF>a</INF>; x=2,783.05, y=1,907.27, a=5.74), bromobutyl isobutylene isoprene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF> (Br<INF>2</INF>)<INF>z</INF>; x=7071, y=59, z=50), chlorobutyl isobutylene isoprene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF> (Cl<INF>2</INF>)<INF>z</INF>); x=7036, y=88, z=70), DIPE-di-isopropyl ether, di-isodecyl phthalate, di-isononyl adipate, di-isononyl phthalate, di-tridecyl phthalate, ethylene propylene diene (EPDM) rubber ((C<INF>2</INF>H<INF>4</INF>)<INF>x</INF>(C<INF>3</INF>H<INF>6</INF>)<INF>y</INF> (C<INF>9</INF>H<INF>12</INF>)<INF>z</INF>; x=5134, y=2250, z=98), isodecyl alcohol, isodecyl benzoate, isooctyl alcohol, linear nonyl phthalate, linear nonyl undecyl phthalate, linear undecyl phthalate, linear nonyl tri-mellitate, neo decanoic acid, neo pentanoic acid, nonene, regular butyl rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF> ; x=7036, y=88), tridecyl alcohol, tri-isononyl tri-mellitate, di- isobutylene, polyisobutylene, styrene-acrylonitrile ((C<INF>3</INF>H<INF>3</INF>N)<INF>a</INF>- (C<INF>8</INF>H<INF>8</INF>)<INF>s</INF>; a=0.26, s=0.74), and acrylonitrile butadiene styrene ((C<INF>3</INF>H<INF>3</INF>N)<INF>a</INF>- (C<INF>4</INF>H<INF>6</INF>)<INF>b</INF>- (C<INF>8</INF>H<INF>8</INF>)<INF>s</INF>; a=0.16, b=0.10, s=0.74),
Full Text
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[Federal Register Volume 90, Number 178 (Wednesday, September 17, 2025)]
[Notices]
[Pages 44881-44904]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-17975]
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DEPARTMENT OF THE TREASURY
Internal Revenue Service
Superfund Tax on Chemical Substances; Notice of Determinations To
Add Substances to List of Taxable Substances
AGENCY: Internal Revenue Service (IRS), Treasury.
ACTION: Notice of determinations.
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SUMMARY: This notice of determinations modifies the list of taxable
substances to include the following 39 substances: acrylonitrile-
butadiene rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=13.44, m=25.54), bromo-
isobutene-isoprene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>7.5</INF>Br<INF>0.5</INF>)<INF>m</INF>; n=98.20,
m=1.80), chloroprene rubber, ethylene-propylene-ethylidene norbornene
rubber ((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>(C<INF>9</INF>H<INF>12</INF>)<INF>o</INF>
; m=56.82, n=40.46, o=2.71), ethylene vinyl acetate (VA < 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=78.95,
m=21.05), ethylene vinyl acetate (VA >= 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=75.42,
m=24.58), hydrogenated acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=22.28, m=38.86),
isobutene-isoprene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>8</INF>)<INF>m</INF>; n=99.10, m=0.90),
poly(ethylene-propylene) rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>; m=59.04, n=40.96), emulsion
styrene-butadiene rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=15.83, n=2.53), solution
styrene-butadiene rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=67.16, n=32.85), emulsion
styrene butadiene rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=14.14, n=2.26), solution
styrene-butadiene rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=13.31, n=2.50),
hydrogenated acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>y</INF>-
(C<INF>15</INF>H<INF>24</INF>O)<INF>a</INF>; x=2,783.05, y=1,907.27,
a=5.74), bromobutyl isobutylene isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
(Br<INF>2</INF>)<INF>z</INF>; x=7071, y=59, z=50), chlorobutyl
isobutylene isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
(Cl<INF>2</INF>)<INF>z</INF>); x=7036, y=88, z=70), DIPE-di-isopropyl
ether, di-isodecyl phthalate, di-isononyl adipate, di-isononyl
phthalate, di-tridecyl phthalate, ethylene propylene diene (EPDM)
rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>x</INF>(C<INF>3</INF>H<INF>6</INF>)<INF>y</INF>
(C<INF>9</INF>H<INF>12</INF>)<INF>z</INF>; x=5134, y=2250, z=98),
isodecyl alcohol, isodecyl benzoate, isooctyl alcohol, linear nonyl
phthalate, linear nonyl undecyl phthalate, linear undecyl phthalate,
linear nonyl tri-mellitate, neo decanoic acid, neo pentanoic acid,
nonene, regular butyl rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
; x=7036, y=88), tridecyl alcohol, tri-isononyl tri-mellitate, di-
isobutylene, polyisobutylene, styrene-acrylonitrile
((C<INF>3</INF>H<INF>3</INF>N)<INF>a</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>s</INF>; a=0.26, s=0.74), and
acrylonitrile butadiene styrene
((C<INF>3</INF>H<INF>3</INF>N)<INF>a</INF>-
(C<INF>4</INF>H<INF>6</INF>)<INF>b</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>s</INF>; a=0.16, b=0.10, s=0.74),
[[Page 44882]]
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
substances added to the list, see the determination for each substance.
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 4671 tax).
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 Secretary 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 (a)(4) and (b)(2), the
Secretary is required to add a substance to the List if the Secretary
determines that any taxable 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 substance 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 initial 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. On May 31, 2024, the Secretary published a Notice of
Determination in the Federal Register (89 FR 47238) adding
polyoxymethylene to the List; this Notice of Determination was also
published in the Internal Revenue Bulletin as Notice 2024-50 (2024-26
I.R.B. 1789). On August 4, 2025, the Secretary published a Notice of
Determinations in the Federal Register (90 FR 36520) adding 21
substances to the List; this Notice of Determinations was also
published in the Internal Revenue Bulletin as Notice 2025-41 (2025-34
I.R.B. 325). Rev. Proc. 2022-26 (2022-29 I.R.B. 90), as modified by
Rev. Proc. 2023-20 (2023-15 I.R.B. 636), provides the exclusive
procedures by which an importer, exporter, or interested person may
request a determination that a particular substance be added to or
removed from the List.
Section 4671(b)(3) authorizes the Secretary to prescribe a tax rate
for taxable substances in lieu of the tax rate specified in section
4671(b)(2). The tax rate prescribed by the Secretary for a substance
added to the List is calculated by multiplying 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 production of the
substance. See sections 8 and 10.04(8) of Rev. Proc. 2022-26. Importers
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 determinations
modifies the List to include the 39 additional taxable substances
listed in the Summary of Determinations section of this notice, as
explained in the Requests to Add Substances to the List and General
Explanation of Determinations sections of this notice. The
determination for each specific substance added to the List is
explained in parts 1 through 39 of the Modifications to the List of
Taxable Substances section of this notice.
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 September 16, 2025, the Secretary determined to add the
following substances to the List:
1. Acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=13.44, m=25.54)
2. Bromo-isobutene-isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>7.5</INF>Br<INF>0.5</INF>)<INF>m</INF>; n=98.20,
m=1.80)
3. Chloroprene rubber
4. Ethylene-propylene-ethylidene norbornene rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>(C<INF>9</INF>H<INF>12</INF>)<INF>o</INF>
; m=56.82, n=40.46, o=2.71)
5. Ethylene vinyl acetate (VA < 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=78.95,
m=21.05)
6. Ethylene vinyl acetate (VA >= 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=75.42,
m=24.58)
7. Hydrogenated acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=22.28, m= 38.86)
8. Isobutene-isoprene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>8</INF>)<INF>m</INF>; n=99.10, m=0.90)
9. Poly(ethylene-propylene) rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>; m=59.04, n=40.96)
10. Emulsion styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=15.83, n=2.53)
11. Solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=67.16, n=32.85)
12. Emulsion styrene butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=14.14, n=2.26)
13. Solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=13.31, n=2.50)
14. Hydrogenated acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>y</INF>-
(C<INF>15</INF>H<INF>24</INF>O)<INF>a</INF>; x=2,783.05, y=1,907.27,
a=5.74)
15. Bromobutyl isobutylene isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
(Br<INF>2</INF>)<INF>z</INF>; x=7071, y=59, z=50)
16. Chlorobutyl isobutylene isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
(Cl<INF>2</INF>)<INF>z</INF>); x=7036, y=88, z=70)
17. DIPE-di-isopropyl ether
18. Di-isodecyl phthalate
19. Di-isononyl adipate
20. Di-isononyl phthalate
21. Di-tridecyl phthalate
22. Ethylene propylene diene (EPDM) rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>x</INF>(C<INF>3</INF>H<INF>6</INF>)<INF>y</INF>
(C<INF>9</INF>H<INF>12</INF>)<INF>z</INF>; x=5134, y=2250, z=98)
23. Isodecyl alcohol
24. Isodecyl benzoate
25. Isooctyl alcohol
26. Linear nonyl phthalate
27. Linear nonyl undecyl phthalate
28. Linear undecyl phthalate
29. Linear nonyl tri-mellitate
30. Neo decanoic acid
31. Neo pentanoic acid
32. Nonene
33. Regular butyl rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
; x=7036, y=88)
34. Tridecyl alcohol
35. Tri-isononyl tri-mellitate
36. Di-isobutylene
37. Polyisobutylene
38. Styrene-acrylonitrile ((C<INF>3</INF>H<INF>3</INF>N)<INF>a</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>s</INF>; a=0.26, s=0.74)
39. Acrylonitrile butadiene styrene
((C<INF>3</INF>H<INF>3</INF>N)<INF>a</INF>-
(C<INF>4</INF>H<INF>6</INF>)<INF>b</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>s</INF>; a=0.16, b=0.10, s=0.74)
Requests To Add Substances to the List
For each of the substances listed in the Summary of Determinations
section of this notice, an importer or an exporter 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 petition represented that taxable
chemicals constitute more than 20
[[Page 44883]]
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 chemicals 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 accordance 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 determinations included in parts 1 through 39 of the
Modifications to the List of Taxable Substances 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. All scientific information provided in the specific
determinations reflects the information provided by petitioners as
published in each taxable substance's respective Notice of Filing.
Classification numbers proposed by each petitioner are included in
paragraph (b) of each part, after each specific determination. The
classification numbers provided with respect to a taxable substance 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) identification of
a substance as a taxable substance 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 1 through 39 of the Modifications to the List of Taxable
Substances 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 determination in paragraph (a)(5)(ii)
of each of parts 1 through 39 of the Modifications to the List of
Taxable Substances section of this notice.
Modifications to the List of Taxable Substances
1. Determination To Add Acrylonitrile-butadiene Rubber ((C4H6)n-
(C3H3N)m; n=13.44, m=25.54) to the List
Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters
of acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=13.44, m=25.54), submitted
a petition in accordance with Rev. Proc. 2022-26 requesting to add
acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=13.44, m=25.54) to the
List. According to the petition, the taxable chemicals butadiene,
propylene, and ammonia constitute 64.59 percent by weight of the
materials used to produce acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=13.44, m=25.54), based on
the predominant method of production.
(a) Determination. Acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=13.44, m=25.54) 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
producing acrylonitrile-butadiene rubber is through a radical
polymerization of acrylonitrile and butadiene in an emulsion process.
Acrylonitrile monomer is produced by the SOHIO process (i.e., catalytic
ammoxidation of propylene).
(2) Stoichiometric material consumption equation:
n C<INF>4</INF>H<INF>6</INF> (butadiene) + m
[C<INF>3</INF>H<INF>6</INF> (propylene) + NH<INF>3</INF> (ammonia) + 3/
2 O<INF>2</INF>] [rarr] (C<INF>4</INF>H<INF>6</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF> (acrylonitrile-butadiene
rubber) + 3m H<INF>2</INF>O
(3) Reasons for the determination: The acrylonitrile-butadiene
rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=13.44, m=25.54) petition
was filed on February 7, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 14684) on April 3, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals butadiene, propylene, and ammonia constitute more
than 20 percent by weight of the materials used in the production of
acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=13.44, m=25.54), based on
the predominant method of production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of acrylonitrile-butadiene rubber
((C4H6)n-(C3H3N)m; n=13.44, m=25.54) 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: $9.58 per ton. The
conversion factors for the taxable chemicals used in the production of
acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=13.44, m=25.54) are 0.35
for butadiene, 0.52 for propylene, and 0.21 for ammonia. The tax rate
is calculated by adding the products of the conversion factor for each
taxable chemical by the tax rate for that taxable chemical: ((0.35 x
$9.74) + (0.52 x $9.74) + (0.21 x $5.28) = $9.58).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 4002.59.0000.
(ii) Schedule B number: 4002.59.0000.
(iii) CAS number: 9003-18-3.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
2. Determination To Add Bromo-isobutene-isoprene Rubber ((C4H8)n-
(C5H7.5Br0.5)m; n=98.20, m=1.80) to the List
Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters
of bromo-isobutene-isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>7.5</INF>Br<INF>0.5</INF>)<INF>m</INF>; n=98.20,
m=1.80), submitted a petition in accordance with Rev. Proc. 2022-26
requesting to add bromo-isobutene-isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>7.5</INF>Br<INF>0.5</INF>)<INF>m</INF>; n=98.20,
m=1.80) to the List. According to the petition, the taxable chemicals
butylene, bromine, and sodium hydroxide constitute 97.89 percent by
weight of the materials used to produce bromo-isobutene-isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>7.5</INF>Br<INF>0.5</INF>)<INF>m</INF>; n=98.20,
m=1.80), based on the predominant method of production.
(a) Determination. Bromo-isobutene-isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>7.5</INF>Br<INF>0.5</INF>)<INF>m</INF>; n=98.20,
m=1.80) 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
producing bromo-isobutene-isoprene
[[Page 44884]]
rubber involves reacting a hexane solution of butyl rubber with
elemental bromine. Butyl rubber is produced via the cationic
copolymerization of butylene with isoprene in the presence of a
Friedel-Crafts catalyst at low temperature, around -100 [deg]C.
(2) Stoichiometric material consumption equation:
n C<INF>4</INF>H<INF>8</INF> (butylene) + m C<INF>5</INF>H<INF>8</INF>
(isoprene) + m/2 Br<INF>2</INF> (bromine) + m/2 NaOH
(sodium hydroxide) [rarr] (C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>
(C<INF>5</INF>H<INF>7.5</INF>Br<INF>0.5</INF>)<INF>m</INF> (bromo-
isobutene-isoprene rubber) + m/2 NaBr + m/2 H<INF>2</INF>O
(3) Reasons for the determination: The bromo-isobutene-isoprene
rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>7.5</INF>Br<INF>0.5</INF>)<INF>m</INF>; n=98.20,
m=1.80) petition was filed on February 7, 2025. The notice of filing
summarizing the petition and requesting comments was published in the
Federal Register (90 FR 14694) on April 3, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals butylene, bromine, and sodium hydroxide
constitute more than 20 percent by weight of the materials used in the
production of bromo-isobutene-isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>7.5</INF>Br<INF>0.5</INF>)<INF>m</INF>; n=98.20,
m=1.80), based on the predominant method of production. Therefore, the
test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of bromo-isobutene-isoprene rubber
((C4H8)n-(C5H7.5Br0.5)m; n=98.20, m=1.80) 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 Secretary: $9.72 per ton. The
conversion factors for the taxable chemicals used in the production of
bromo-isobutene-isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>7.5</INF>Br<INF>0.5</INF>)<INF>m</INF>; n=98.20,
m=1.80) are 0.97 for butylene, 0.03 for bromine, and 0.01 for sodium
hydroxide. The tax rate is calculated by adding the products of the
conversion factor for each taxable chemical by the tax rate for that
taxable chemical: ((0.97 x $9.74) + (0.03 x $8.90) + (0.01 x $0.56) =
$9.72).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 4002.39.0000.
(ii) Schedule B number: 4002.39.0000.
(iii) CAS number: 68441-14-5.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
3. Determination To Add Chloroprene Rubber to the List
Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters
of chloroprene rubber, submitted a petition in accordance with Rev.
Proc. 2022-26 requesting to add chloroprene rubber to the List.
According to the petition, the taxable chemicals butadiene, chlorine,
and sodium hydroxide constitute 100 percent by weight of the materials
used to produce chloroprene rubber, based on the predominant method of
production.
(a) Determination. Chloroprene rubber 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
producing chloroprene rubber is through polymerization of chloroprene
initiated by a radical initiator in an emulsion process. Chloroprene
monomer is made from butadiene by first reacting it with chlorine in
the gas phase at ca 500 K to form 3,4-dichlorobut-1-ene and 1,4-
dichlorobut-2-ene. The former, on reaction with sodium hydroxide,
yields chloroprene monomer.
(2) Stoichiometric material consumption equation:
n [C<INF>4</INF>H<INF>6</INF> (butadiene) + Cl<INF>2</INF> (chlorine) +
NaOH (sodium hydroxide)] [rarr]
(C<INF>4</INF>H<INF>5</INF>Cl)<INF>n</INF> (chloroprene rubber) + n
NaCl + n H<INF>2</INF>O
(3) Reasons for the determination: The chloroprene rubber petition
was filed on February 7, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 14691) on April 3, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals butadiene, chlorine, and sodium hydroxide
constitute more than 20 percent by weight of the materials used in the
production of chloroprene rubber, based on the predominant method of
production. Therefore, the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of chloroprene rubber 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: $10.51 per ton. The
conversion factors for the taxable chemicals used in the production of
chloroprene rubber are 0.61 for butadiene, 0.80 for chlorine, and 0.45
for sodium hydroxide. The tax rate is calculated by adding the products
of the conversion factor for each taxable chemical by the tax rate for
that taxable chemical: ((0.61 x $9.74) + (0.80 x $5.40) + (0.45 x
$0.56) = $10.51).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 4002.49.0000.
(ii) Schedule B number: 4002.49.0000.
(iii) CAS number: 9010-98-4.
(2) The Secretary is unable to confirm the following proposed
classification numbers:
(i) HTSUS number: 4002.99.0000.
(ii) Schedule B number: 4002.99.0000.
4. Determination To Add Ethylene-propylene-ethylidene Norbornene Rubber
((C2H4)m-(C3H6)n(C9H12)o; m=56.82, n=40.46, o=2.71) to the List
Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters
of ethylene-propylene-ethylidene norbornene rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>(C<INF>9</INF>H<INF>12</INF>)<INF>o</INF>
; m=56.82, n=40.46, o=2.71), submitted a petition in accordance with
Rev. Proc. 2022-26 requesting to add ethylene-propylene-ethylidene
norbornene rubber ((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>(C<INF>9</INF>H<INF>12</INF>)<INF>o</INF>
; m=56.82, n=40.46, o=2.71) to the List. According to the petition, the
taxable chemicals ethylene, propylene, and butadiene constitute 95.05
percent by weight of the materials used to produce ethylene-propylene-
ethylidene norbornene rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m-</INF>(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>
(C<INF>9</INF>H<INF>12</INF>)<INF>o</INF>; m=56.82, n=40.46, o=2.71),
based on the predominant method of production.
(a) Determination. Ethylene-propylene-ethylidene norbornene rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>(C<INF>9</INF>H<INF>12</INF>)<INF>o</INF>
; m=56.82, n=40.46, o=2.71) is added to the list of taxable substances
under section 4672(a). Other pertinent information is as follows:
[[Page 44885]]
(1) Predominant method of production: The predominant method of
producing ethylene-propylene-ethylidene norbornene rubber is through
the catalytic polymerization of ethylene, propylene, and nonconjugated
diene monomers in a solution using various catalysts. Non-conjugated
diene monomers include ethylidene norbornene and dicyclopentadiene. The
nonconjugated diene monomers are produced from cyclopentadiene and
butadiene, and cyclopentadiene, respectively.
(2) Stoichiometric material consumption equation:
m C<INF>2</INF>H<INF>4</INF> (ethylene) + n C<INF>3</INF>H<INF>6</INF>
(propylene) + o [C<INF>5</INF>H<INF>6</INF> (cyclopentadiene) +
C<INF>4</INF>H<INF>6</INF> (butadiene)] [rarr]
(C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>(C<INF>9</INF>H<INF>12</INF>)<INF>o</INF>
(ethylene-propylene-ethylidene norbornene rubber)
(3) Reasons for the determination: The ethylene-propylene-
ethylidene norbornene rubber ((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>(C<INF>9</INF>H<INF>12</INF>)<INF>o</INF>
; m=56.82, n=40.46, o=2.71) petition was filed on February 7, 2025. The
notice of filing summarizing the petition and requesting comments was
published in the Federal Register (90 FR 14695) on April 3, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals ethylene, propylene, and butadiene constitute
more than 20 percent by weight of the materials used in the production
of ethylene-propylene-ethylidene norbornene rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>(C<INF>9</INF>H<INF>12</INF>)<INF>o</INF>
; m=56.82, n=40.46, o=2.71), based on the predominant method of
production. Therefore, the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of ethylene-propylene-ethylidene
norbornene rubber ((C2H4)m-(C3H6)n(C9H12)o; m=56.82, n=40.46, o=2.71)
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 Secretary: $9.25 per ton. The
conversion factors for the taxable chemicals used in the production of
ethylene-propylene-ethylidene norbornene rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>(C<INF>9</INF>H<INF>12</INF>)<INF>o</INF>
; m=56.82, n=40.46, o=2.71) are 0.44 for ethylene, 0.47 for propylene,
and 0.04 for butadiene. The tax rate is calculated by adding the
products of the conversion factor for each taxable chemical by the tax
rate for that taxable chemical: ((0.44 x $9.74) + (0.47 x $9.74) +
(0.04 x $9.74) = $9.25).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 4002.70.0000.
(ii) Schedule B number: 4002.70.0000.
(iii) CAS number: 25038-36-2.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
5. Determination To Add Ethylene Vinyl Acetate (VA < 50%) ((C2H4)n-
(C4H6O2)m; n=78.95, m=21.05) to the List
Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters
of ethylene vinyl acetate (VA < 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=78.95,
m=21.05), submitted a petition in accordance with Rev. Proc. 2022-26
requesting to add ethylene vinyl acetate (VA < 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=78.95,
m=21.05) to the List. According to the petition, the taxable chemicals
ethylene and methane constitute 66.23 percent by weight of the
materials used to produce ethylene vinyl acetate (VA < 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=78.95,
m=21.05), based on the predominant method of production.
(a) Determination. Ethylene vinyl acetate (VA < 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=78.95,
m=21.05) 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
producing ethylene vinyl acetate (VA < 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=78.95,
m=21.05) is through a solution polymerization employing the monomers of
ethylene and vinyl acetate in tert-butanol as a solvent and a radical
polymerization initiator.
(2) Stoichiometric material consumption equation:
n C<INF>2</INF>H<INF>4</INF> (ethylene) + m [C<INF>2</INF>H<INF>4</INF>
(ethylene) + 1/2 CH<INF>4</INF> (methane) + 2 CO + 1/2 O<INF>2</INF>]
[rarr]
(C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>
)<INF>m</INF> (ethylene vinyl acetate (VA < 50%)) + 1/2m CO<INF>2</INF>
(3) Reasons for the determination: The ethylene vinyl acetate (VA <
50%) ((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=78.95,
m=21.05) petition was filed on February 7, 2025. The notice of filing
summarizing the petition and requesting comments was published in the
Federal Register (90 FR 14688) on April 3, 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 determination. A review of the stoichiometric 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, based on
the predominant method of production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of ethylene vinyl acetate (VA <
50%) ((C2H4)n-(C4H6O2)m; n=78.95, m=21.05) 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: $7.09 per ton. The
conversion factors for the taxable chemicals used in the production of
ethylene vinyl acetate ((VA < 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=78.95,
m=21.05) are 0.70 for ethylene and 0.04 for methane. The tax rate is
calculated by adding the products of the conversion factor for each
taxable chemical by the tax rate for that taxable chemical: ((0.70 x
$9.74) + (0.04 x $6.88) = $7.09).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 3901.30.6000.
(ii) Schedule B number: 3901.30.6000.
(iii) CAS number: 24937-78-8.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
6. Determination To Add Ethylene Vinyl Acetate (VA >= 50%) ((C2H4)n-
(C4H6O2)m; n=75.42, m=24.58) to the List
Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters
of ethylene vinyl acetate (VA >= 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=75.42,
m=24.58), submitted a petition in accordance with Rev. Proc. 2022-26
requesting to add ethylene vinyl acetate (VA >= 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=75.42,
m=24.58) to the List. According to the petition,
[[Page 44886]]
the taxable chemicals ethylene and methane constitute 62.91 percent by
weight of the materials used to produce ethylene vinyl acetate (VA >=
50%) ((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=75.42,
m=24.58), based on the predominant method of production.
(a) Determination. Ethylene vinyl acetate (VA >= 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=75.42,
m=24.58) 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
producing ethylene vinyl acetate (VA >= 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=75.42,
m=24.58) is through a solution polymerization employing the monomers of
ethylene and vinyl acetate in tert-butanol as a solvent and a radical
polymerization initiator.
(2) Stoichiometric material consumption equation:
n C<INF>2</INF>H<INF>4</INF> (ethylene) + m [C<INF>2</INF>H<INF>4</INF>
(ethylene) + 1/2 CH<INF>4</INF> (methane) + 2 CO + 1/2 O<INF>2</INF>]
[rarr]
(C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>
)<INF>m</INF> (ethylene vinyl acetate (VA >= 50%)) + 1/2m
CO<INF>2</INF>
(3) Reasons for the determination: The ethylene vinyl acetate (VA
>= 50%) ((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=75.42,
m=24.58) petition was filed on February 7, 2025. The notice of filing
summarizing the petition and requesting comments was published in the
Federal Register (90 FR 14683) on April 3, 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 determination. A review of the stoichiometric 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, based on
the predominant method of production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of ethylene vinyl acetate (VA
<ls-thn-eq>= 50%) ((C2H4)n-(C4H6O2)m; n=75.42, m=24.58) 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: $6.77 per ton. The
conversion factors for the taxable chemicals used in the production of
ethylene vinyl acetate (VA >= 50%)
((C<INF>2</INF>H<INF>4</INF>)<INF>n</INF>-
(C<INF>4</INF>H<INF>6</INF>O<INF>2</INF>)<INF>m</INF>; n=75.42,
m=24.58) are 0.66 for ethylene and 0.05 for methane. The tax rate is
calculated by adding the products of the conversion factor for each
taxable chemical by the tax rate for that taxable chemical: ((0.66 x
$9.74) + (0.05 x $6.88) = $6.77).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 3905.29.0000.
(ii) Schedule B number: 3905.29.0000.
(iii) CAS number: 24937-78-8.
(2) The Secretary is unable to confirm the following classification
numbers: Not applicable.
7. Determination To Add Hydrogenated Acrylonitrile-Butadiene Rubber
((C4H8)n-(C3H3N)m; n=22.28, m=38.86) to the List
Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters
of hydrogenated acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=22.28, m=38.86), submitted
a petition in accordance with Rev. Proc. 2022-26 requesting to add
hydrogenated acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=22.28, m=38.86) to the
List. According to the petition, the taxable chemicals butadiene,
propylene, ammonia, and methane constitute 63.48 percent by weight of
the materials used to produce hydrogenated acrylonitrile-butadiene
rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=22.28, m=38.86), based on
the predominant method of production.
(a) Determination. Hydrogenated acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=22.28, m=38.86) 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
producing hydrogenated acrylonitrile-butadiene rubber is via catalytic
hydrogenation of acrylonitrile-butadiene rubber which is derived from
the emulsion polymerization of butadiene and acrylonitrile.
(2) Stoichiometric material consumption equation:
n C<INF>4</INF>H<INF>6</INF> (butadiene) + m
[C<INF>3</INF>H<INF>6</INF> (propylene) + NH<INF>3</INF> (ammonia) + 3/
2 O<INF>2</INF>] + n [1/4 CH<INF>4</INF> (methane) + 1/2
H<INF>2</INF>O] [rarr] (C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF> (hydrogenated acrylonitrile-
butadiene rubber) + 3m H<INF>2</INF>O + 1/4n CO<INF>2</INF>
(3) Reasons for the determination: The hydrogenated acrylonitrile-
butadiene rubber (C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=22.28, m=38.86) petition
was filed on February 7, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 14686) on April 3, 2025. The Treasury Department and the IRS
received two non-substantive written comments in response to the notice
of filing. One comment received by the IRS recommended prohibiting the
manufacture of this substance. The other comment received by the IRS
was unrelated to the determination for this substance. The comments did
not address whether hydrogenated acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m;</INF> n=22.28, m=38.86) meets the
weight or value test under section 4672(a)(2)(B). 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 stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals butadiene, propylene, ammonia, and methane
constitute more than 20 percent by weight of the materials used in the
production of, based on the predominant method of production.
Therefore, the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of hydrogenated acrylonitrile-
butadiene rubber (C4H8)n-(C3H3N)m; n=22.28, m=38.86) 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: $9.54 per ton. The
conversion factors for the taxable chemicals used in the production of
hydrogenated acrylonitrile-butadiene rubber
(C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>m</INF>; n=22.28, m=38.86) are 0.36
for butadiene, 0.49 for propylene, 0.20 for ammonia, and 0.03 for
methane. The tax rate is calculated by adding the products of the
conversion factor for each taxable chemical by the tax rate for that
taxable chemical: ((0.36 x $9.74) + (0.49 x $9.74) + (0.20 x $5.28) +
(0.03 x $6.88) = $9.54).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 4002.59.0000.
(ii) Schedule B number: 4002.59.0000.
(iii) CAS number: 308068-83-9.
[[Page 44887]]
(2) The Secretary is unable to confirm the following classification
numbers: Not applicable.
8. Determination To Add Isobutene-isoprene Rubber ((C4H8)n-(C5H8)m;
n=99.10, m=0.90) to the List
Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters
of isobutene-isoprene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>8</INF>)<INF>m</INF>; n=99.10, m=0.90) submitted a
petition in accordance with Rev. Proc. 2022-26 requesting to add
isobutene-isoprene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>8</INF>)<INF>m</INF>; n=99.10, m=0.90) to the List.
According to the petition, the taxable chemical butylene constitutes
98.91 percent by weight of the materials used to produce isobutene-
isoprene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>8</INF>)<INF>m</INF>; n=99.10, m=0.90), based on
the predominant method of production.
(a) Determination. Isobutene-isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>8</INF>)<INF>m</INF>; n=99.10, m=0.90) 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
producing isobutene-isoprene rubber is via the cationic
copolymerization of butylene with isoprene in the presence of a
Friedel-Crafts catalyst at low temperature, around -100[deg]C. The
final product contains 0.7 wt% of additives.
(2) Stoichiometric material consumption equation:
n C<INF>4</INF>H<INF>8</INF> (butylene) + m C<INF>5</INF>H<INF>8</INF>
(isoprene) [rarr]
(C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>m</INF>
(isobutene-isoprene rubber)
(3) Reasons for the determination: The isobutene-isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>8</INF>)<INF>m</INF>; n=99.10, m=0.90) petition was
filed on February 7, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 14689) on April 3, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemical butylene constitutes more than 20 percent by
weight of the materials used in the production of isobutene-isoprene
rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>8</INF>)<INF>m</INF>; n=99.10, m=0.90), based on
the predominant method of production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of isobutene-isoprene rubber
((C4H8)n-(C5H8)m; n=99.10, m=0.90) 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: $9.64 per ton. The
conversion factor for the butylene used in the production of isobutene-
isoprene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>-
(C<INF>5</INF>H<INF>8</INF>)<INF>m</INF>; n=99.10, m=0.90) is 0.99. The
tax rate is calculated by multiplying the conversion factor by the tax
rate for butylene: (0.99 x $9.74 = $9.64).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 4002.31.0000.
(ii) Schedule B number: 4002.31.0000.
(iii) CAS number: 9010-85-9.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
9. Determination To Add Poly(ethylene-propylene) Rubber ((C2H4)m-
(C3H6)n; m=59.04, n=40.96) to the List
Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters
of poly(ethylene-propylene) rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>; m=59.04, n=40.96), submitted
a petition in accordance with Rev. Proc. 2022-26 requesting to add
poly(ethylene-propylene) rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>; m=59.04, n=40.96) to the
List. According to the petition, the taxable chemicals ethylene and
propylene constitute 100 percent by weight of the materials used to
produce poly(ethylene-propylene) rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>; m=59.04, n=40.96), based on
the predominant method of production.
(a) Determination. Poly(ethylene-propylene) rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>; m=59.04, n=40.96) 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
producing poly(ethylene-propylene) rubber is through the catalytic
polymerization of ethylene and propylene monomers in a solution using
various catalysts.
(2) Stoichiometric material consumption equation:
m C<INF>2</INF>H<INF>4</INF> (ethylene) + n C<INF>3</INF>H<INF>6</INF>
(propylene) [rarr] (C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF> (poly(ethylene-propylene)
rubber)
(3) Reasons for the determination: The poly(ethylene-propylene)
rubber ((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>; m=59.04, n=40.96) petition
was filed on February 7, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 14690) on April 3, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals ethylene and propylene constitute more than 20
percent by weight of the materials used in the production of
poly(ethylene-propylene) rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>; m=59.04, n=40.96), based on
the predominant method of production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of poly(ethylene-propylene) rubber
((C2H4)<INF>m</INF>-(C3H6)<INF>n</INF>; m=59.04, n=40.96) 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: $9.74 per ton. The
conversion factors for the taxable chemicals used in the production of
poly(ethylene-propylene) rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>m</INF>-
(C<INF>3</INF>H<INF>6</INF>)<INF>n</INF>; m=59.04, n=40.96) are 0.49
for ethylene and 0.51 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: ((0.49 x $9.74) + (0.51 x
$9.74) = $9.74).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification number: CAS number: 9010-71-1.
(2) The Secretary is unable to confirm the following proposed
classification numbers:
(i) HTSUS number: 3901.40.0000.
(ii) Schedule B number: 3901.40.0000.
10. Determination To Add Emulsion Styrene-Butadiene Rubber ((C4H6)m-
(C8H8)n; m=15.83, n=2.53) to the List
Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters
of emulsion styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=15.83; n=2.53), submitted a
petition in accordance with Rev. Proc. 2022-26 requesting to add
[[Page 44888]]
emulsion styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=15.83; n=2.53) to the List.
According to the petition, the taxable chemicals butadiene, benzene,
and ethylene constitute 100 percent by weight of the materials used to
produce emulsion styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=15.83; n=2.53), based on
the predominant method of production.
(a) Determination. Emulsion styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=15.83; n=2.53) 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
producing emulsion styrene-butadiene rubber is through the emulsion
polymerization of butadiene and styrene initiated by free radicals.
Styrene monomer is produced by the dehydrogenation of ethylbenzene.
Ethylbenzene is produced via a Friedel-Crafts reaction of benzene and
ethylene.
(2) Stoichiometric material consumption equation:
m C<INF>4</INF>H<INF>6</INF> (butadiene) + n
[C<INF>6</INF>H<INF>6</INF> (benzene) + C<INF>2</INF>H<INF>4</INF>
(ethylene)] [rarr] (C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF> (emulsion styrene-butadiene
rubber) + n H<INF>2</INF> (hydrogen)
(3) Reasons for the determination: The emulsion styrene-butadiene
rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=15.83; n=2.53) petition was
filed on February 7, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 14686) on April 3, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals butadiene, benzene, and ethylene constitute more
than 20 percent by weight of the materials used in the production of
emulsion styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=15.83; n=2.53), based on
the predominant method of production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of emulsion styrene-butadiene
rubber ((C4H6)<INF>m</INF>-(C8H8)<INF>n</INF>; m=15.83; n=2.53) 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: $9.74 per ton. The
conversion factors for the taxable chemicals used in the production of
emulsion styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=15.83; n=2.53) are 0.76 for
butadiene, 0.18 for benzene, and 0.06 for ethylene. 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: ((0.76 x
$9.74) + (0.18 x $9.74) + (0.06 x $9.74) = $9.74).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS numbers: 4002.19.0015 (rubber), 4002.11.0000 (latex).
(ii) Schedule B numbers: 4002.19.9000 (rubber), 4002.11.0000
(latex).
(iii) CAS number: 9003-55-8.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
11. Determination To Add Solution Styrene-butadiene Rubber ((C4H6)m-
(C8H8)n; m=67.16, n=32.85) to the List
Arlanxeo USA LLC and Arlanxeo Canada Inc., importers and exporters
of solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=67.16; n=32.85), submitted
a petition in accordance with Rev. Proc. 2022-26 requesting to add
solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=67.16; n=32.85) to the
List. According to the petition, the taxable chemicals butadiene,
benzene, and ethylene constitute 100 percent by weight of the materials
used to produce solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=67.16; n=32.85), based on
the predominant method of production.
(a) Determination. Solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=67.16; n=32.85) 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
producing solution styrene-butadiene rubber is through the anionic
polymerization of butadiene and styrene initiated by alkyl lithium
compounds in hexanes as solvent. Styrene monomer is produced by the
dehydrogenation of ethylbenzene. Ethylbenzene is produced via a
Friedel-Crafts reaction of benzene and ethylene.
(2) Stoichiometric material consumption equation:
m C<INF>4</INF>H<INF>6</INF> (butadiene) + n
[C<INF>6</INF>H<INF>6</INF> (benzene) + C<INF>2</INF>H<INF>4</INF>
(ethylene)] [rarr] (C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF> (solution styrene-butadiene
rubber) + n H<INF>2</INF> (hydrogen); m=67.16; n=32.85
(3) Reasons for the determination: The solution styrene-butadiene
rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=67.16; n=32.85) petition
was filed on February 7, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 14690) on April 3, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals butadiene, benzene, and ethylene constitute more
than 20 percent by weight of the materials used in the production of
solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=67.16; n=32.85), based on
the predominant method of production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of solution styrene-butadiene
rubber ((C4H6)<INF>m</INF>-(C8H8)<INF>n</INF>; m=67.16; n=32.85) 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: $9.74 per ton. The
conversion factors for the taxable chemicals used in the production of
solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=67.16; n=32.85) are 0.51
for butadiene, 0.36 for benzene, and 0.13 for ethylene. 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) + (0.36 x $9.74) + (0.13 x $9.74) = $9.74).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification number: CAS number: 9003-55-8.
(2) The Secretary is unable to confirm the following proposed
classification numbers:
[[Page 44889]]
(i) HTSUS number: 4002.19.0016.
(ii) Schedule B number: 4002.19.1600.
12. Determination To Add Emulsion Styrene Butadiene Rubber ((C4H6)m-
(C8H8)n; m=14.14, n=2.26) to the List
Michelin North America, Inc., an importer of emulsion styrene
butadiene rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=14.14, n=2.26), submitted a
petition in accordance with Rev. Proc. 2022-26 requesting to add
emulsion styrene butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=14.14, n=2.26) to the List.
According to the petition, the taxable chemicals butadiene, benzene,
and ethylene constitute 100 percent by weight of the materials used to
produce emulsion styrene butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=14.14, n=2.26), based on
the predominant method of production.
(a) Determination. Emulsion styrene butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=14.14, n=2.26) 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
producing emulsion styrene butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=14.14, n=2.26) is through a
low temperature, emulsion copolymerization of butadiene and styrene,
using fatty and rosin acid soaps as an emulsifier, and organic
hydroperoxides as an initiator. Styrene monomer is produced by the
dehydrogenation of ethylbenzene. Ethylbenzene is produced via a
Friedel-Crafts reaction of benzene and ethylene.
(2) Stoichiometric material consumption equation:
m C<INF>4</INF>H<INF>6</INF> (butadiene) + n
[C<INF>6</INF>H<INF>6</INF> (benzene) + C<INF>2</INF>H<INF>4</INF>
(ethylene)] [rarr] (C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF> (emulsion styrene butadiene
rubber) + n H<INF>2</INF> (hydrogen); m=14.14; n=2.26
(3) Reasons for the determination: The emulsion styrene butadiene
rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=14.14, n=2.26) petition was
filed on February 7, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 14692) on April 3, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals butadiene, benzene, and ethylene constitute more
than 20 percent by weight of the materials used in the production of
emulsion styrene butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=14.14, n=2.26), based on
the predominant method of production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of emulsion styrene butadiene
rubber ((C4H6)<INF>m</INF>-(C8H8)<INF>n</INF>; m=14.14, n=2.26) 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: $9.74 per ton. The
conversion factors for the taxable chemicals used in the production of
emulsion styrene butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=14.14, n=2.26) are 0.76 for
butadiene, 0.18 for benzene, and 0.06 for ethylene. 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: ((0.76 x
$9.74) + (0.18 x $9.74) + (0.06 x $9.74) = $9.74).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 4002.19.0015.
(ii) Schedule B number: 4002.19.9000.
(iii) CAS number: 9003-55-8.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
13. Determination To Add Solution Styrene-butadiene Rubber ((C4H6)m-
(C8H8)n; m=13.31, n=2.50) to the List
Michelin North America, Inc., an importer of solution styrene-
butadiene rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=13.31, n=2.50), submitted a
petition in accordance with Rev. Proc. 2022-26 requesting to add
solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=13.31, n=2.50) to the List.
According to the petition, the taxable chemicals butadiene, benzene and
ethylene constitute 100 percent by weight of the materials used to
produce solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=13.31, n=2.50), based on
the predominant method of production.
(a) Determination. Solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=13.31, n=2.50) 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
producing solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=13.31, n=2.50) is through
the continuous polymerization of butadiene and styrene initiated by
alkyl lithium compounds in toluene or CMHC (cyclohexane and
methylhexane) as solvents. Styrene monomer is produced by the
dehydrogenation of ethylbenzene. Ethylbenzene is produced via a
Friedel-Crafts reaction of benzene and ethylene.
(2) Stoichiometric material consumption equation:
m C<INF>4</INF>H<INF>6</INF> (butadiene) + n
[C<INF>6</INF>H<INF>6</INF> (benzene) + C<INF>2</INF>H<INF>4</INF>
(ethylene)] [rarr] (C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF> (solution styrene butadiene
rubber) + n H<INF>2</INF> (hydrogen); m=13.31; n=2.5
(3) Reasons for the determination: The solution styrene-butadiene
rubber ((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=13.31, n=2.50) petition was
filed on February 7, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 14693) on April 3, 2025. The Treasury Department and the IRS
received one non-substantive written comment on the necessity of the
filing to understand its impact in response to the notice of filing.
The comment did not address whether solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=13.31, n=2.50) meets the
weight or value test under section 4672(a)(2)(B). 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 stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals butadiene, benzene and ethylene constitute more
than 20 percent by weight of the materials used in the production of
solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=13.31, n=2.50), based on
the predominant method of production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of solution styrene-butadiene
rubber ((C4H6)<INF>m</INF>-(C8H8)<INF>n</INF>; m=13.31, n=2.50) 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.
[[Page 44890]]
(6) Tax rate prescribed by the Secretary: $9.74 per ton. The
conversion factors for the taxable chemicals used in the production of
solution styrene-butadiene rubber
((C<INF>4</INF>H<INF>6</INF>)<INF>m</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>n</INF>; m=13.31, n=2.50) are 0.73 for
butylene, 0.20 for benzene, and 0.07 for ethylene. 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: ((0.73 x
$9.74) + (0.20 x $9.74) + (0.07 x $9.74) = $9.74).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 4002.19.0016.
(ii) Schedule B number: 4002.19.1600.
(iii) CAS number: 9003-55-8.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
14. Determination To Add Hydrogenated Acrylonitrile-butadiene Rubber
((C4H8)x-(C3H3N)y-(C15H24O)a; x=2,783.05, y=1,907.27, a=5.74) to the
List
Zeon Chemicals L.P., an importer and exporter of hydrogenated
acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>y</INF>-
(C<INF>15</INF>H<INF>24</INF>O)<INF>a</INF>; x=2,783.05, y=1,907.27,
a=5.74), also known as ``HNBR,'' submitted a petition in accordance
with Rev. Proc. 2022-26 requesting to add HNBR to the List. According
to the petition, the taxable chemicals butadiene, propylene, ammonia,
methane, butylene, toluene, sulfuric acid, and sodium hydroxide
constitute 67.01 percent by weight of the materials used to produce
HNBR, based on the predominant method of production.
(a) Determination. Hydrogenated acrylonitrile-butadiene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>y</INF>-
(C<INF>15</INF>H<INF>24</INF>O)<INF>a</INF>; x=2,783.05, y=1,907.27,
a=5.74) 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
producing HNBR is via catalytic hydrogenation of acrylonitrile-
butadiene rubber (``NBR'') in a solution of acetone and in the presence
of a catalyst. NBR is derived from the emulsion polymerization of
butadiene and acrylonitrile. Acrylonitrile monomer is produced by the
SOHIO process (i.e., catalytic ammoxidation of propylene). Hydrogen is
made from steam-methane reforming. Butylated hydroxytoluene is produced
from the reaction of p-cresol with butylene. p-Cresol is prepared by a
two-step route beginning with the sulfonation of toluene, followed by
basic hydrolysis.
(2) Stoichiometric material consumption equation:
x C<INF>4</INF>H<INF>6</INF> (butadiene) + y C<INF>3</INF>H<INF>6</INF>
(propylene) + y NH<INF>3</INF> (ammonia) + 3/2y O<INF>2</INF> + 1/2x
CH<INF>4</INF> (methane) + x H<INF>2</INF>O + a
C<INF>7</INF>H<INF>8</INF> (toluene) + a H<INF>2</INF>SO<INF>4</INF>
(sulfuric acid) + 2a NaOH (sodium hydroxide) + 2a
C<INF>4</INF>H<INF>8</INF> (butylene) [rarr]
(C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>-
(C<INF>3</INF>H<INF>3</INF>N)<INF>y</INF>-
(C<INF>15</INF>H<INF>24</INF>O)<INF>a</INF> (HNBR) + 1/2x
CO<INF>2</INF> (carbon dioxide)+ (3y+2a) H<INF>2</INF>O (water) + a
Na<INF>2</INF>SO<INF>3</INF> (sodium sulfite)+ x H<INF>2</INF> \1\
(hydrogen)
---------------------------------------------------------------------------
\1\ The petition, and consequently the notice of filing,
inadvertently omitted ``x H<INF>2</INF>'' from the products side of
the stoichiometric material consumption equation. This omission has
no impact on the weight or value test. For clarity ``x
H<INF>2</INF>'' has been included here.
(3) Reasons for the determination: The HNBR petition was filed on
February 14, 2025. The notice of filing summarizing the petition and
requesting comments was published in the Federal Register (90 FR 14685)
on April 3, 2025, and a correction was published in the Federal
Register (90 FR 19245) on May 6, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals butadiene, propylene, ammonia, methane, butylene,
toluene, sulfuric acid, and sodium hydroxide constitute more than 20
percent by weight of the materials used in the production of HNBR,
based on the predominant method of production. Therefore, the test in
section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of HNBR 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 Secretary: $10.02 per ton. The
conversion factors for the taxable chemicals used in the production of
HNBR are 0.58 for butadiene, 0.31 for propylene, 0.13 for ammonia, 0.09
for methane, 0.002 for butylene, 0.002 for toluene, 0.002 for sulfuric
acid, and 0.002 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: ((0.58 x $9.74) + (0.31 x
$9.74) + (0.13 x $5.28) + (0.09 x $6.88) + (0.002 x $9.74) + (0.002 x
$9.74) + (0.002 x $0.52) + (0.002 x $0.56) = $10.02).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 4002.59.0000.\2\
---------------------------------------------------------------------------
\2\ The Notice of Filing erroneously stated that the HTSUS
number as ``4002.59.000'' and the Schedule B number as
``4002.59.000.'' These errors are corrected here.
---------------------------------------------------------------------------
(ii) Schedule B number: 4002.59.0000.
(iii) CAS number: 88254-10-8.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
15. Determination To Add Bromobutyl Isobutylene Isoprene Rubber
(((C4H8)x(C5H8)y(Br2)z); x=7071, y=59, z=50) to the List
Exxon Mobil Corporation, an exporter of bromobutyl isobutylene
isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
(Br<INF>2</INF>)<INF>z</INF>; x=7071, y=59, z=50), also known as
``BIIR,'' submitted a petition in accordance with Rev. Proc. 2022-26
requesting to add BIIR to the List. According to the petition, the
taxable chemicals isobutylene (an isomer of butylene) and bromine
constitute 99.01 percent by weight of the materials used to produce
BIIR, based on the predominant method of production.
(a) Determination. Bromobutyl isobutylene isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
(Br<INF>2</INF>)<INF>z</INF>; x=7071, y=59, z=50) 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
regular butyl rubber production is using a carbocationic polymerization
reaction of isobutylene and a comonomer of isoprene. The catalyst
system used is typically composed of aluminum chloride, boron
trifluoride or similar dissolved in a methyl chloride solvent. Monomer
feed of isobutylene and isoprene dissolved in a methyl chloride solvent
are fed to a reactor operated at approximately -100 [deg]C to control
the rapid exothermic polymerization reaction generating a high
molecular weight butyl rubber polymer. To obtain this high molecular
weight polymer it is necessary for the feed monomers to be as pure as
possible ensuring that the feed system stays as dry as possible. The
methyl chloride and unreacted monomers are flashed overhead and
recycled back to the feed
[[Page 44891]]
system while the polymer is precipitated out as a solid which is
finished and packaged.
The polymerization process for BIIR starts with the exact same
process for regular butyl rubber outlined above. A subsequent
halogenation step is then carried out in a well agitated vessel to
ionically substitute a bromine molecule to the polymer backbone while
the polymer is dissolved in an appropriate solvent. The solvent is then
flashed precipitating out a solid which is then baled and packaged.
(2) Stoichiometric material consumption equation:
7071 C<INF>4</INF>H<INF>8</INF> (isobutylene) + 59
C<INF>5</INF>H<INF>8</INF> (isoprene) + 50 Br<INF>2</INF> (bromine)
[rarr] [7071 C<INF>4</INF>H<INF>8</INF> + 59 C<INF>5</INF>H<INF>8</INF>
+ 50 Br<INF>2</INF>] (BIIR)
(3) Reasons for the determination: The BIIR petition was filed on
April 8, 2025.\3\ The notice of filing summarizing the petition and
requesting comments was published in the Federal Register (90 FR 20346)
on May 13, 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.
---------------------------------------------------------------------------
\3\ The Notice of Filing erroneously stated the year of filing
as 2023. This error is corrected here.
---------------------------------------------------------------------------
The Secretary followed the process in section 4672(a)(2)(B) in
making this determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals isobutylene (an isomer of butylene) and bromine
constitute more than 20 percent by weight of the materials used in the
production of BIIR, based on the predominant method of production.
Therefore, the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of BIIR 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: $9.63 per ton. The
conversion factors for the taxable chemicals used in the production of
BIIR are 0.97 for butylene and 0.02 for bromine. 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: ((0.97 x
$9.74) + (0.02 x $8.90) = $9.63).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 4002.39.00.
(ii) Schedule B number: 4002.39.00.
(iii) CAS number: 68441-14-5.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
16. Determination To Add Chlorobutyl Isobutylene Isoprene Rubber
((C4H8)x(C5H8)y(Cl2)z); x=7036, y=88, z=70) to the List
Exxon Mobil Corporation, an exporter of chlorobutyl isobutylene
isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
(Cl<INF>2</INF>)<INF>z</INF>); x=7036, y=88, z=70), also known as
``CIIR,'' submitted a petition in accordance with Rev. Proc. 2022-26
requesting to add CIIR to the List. According to the petition, the
taxable chemicals isobutylene (an isomer of butylene) and chlorine
constitute 98.50 percent by weight of the materials used to produce
CIIR, based on the predominant method of production.
(a) Determination. Chlorobutyl isobutylene isoprene rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
(Cl<INF>2</INF>)<INF>z</INF>); x=7036, y=88, z=70) 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 regular butyl rubber is using a carbocationic
polymerization reaction of isobutylene and a comonomer of isoprene. The
catalyst system used is typically composed of aluminum chloride, boron
trifluoride or similar with an initiator dissolved in a methyl chloride
solvent. Monomer feed of isobutylene and isoprene dissolved in a methyl
chloride solvent are fed to a reactor operated at approximately -100
[deg]C to control the rapid exothermic polymerization reaction
generating a high molecular weight regular butyl rubber polymer. To
obtain this high molecular weight polymer it is necessary for the feed
monomers to be as pure as possible as well as ensuring that the feed
system stays as dry as possible. The methyl chloride and unreacted
monomers are flashed overhead and recycled back to the feed system
while the polymer is precipitated out as a solid which is then baled
and packaged.
The polymerization process for CIIR starts with the exact same
process for regular butyl rubber outlined above. A subsequent
halogenation step is then carried out in a well agitated vessel to
ionically substitute a chlorine molecule to the polymer backbone while
the polymer is dissolved in an appropriate solvent. The solvent is then
flashed, precipitating out a solid which is then baled and packaged.
(2) Stoichiometric material consumption equation:
7036 C<INF>4</INF>H<INF>8</INF> (isobutylene) + 88
C<INF>5</INF>H<INF>8</INF> (isoprene) + 70 Cl<INF>2</INF> (chlorine)
[rarr] [7036 C<INF>4</INF>H<INF>8</INF> + 88
C<INF>5</INF>H<INF>8 +</INF> 70 Cl<INF>2</INF>] (CIIR)
(3) Reasons for the determination: The CIIR petition was filed on
April 8, 2025. The notice of filing summarizing the petition and
requesting comments was published in the Federal Register (90 FR 20350)
on May 13, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals isobutylene (an isomer of butylene) and chlorine
constitute more than 20 percent by weight of the materials used in the
production of CIIR, based on the predominant method of production.
Therefore, the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of CIIR 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: $9.50 per ton. The
conversion factors for the taxable chemicals used in the production of
CIIR are 0.97 for butylene and 0.01 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: ((0.97 x
$9.74) + (0.01 x $5.40) = $9.50).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 4002.39.00.
(ii) Schedule B number: 4002.39.00.
(iii) CAS number: 68081-82-3.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
17. Determination To Add DIPE-Di-isopropyl Ether to the List
Exxon Mobil Corporation, an exporter of DIPE-di-isopropyl ether
submitted a
[[Page 44892]]
petition in accordance with Rev. Proc. 2022-26 requesting to add DIPE-
di-isopropyl ether to the List. According to the petition, the taxable
chemical propylene constitutes 82.40 percent by weight of the materials
used to produce DIPE-di-isopropyl ether, based on the predominant
method of production.
(a) Determination. DIPE-di-isopropyl ether is added to the list of
taxable substances under section 4672(a). Other pertinent information
is as follows:
(1) Predominant method of production: DIPE-di-isopropyl ether is
produced via isopropyl alcohol (IPA) production using a two-step
indirect hydration process. A mixed propane/propylene stream is reacted
with aqueous sulfuric acid to form a H<INF>2</INF>SO<INF>4</INF>/
propylene extract. The formed isopropyl hydrogen sulfate is further
reacted with additional IPA under acidic conditions to form DIPE-di-
isopropyl ether such that two moles of isopropanol are converted to one
mole of DIPE-di-isopropyl ether and one mole of water.
(2) Stoichiometric material consumption equation:
2 C<INF>3</INF>H<INF>6</INF> [propylene] + H<INF>2</INF>O [water]
[rarr] C<INF>6</INF>H<INF>14</INF>O [DIPE-di-isopropyl ether]
(3) Reasons for the determination: The DIPE-di-isopropyl ether
petition was filed on May 1, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 21126) on May 16, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemical propylene constitutes more than 20 percent by
weight of the materials used in the production of DIPE-di-isopropyl
ether, based on the predominant method of production. Therefore, the
test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of DIPE-di-isopropyl 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 Secretary: $7.99 per ton. The
conversion factor for the propylene used in the production of DIPE-di-
isopropyl ether is 0.82. The tax rate is calculated by multiplying the
conversion factor by the tax rate for propylene: (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: 2909.19.18.00.
(ii) Schedule B number: 2909.19.18.00.
(iii) CAS number: 108-20-3.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
18. Determination To Add Di-isodecyl Phthalate to the List
Exxon Mobil Corporation, an exporter of di-isodecyl phthalate,
submitted a petition in accordance with Rev. Proc. 2022-26 requesting
to add di-isodecyl phthalate to the List. According to the petition,
the taxable chemicals propylene and orthoxylene (an isomer of xylene)
constitute 64.50 percent by weight of the materials used to produce di-
isodecyl phthalate, based on the predominant method of production.
(a) Determination. Di-isodecyl phthalate 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
producing di-isodecyl phthalate is via esterification.
This process can be readily carried out in heated kettles with
agitation and provision for water takeoff. Esterification catalysts
(e.g., sulfuric acid or p-toluenesulfonic acid) speed the reaction and
are neutralized, washed, and then removed. The purity requirements for
commercial plasticizers are very high; phthalate esters are usually
colorless and are mostly odorless. In the case of phthalates, the
esterification is carried out through the reaction of phthalic
anhydride and 2-ethylhexanol to produce dioctyl phthalate (DOP).
This reaction usually requires an excess of alcohol, which is
readily recycled. Analogous syntheses yield aliphatic dicarboxylic acid
esters, benzoates, and trimellitates.
(2) Stoichiometric material consumption equation:
5.45 C<INF>3</INF>H<INF>6</INF> [propylene] + 0.35
C<INF>5</INF>H<INF>10</INF> [amylene] + 2 CO [carbon monoxide] + 4
H<INF>2</INF> [hydrogen] + C<INF>8</INF>H<INF>10</INF> [orthoxylene] +
3 O<INF>2</INF> [oxygen] [rarr]
C<INF>28</INF>H<INF>46</INF>O<INF>4</INF> [di-isodecyl phthalate] + 4
H<INF>2</INF>O [water]
(3) Reasons for the determination: The di-isodecyl phthalate
petition was filed on April 8, 2025. The notice of filing summarizing
the petition and requesting comments was published in the Federal
Register (90 FR 20354) on May 13, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals propylene and orthoxylene (an isomer of xylene)
constitute more than 20 percent by weight of the materials used in the
production of di-isodecyl phthalate, based on the predominant method of
production. Therefore, the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of di-isodecyl phthalate 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: $7.31 per ton. The
conversion factors for the taxable chemicals used in the production of
di-isodecyl phthalate are 0.51 for propylene and 0.24 for xylene. 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) + (0.24 x $9.74) = $7.31).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers: Not applicable.
(2) The Secretary is unable to confirm the following proposed
classification numbers:
(i) HTSUS number: 2917.33.00.10.
(ii) Schedule B number: 2917.33.00.10.
(iii) CAS number: 68515-49-1.
19. Determination To Add Di-isononyl Adipate to the List
Exxon Mobil Corporation, an exporter of di-isononyl adipate, also
known as ``DINA,'' submitted a petition in accordance with Rev. Proc.
2022-26 requesting to add DINA to the List. According to the petition,
the taxable chemicals propylene, benzene, and nitric acid constitute
79.20 percent by weight of the materials used to produce DINA, based on
the predominant method of production.
[[Page 44893]]
(a) Determination. Di-isononyl adipate is added to the list of
taxable substances under section 4672(a). Other pertinent information
is as follows:
(1) Predominant method of production: DINA is produced via
esterification. The di-isononyl adipate di-ester is made by reacting
primary isononyl (C9) alcohol with adipic acid. The ester is produced
by esterification of two moles of isononyl C9 alcohol and one mole of
adipic acid in the presence of a catalyst.
By using excess alcohol (up to 30% molar excess of C9 alcohol) and
removing the water, the equilibrium is shifted towards the formation of
the di-ester. The reactants are charged into a reactor and heated up.
The reaction rate is accelerated by using, for example, tetra-n-butyl
titanate introduced at high temperature (140 [deg]C-250 [deg]C), while
removing the water formed.
Excess alcohol is distilled from the ester by vacuum prior to
neutralization and recycled into subsequent batches. The final ester is
purified by neutralizing with a base such as an aqueous solution of
sodium carbonate. The remaining excess water is distilled off and the
ester is then filtered using filter agents. The degree of purity of the
ester has a minimum 99.0 wt%.
(2) Stoichiometric material consumption equation:
4.82 C<INF>3</INF>H<INF>6</INF> [propylene] + 0.30
C<INF>5</INF>H<INF>10</INF> [amylene] + 2 CO [carbon monoxide] + 7
H<INF>2</INF> [hydrogen] + C<INF>6</INF>H<INF>6</INF> [benzene] + 0.50
O<INF>2</INF> [oxygen] + 2 HNO<INF>3</INF> [nitric acid] [rarr]
C<INF>24</INF>H<INF>46</INF>O<INF>4</INF> [di-isononyl adipate] + 4
H<INF>2</INF>O [water] + N<INF>2</INF>O [nitrous oxide]
(3) Reasons for the determination: The DINA petition was filed on
May 1, 2025. The notice of filing summarizing the petition and
requesting comments was published in the Federal Register (90 FR 21131)
on May 16, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals propylene, benzene, and nitric acid constitute
more than 20 percent by weight of the materials used in the production
of DINA, based on the predominant method of production. Therefore, the
test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of DINA 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: $7.07 per ton. The
conversion factors for the taxable chemicals used in the production of
DINA are 0.51 for propylene, 0.20 for benzene, and 0.32 for nitric
acid. 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) + (0.20 x $9.74) + (0.32 x $0.48) =
$7.07).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 2917.12.20.00.
(ii) Schedule B number: 2917.12.2000.
(iii) CAS number: 33703-08-1.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
20. Determination To Add Di-isononyl Phthalate to the List
Exxon Mobil Corporation, an exporter of di-isononyl phthalate,
submitted a petition in accordance with Rev. Proc. 2022-26 requesting
to add di-isononyl phthalate to the List. According to the petition,
the taxable chemicals propylene and orthoxylene (an isomer of xylene)
constitute 62.90 percent by weight of the materials used to produce di-
isononyl phthalate, based on the predominant method of production.
(a) Determination. Di-isononyl phthalate 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
producing di-isononyl phthalate is via esterification.
Most plasticizers are products of simple esterification reactions,
which can be readily carried out in heated kettles with agitation and
provision for water takeoff. While some plants produce plasticizers by
such batch methods, newer, highly automated plants operate
continuously, particularly if they emphasize a single product.
Esterification catalysts (e.g. sulfuric acid or p-toluenesulfonic acid)
speed the reaction and are neutralized, washed, and then removed. The
purity requirements for commercial plasticizers are very high;
phthalate esters are usually colorless and are mostly odorless. The
reaction usually requires an excess of alcohol, which is readily
recycled. Analogous syntheses yield aliphatic dicarboxylic acid esters,
benzoates, and trimellitates.
The hydrogen used for these reactions is not produced from steam-
methane reforming; the source is from a POx reactor, which feeds
liquids, not methane. The POx process is an industrial process that
converts hydrocarbons feeds into syngas (a combination of H<INF>2</INF>
and CO gas). The hydrocarbon feed is in the liquid state; it does not
feed gas (such as methane) or solids. The unit feeds a variety of
liquid hydrocarbons such as paraffins, olefins, and aromatics in the
C9-C20 range, obtained from the refinery pipestills and other chemicals
units.
(2) Stoichiometric material consumption equation:
5.12 x 0.94 C<INF>3</INF>H<INF>6</INF> [propylene] + 5.12 x 0.06
C<INF>5</INF>H<INF>10</INF> [amylene] + 2 CO [carbon monoxide] + 4
H<INF>2</INF> [hydrogen] + C<INF>8</INF>H<INF>10</INF> [orthoxylene] +
3 O<INF>2</INF> [oxygen] [rarr]
C<INF>26</INF>H<INF>42</INF>O<INF>4</INF> [di-isononyl phthalate] + 4
H<INF>2</INF>O [water]
(3) Reasons for the determination: The di-isononyl phthalate
petition was filed on May 1, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 20551) on May 14, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals propylene and orthoxylene (an isomer of xylene)
constitute more than 20 percent by weight of the materials used in the
production of di-isononyl phthalate, based on the predominant method of
production. Therefore, the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of di-isononyl phthalate 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: $7.11 per ton. The
conversion factors for the taxable chemicals used in the production of
di-isononyl phthalate are 0.48 for propylene and 0.25 for xylene. The
tax rate is calculated by
[[Page 44894]]
adding the products of the conversion factor for each taxable chemical
and the tax rate for that taxable chemical: ((0.48 x $9.74) + (0.25 x
$9.74) = $7.11).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers: Not applicable.
(2) The Secretary is unable to confirm the following proposed
classification numbers:
(i) HTSUS number: 2917.33.00.50.
(ii) Schedule B number: 2917.33.00.50.
(iii) CAS number: 68515-48-0.
21. Determination To Add Di-tridecyl Phthalate to the List
Exxon Mobil Corporation, an exporter of di-tridecyl phthalate,
submitted a petition in accordance with Rev. Proc. 2022-26 requesting
to add di-tridecyl phthalate to the List. According to the petition,
the taxable chemicals propylene and orthoxylene (an isomer of xylene)
constitute 68.10 percent by weight of the materials used to produce di-
tridecyl phthalate, based on the predominant method of production.
(a) Determination. Di-tridecyl phthalate 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
producing di-tridecyl phthalate \4\ is via esterification.
---------------------------------------------------------------------------
\4\ The Notice of Filing for di-tridecyl phthalate had a
typographical error misstating the name of the taxable substance in
the predominant method of production section. This error is
corrected here.
---------------------------------------------------------------------------
This process can be readily carried out in heated kettles with
agitation and provision for water takeoff. Esterification catalysts
(e.g., sulfuric acid or p-toluenesulfonic acid) speed the reaction and
are neutralized, washed, and then removed. The purity requirements for
commercial plasticizers are very high; phthalate esters are usually
colorless and are mostly odorless. In the case of phthalates, the
esterification is carried out through the reaction of phthalic
anhydride and 2-ethylhexanol to produce dioctyl phthalate (DOP).
This reaction usually requires an excess of alcohol, which is
readily recycled. Analogous syntheses yield aliphatic dicarboxylic acid
esters, benzoates, and trimellitates.
(2) Stoichiometric material consumption equation:
7.70 x 0.94 C<INF>3</INF>H<INF>6</INF> [propylene] + 7.70 x 0.06
C<INF>5</INF>H<INF>10</INF> [amylene] + 2 CO [carbon monoxide] + 4
H<INF>2</INF> [hydrogen] + C<INF>8</INF>H<INF>10</INF> [orthoxylene] +
3 O<INF>2</INF> [oxygen] [rarr]
C<INF>34</INF>H<INF>58</INF>O<INF>4</INF> [di-tridecyl phthalate] + 4
H<INF>2</INF>O [water]
(3) Reasons for the determination: The di-tridecyl phthalate
petition was filed on April 8, 2025. The notice of filing summarizing
the petition and requesting comments was published in the Federal
Register (90 FR 20352) on May 13, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals propylene and orthoxylene (an isomer of xylene)
constitute more than 20 percent by weight of the materials used in the
production of di-tridecyl phthalate, based on the predominant method of
production. Therefore, the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of di-tridecyl phthalate 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: $7.50 per ton. The
conversion factors for the taxable chemicals used in the production of
di-tridecyl phthalate are 0.57 for propylene and 0.20 for xylene. 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:
((0.57 x $9.74) + (0.20 x $9.74) = $7.50).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers: Not applicable.
(2) The Secretary is unable to confirm the following proposed
classification numbers:
(i) HTSUS number: 2917.34.01.50.
(ii) Schedule B number: 2917.34.0150.
(iii) CAS number: 68515-47-9.
22. Determination To Add Ethylene Propylene Diene (EPDM) Rubber
((C2H4)x(C3H6)y(C9H12)<INF>z</INF>; x=5134, y=2250, z=98) to the List
Exxon Mobil Corporation, an exporter of ethylene propylene diene
(EPDM) rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>x</INF>(C<INF>3</INF>H<INF>6</INF>)<INF>y</INF>
(C<INF>9</INF>H<INF>12</INF>)<INF>z</INF>; x=5134, y=2250, z=98),
submitted a petition in accordance with Rev. Proc. 2022-26 requesting
to add EPDM rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>x</INF>(C<INF>3</INF>H<INF>6</INF>)<INF>y</INF>
(C<INF>9</INF>H<INF>12</INF>)<INF>z</INF>; x=5134, y=2250, z=98) to the
List. According to the petition, the taxable chemicals ethylene,
propylene, and butadiene constitute 97.41 percent by weight of the
materials used to produce EPDM rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>x</INF>(C<INF>3</INF>H<INF>6</INF>)<INF>y</INF>
(C<INF>9</INF>H<INF>12</INF>)<INF>z</INF>; x=5134, y=2250, z=98), based
on the predominant method of production.
(a) Determination. Ethylene propylene diene (EPDM) rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>x</INF>(C<INF>3</INF>H<INF>6</INF>)<INF>y</INF>
(C<INF>9</INF>H<INF>12</INF>)<INF>z</INF>; x=5134, y=2250, z=98) 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
producing EPDM rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>x</INF>(C<INF>3</INF>H<INF>6</INF>)<INF>y</INF>
(C<INF>9</INF>H<INF>12</INF>)<INF>z</INF>; x=5134, y=2250, z=98) is
copolymerization of ethylene and propylene with or without a small
amount of a non-conjugated diene.
(2) Stoichiometric material consumption equation:
5,134 C<INF>2</INF>H<INF>4</INF> [ethylene] + 2,250
C<INF>3</INF>H<INF>6</INF> [propylene] + 98 C<INF>4</INF>H<INF>6</INF>
[butadiene] + 98 C<INF>5</INF>H<INF>6</INF> [cyclopentadiene] [rarr]
(5,134 C<INF>2</INF>H<INF>4</INF> + 2,250 C<INF>3</INF>H<INF>6</INF> +
98 C<INF>9</INF>H<INF>12</INF>) [EPDM]
(3) Reasons for the determination: The EPDM rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>x</INF>(C<INF>3</INF>H<INF>6</INF>)<INF>y</INF>
(C<INF>9</INF>H<INF>12</INF>)<INF>z</INF>; x=5134, y=2250, z=98)
petition was filed on May 1, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 21825) on May 21, 2025. The Treasury Department and the IRS
received one non-substantive written comment regarding the effect of
EPDM on the environment and wildlife in response to the notice of
filing. The comment did not address whether EPDM rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>x</INF>(C<INF>3</INF>H<INF>6</INF>)<INF>y</INF>
(C<INF>9</INF>H<INF>12</INF>)<INF>z</INF>; x=5134, y=2250, z=98) meets
the weight or value test under section 4672(a)(2)(B). 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 stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals ethylene, propylene, and butadiene constitute
more than 20 percent by weight of the materials used in the production
of EPDM rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>x</INF>(C<INF>3</INF>H<INF>6</INF>)<INF>y</INF>
(C<INF>9</INF>H<INF>12</INF>)<INF>z</INF>; x=5134, y=2250, z=98), based
on the predominant method of production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of EPDM rubber
((C2H4)x(C3H6)y(C9H12)z; x=5134, y=2250, z=98) 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.
[[Page 44895]]
(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: $9.45 per ton. The
conversion factors for the taxable chemicals used in the production of
EPDM rubber
((C<INF>2</INF>H<INF>4</INF>)<INF>x</INF>(C<INF>3</INF>H<INF>6</INF>)<INF>y</INF>
(C<INF>9</INF>H<INF>12</INF>)<INF>z</INF>; x=5134, y=2250, z=98) are
0.57 for ethylene, 0.38 for propylene, and 0.02 for butadiene. 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:
((0.57 x $9.74) + (0.38 x $9.74) + (0.02 x $9.74) = $9.45).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 4002.70.00.
(ii) Schedule B number: 4002.70.0000.
(iii) CAS number: 25034-71-3.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
23. Determination To Add Isodecyl Alcohol to the List
Exxon Mobil Corporation, an exporter of isodecyl alcohol, submitted
a petition in accordance with Rev. Proc. 2022-26 requesting to add
isodecyl alcohol to the List. According to the petition, the taxable
chemical propylene constitutes 72.00 percent by weight of the materials
used to produce isodecyl alcohol, based on the predominant method of
production.
(a) Determination. Isodecyl alcohol 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
producing isodecyl alcohol is in an oxonation reaction. Plasticizer
alcohols, including isodecyl alcohol, are derived from the oxo reaction
with branched olefins. Refinery-connected polygas units generate many
of these olefins as purified cuts or fractions.
The hydrogen used for these reactions are not produced from steam-
methane reforming. The source of hydrogen is from a Pox reactor, which
feeds liquids, not methane. The Pox process is an industrial process
that converts hydrocarbons feeds into syngas (a combination of hydrogen
and carbon monoxide gas). The hydrocarbon feed is in the liquid state.
The unit feeds a variety of liquid hydrocarbons such as paraffins,
olefins, and aromatics in the C5-C20 range, obtained from the refinery
pipestills and other chemicals units.
(2) Stoichiometric material consumption equation:
2.88 x 0.94 C<INF>3</INF>H<INF>6</INF> [propylene] + 2.88 x 0.06
C<INF>5</INF>H<INF>10</INF> [amylene] + CO [carbon monoxide] + 2
H<INF>2</INF> [hydrogen] [rarr] C<INF>10</INF>H<INF>22</INF>O [isodecyl
alcohol]
(3) Reasons for the determination: The isodecyl alcohol petition
was filed on May 1, 2025. The notice of filing summarizing the petition
and requesting comments was published in the Federal Register (90 FR
21129) on May 16, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemical propylene constitutes more than 20 percent by
weight of the materials used in the production of isodecyl alcohol,
based on the predominant method of production. Therefore, the test in
section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of isodecyl alcohol 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: $7.01 per ton. The
conversion factor for the propylene used in the production of isodecyl
alcohol is 0.72. The tax rate is calculated by multiplying the
conversion factor by the tax rate for propylene: (0.72 x $9.74 =
$7.01).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification number: CAS number: 68526-85-2.
(2) The Secretary is unable to confirm the following proposed
classification numbers:
(i) HTSUS number: 3823.70.60.00.
(ii) Schedule B number: 3823.70.6000.
24. Determination To Add Isodecyl Benzoate to the List
Exxon Mobil Corporation, an exporter of isodecyl benzoate,
submitted a petition in accordance with Rev. Proc. 2022-26 requesting
to add isodecyl benzoate to the List. According to the petition, the
taxable chemicals propylene and toluene constitute 69.10 percent by
weight of the materials used to produce isodecyl benzoate, based on the
predominant method of production.
(a) Determination. Isodecyl benzoate 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
producing isodecyl benzoate is via esterification. The isodecyl
benzoate ester is made by reacting primary isodecyl (C10) alcohol with
benzoic acid. The ester is produced by esterification of one mole of
isodecyl C10 alcohol and one mole of benzoic acid in the presence of a
catalyst.
By using excess alcohol (up to 30% molar excess of C10 alcohol) and
removing the water, the equilibrium is shifted towards the formation of
the ester. The reactants are charged into a reactor and heated up. The
reaction rate is accelerated by using, for example, tetra-n-butyl
titanate introduced at high temperature (140 [deg]C-250 [deg]C), while
removing the water formed.
Excess alcohol is distilled from the ester by vacuum prior to
neutralization and recycled into subsequent batches. The final ester is
purified by neutralizing with a base such as an aqueous solution of
sodium carbonate. The remaining excess water is distilled off and the
ester is then filtered using filter agents. The degree of purity of the
ester has a minimum 99.0 wt%.
(2) Stoichiometric material consumption equation:
2.71 C<INF>3</INF>H<INF>6</INF> [propylene] + 0.17
C<INF>5</INF>H<INF>10</INF> [amylene] + CO [carbon monoxide] + 2
H<INF>2</INF> [hydrogen] + C<INF>6</INF>H<INF>5</INF>CH<INF>3</INF>
[toluene] + 1.5 O<INF>2</INF> [oxygen] [rarr]
C<INF>17</INF>H<INF>26</INF>O<INF>2</INF> [isodecyl benzoate] + 2
H<INF>2</INF>O [water]
(3) Reasons for the determination: The isodecyl benzoate petition
was filed on May 1, 2025. The notice of filing summarizing the petition
and requesting comments was published in the Federal Register (90 FR
21130) on May 16, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals propylene and toluene constitute more than 20
percent by weight of the materials used in the production of isodecyl
benzoate, based on the predominant method of production. Therefore, the
test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
[[Page 44896]]
(5) Effective dates for addition of isodecyl benzoate 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: $7.60 per ton. The
conversion factors for the taxable chemicals used in the production of
isodecyl benzoate are 0.43 for propylene and 0.35 for toluene. 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:
((0.43 x $9.74) + (0.35 x $9.74) = $7.60).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers: Not applicable.
(2) The Secretary is unable to confirm the following proposed
classification numbers:
(i) HTSUS number: 2916.31.50.00.
(ii) Schedule B number: 2916.31.0002.
(iii) CAS number: 131298-44-7.
25. Determination To Add Isooctyl Alcohol to the List
Exxon Mobil Corporation, an exporter of isooctyl alcohol, submitted
a petition in accordance with Rev. Proc. 2022-26 requesting to add
isooctyl alcohol to the List. According to the petition, the taxable
chemical propylene constitutes 68.10 percent by weight of the materials
used to produce isooctyl alcohol, based on the predominant method of
production.
(a) Determination. Isooctyl alcohol 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
producing isooctyl alcohol is in an oxonation reaction. Plasticizer
alcohols, including isooctyl alcohol, are derived from the oxo reaction
with branched olefins. Refinery-connected polygas units generate many
of these olefins as purified cuts or fractions. For example, isooctyl
alcohol is produced from heptene, which is an isomeric mixture of C7
olefins that are derived from the reaction of propylene and butylenes.
The extent of branching in heptane depends on the reaction conditions
and feedstock ratio at the polygas units. Since these conditions are
variable, the specifications of the alcohol product may vary among
producers.
The hydrogen used for these reactions are not produced from steam-
methane reforming. The source of hydrogen is from POx reactor, which
feeds liquids, not methane. The POx process is an industrial process
that converts hydrocarbons feeds into syngas (a combination of hydrogen
and carbon monoxide gas). The hydrocarbon feed is in the liquid state.
The unit feeds a variety of liquid hydrocarbons such as paraffins,
olefins, and aromatics in the C5-C20 range, obtained from the refinery
pipestills and other chemicals units.
(2) Stoichiometric material consumption equation:
2.24 x 0.94 C<INF>3</INF>H<INF>6</INF> [propylene] + 2.24 x 0.06
C<INF>5</INF>H<INF>10</INF> [amylene] + CO [carbon monoxide] + 2
H<INF>2</INF> [hydrogen] [rarr] C<INF>8</INF>H<INF>18</INF>O [isooctyl
alcohol]
(3) Reasons for the determination: The isooctyl alcohol petition
was filed on May 1, 2025. The notice of filing summarizing the petition
and requesting comments was published in the Federal Register (90 FR
21126) on May 16, 2025. The Treasury Department and the IRS received
one non-substantive written comment regarding the importance of
evaluating the data in response to the notice of filing. The comment
did not address whether isooctyl alcohol meets the weight or value test
under section 4672(a)(2)(B). 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 stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemical propylene constitutes more than 20 percent by
weight of the materials used in the production of isooctyl alcohol,
based on the predominant method of production. Therefore, the test in
section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of isooctyl alcohol 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: $6.62 per ton. The
conversion factor for the propylene used in the production of isooctyl
alcohol is 0.68. The tax rate is calculated by multiplying the
conversion factor by the tax rate for propylene: (0.68 x $9.74 =
$6.62).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 2905.16.00.50.
(ii) Schedule B number: 2905.16.0050.
(iii) CAS number: 68526-83-0.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
26. Determination To Add Linear Nonyl Phthalate to the List
Exxon Mobil Corporation, an exporter of linear nonyl phthalate,
submitted a petition in accordance with Rev. Proc. 2022-26 requesting
to add linear nonyl phthalate to the List. According to the petition,
the taxable chemicals ethylene and orthoxylene (an isomer of xylene)
constitute 67.40 percent by weight of the materials used to produce
linear nonyl phthalate, based on the predominant method of production.
(a) Determination. Linear nonyl phthalate 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
producing linear nonyl phthalate is via esterification.
The linear nonyl phthalate di-ester is made by reacting a mix of
primary C9 alcohol with phthalic anhydride. The ester is produced by
esterification of two moles of a linear C9 alcohol with one mole of
phthalic anhydride in the presence of an acidic catalyst.
By using excess alcohol (up to 25% molar excess of C9 alcohol) and
removing the water, the equilibrium is shifted towards the formation of
the di-ester. The reactants are charged into a reactor and heated up.
The reaction rate is accelerated by using, for example, tetra-n-butyl
titanate introduced at high temperature (140 [deg]C-250 [deg]C), while
removing the water formed.
The final ester is purified by neutralizing with a base such as an
aqueous solution of sodium carbonate. Then excess alcohol is distilled
off using steam/nitrogen stripping after neutralization. The remaining
excess water is distilled off and the ester is then filtered using
filter agents.
The degree of purity of the ester is up to >99.5 wt%. The overall
formula is C<INF>26</INF>H<INF>42</INF>O<INF>4</INF> and the molecular
weight is 418 g/mole, based on an average carbon number of the alkyl
groups, with 9 carbons being the predominant number.
The linear C9 alcohol is obtained through hydroformylation of
octene. Octene is obtained through ethylene oligomerization.
Hydroformylation is the reaction of octene, at high pressure and
temperature in the presence of a catalyst, with syngas (a mixture of
carbon monoxide and hydrogen). An alcohol with one carbon atom higher
versus the starting olefin is obtained,
[[Page 44897]]
hence octene gives nonanol. The hydroformylation induces 0.3 branches
per molecule predominantly on the 2-postion carbon of the alcohol.
Phthalic anhydride is obtained through air oxidation of o.xylene.
(2) Stoichiometric material consumption equation:
8 C<INF>2</INF>H<INF>4</INF> [ethylene] + 2 CO [carbon monoxide] + 4
H<INF>2</INF> [hydrogen] + C<INF>8</INF>H<INF>10</INF> [orthoxylene] +
3 O<INF>2</INF> [oxygen] [rarr]
C<INF>26</INF>H<INF>42</INF>O<INF>4</INF> [linear nonyl phthalate] + 4
H<INF>2</INF>O [water]
(3) Reasons for the determination: The linear nonyl phthalate
petition was filed on April 8, 2025. The notice of filing summarizing
the petition and requesting comments was published in the Federal
Register (90 FR 20348) on May 13, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals ethylene and orthoxylene (an isomer of xylene)
constitute more than 20 percent by weight of the materials used in the
production of linear nonyl phthalate, based on the predominant method
of production. Therefore, the test in section 4672(a)(2)(B) is
satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of linear nonyl phthalate 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: $7.69 per ton. The
conversion factors for the taxable chemicals used in the production of
linear nonyl phthalate are 0.54 for ethylene and 0.25 for xylene. 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:
((0.54 x $9.74) + (0.25 x $9.74) = $7.69).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification number: CAS number: 68515-45-7.
(2) The Secretary is unable to confirm the following proposed
classification numbers:
(i) HTSUS number: 2917.33.00.50.
(ii) Schedule B number: 2917.33.0050.
27. Determination To Add Linear Nonyl Undecyl Phthalate to the List
Exxon Mobil Corporation, an exporter of linear nonyl undecyl
phthalate, submitted a petition in accordance with Rev. Proc. 2022-26
requesting to add linear undecyl phthalate to the List. According to
the petition, the taxable chemicals ethylene and orthoxylene (an isomer
of xylene) constitute 69.14 percent by weight of the materials used to
produce linear nonyl undecyl phthalate, based on the predominant method
of production.
(a) Determination. Linear nonyl undecyl phthalate 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
producing linear nonyl undecyl phthalate is via esterification. The
linear nonyl undecyl phthalate di-ester is made by reacting a mix of
primary C9 alcohol and primary C11 alcohol with phthalic anhydride. The
ester is produced by esterification of one mole of a linear C9 alcohol
and one mole of a linear C11 alcohol mix with one mole of phthalic
anhydride in the presence of an acidic catalyst. By using excess
alcohol (up to 25% molar excess of the alcohol mix) and removing the
water, the equilibrium is shifted towards the formation of the di-
ester. The reactants are charged into a reactor and heated up. The
reaction rate is accelerated by using, for example, tetra-n-butyl
titanate introduced at high temperature (140 [deg]C-250 [deg]C), while
removing the water formed. The final ester is purified by neutralizing
with a base such as an aqueous solution of sodium carbonate. Then
excess alcohol is distilled off using steam/nitrogen stripping after
neutralization. The remaining excess water is distilled off and the
ester is then filtered using filter agents. The degree of purity of the
ester is up to >99.5 wt%.
The overall formula is C<INF>28</INF>H<INF>46</INF>O<INF>4</INF>
and the molecular weight is 446 g/mole, based on an average carbon
number of the alkyl groups, which are C9 and C11 carbons. The linear
C9/C11 alcohols are obtained through hydroformylation of octene/decene.
octene/decene is obtained through ethylene oligomerization.
Hydroformylation is the reaction of octene/decene, at high pressure and
temperature in the presence of a catalyst, with syngas (a mixture of
carbon monoxide and hydrogen). An alcohol with one carbon atom higher
versus the starting olefin is obtained, hence octene/decene gives
nonanol/undecanol. The hydroformylation induces 0.3 branches per
molecule predominantly on the 2-postion carbon of the alcohol. Phthalic
anhydride is obtained through air oxidation of orthoxylene.
The hydrogen used for these reactions is not produced from steam-
methane reforming; the source is from a POx reactor, which feeds
liquids, not methane. The POx process is an industrial process that
converts hydrocarbons feeds into syngas (a combination of hydrogen and
carbon monoxide gas). The hydrocarbon feed is in the liquid state; it
does not feed gas (such as methane) or solids. The unit feeds a variety
of liquid hydrocarbons such as paraffins, olefins, and aromatics in the
C5-C20 range, obtained from the refinery pipestills and other chemicals
units.
(2) Stoichiometric material consumption equation:
9 C<INF>2</INF>H<INF>4</INF> [ethylene] + 2 CO [carbon monoxide] + 4
H<INF>2</INF> [hydrogen] + C<INF>8</INF>H<INF>10</INF> [orthoxylene] +
3 O<INF>2</INF> [oxygen] [rarr]
C<INF>28</INF>H<INF>46</INF>O<INF>4</INF> [linear nonyl undecyl
phthalate] + 4 H<INF>2</INF>O [water]
(3) Reasons for the determination: The linear nonyl undecyl
phthalate petition was filed on April 8, 2025. The notice of filing
summarizing the petition and requesting comments was published in the
Federal Register (90 FR 20553) on May 14, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals ethylene and orthoxylene (an isomer of xylene)
constitute more than 20 percent by weight of the materials used in the
production of linear nonyl undecyl phthalate, based on the predominant
method of production. Therefore, the test in section 4672(a)(2)(B) is
satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of linear nonyl undecyl phthalate
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: $7.89 per ton. The
conversion
[[Page 44898]]
factors for the taxable chemicals used in the production of linear
nonyl undecyl phthalate are 0.57 for ethylene and 0.24 for xylene. 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:
((0.57 x $9.74) + (0.24 x $9.74) = $7.89)
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 3812.20.10.00.
(ii) Schedule B number: 3812.20.0000.
(iii) CAS number: 68515-43-5.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
28. Determination To Add Linear Undecyl Phthalate to the List
Exxon Mobil Corporation, an exporter of linear undecyl phthalate,
submitted a petition in accordance with Rev. Proc. 2022-26 requesting
to add linear undecyl phthalate to the List. According to the petition,
the taxable chemicals ethylene and orthoxylene (an isomer of xylene)
constitute 70.72 percent by weight of the materials used to produce
linear undecyl phthalate, based on the predominant method of
production.
(a) Determination. Linear undecyl phthalate 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
producing linear undecyl phthalate di-ester is by reacting a mix of
primary C11 alcohol with phthalic anhydride. The ester is produced by
esterification of two moles of a linear C11 alcohol with one mole of
phthalic anhydride in the presence of an acidic catalyst.
By using excess alcohol (up to 25% molar excess of C11 alcohol) and
removing the water, the equilibrium is shifted towards the formation of
the di-ester. The reactants are charged into a reactor and heated up.
The reaction rate is accelerated by using, for example, tetra-n-butyl
titanate introduced at high temperature (140 [deg]C-250 [deg]C), while
removing the water formed.
The final ester is purified by neutralizing with a base such as an
aqueous solution of sodium carbonate. Then excess alcohol is distilled
off using steam/nitrogen stripping after neutralization. The remaining
excess water is distilled off and the ester is then filtered using
filter agents.
The degree of purity of the ester is up to >99.5 wt%. The overall
formula is C<INF>30</INF>H<INF>50</INF>O<INF>4</INF> and the molecular
weight is 474 g/mole, based on an average carbon number of the alkyl
groups, with 11 carbons being the predominant number.
The linear C11 alcohol is obtained through hydroformylation of
decene. Decene is obtained through ethylene oligomerization.
Hydroformylation is the reaction of decene, at high pressure and
temperature in the presence of a catalyst, with syngas (a mixture of
carbon monoxide and hydrogen). An alcohol with one carbon atom higher
versus the starting olefin is obtained, hence decene gives undecanol.
The hydroformylation induces 0.3 branches per molecule predominantly on
the 2-position carbon of the alcohol. Phthalic anhydride is obtained
through air oxidation of o.xylene.
(2) Stoichiometric material consumption equation:
10 C<INF>2</INF>H<INF>4</INF> [ethylene] + 2 CO [carbon monoxide] + 4
H<INF>2</INF> [hydrogen] + C<INF>8</INF>H<INF>10</INF> [orthoxylene] +
3 O<INF>2</INF> [oxygen] [rarr]
C<INF>30</INF>H<INF>50</INF>O<INF>4</INF> [linear undecyl phthalate] +
4 H<INF>2</INF>O [water]
(3) Reasons for the determination: The linear undecyl phthalate
petition was filed on April 8, 2025. The notice of filing summarizing
the petition and requesting comments was published in the Federal
Register (90 FR 20353) on May 13, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals ethylene and orthoxylene (an isomer of xylene)
constitute more than 20 percent by weight of the materials used in the
production of linear undecyl phthalate, based on the predominant method
of production. Therefore, the test in section 4672(a)(2)(B) is
satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of linear undecyl phthalate 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: $7.89 per ton. The
conversion factors for the taxable chemicals used in the production of
linear undecyl phthalate are 0.59 for ethylene and 0.22 for xylene. 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:
((0.59 x $9.74) + (0.22 x $9.74) = $7.89).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers: Not applicable.
(2) The Secretary is unable to confirm the following proposed
classification numbers:
(i) HTSUS number: 2917.33.00.50.
(ii) Schedule B number: 2917.33.00.50.
(iii) CAS number: 3648-20-2.
29. Determination To Add Linear Nonyl Tri-mellitate to the List
Exxon Mobil Corporation, an exporter of linear nonyl tri-mellitate,
submitted a petition in accordance with Rev. Proc. 2022-26 requesting
to add linear nonyl tri-mellitate to the List. According to the
petition, the taxable chemical ethylene constitutes 53.90 percent by
weight of the materials used to produce linear nonyl tri-mellitate,
based on the predominant method of production.
(a) Determination. Linear nonyl tri-mellitate 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 linear nonyl tri-mellitate is using an esterification
reaction. The linear nonyl tri-mellitate tri-ester is made by reacting
primary C9 alcohol with trimellitic anhydride. The ester is produced by
esterification of three moles of a linear C9 alcohol and one mole of
trimellitic anhydride in the presence of an acidic catalyst.
By using excess alcohol (up to 30% molar excess of C9 alcohol) and
removing the water, the equilibrium is shifted towards the formation of
the tri-ester. The reactants are charged into a reactor and heated up.
The reaction rate is accelerated by using, for example, tetra-n-butyl
titanate introduced at high temperature (140 [deg]C-250 [deg]C), while
removing the water formed.
Excess alcohol is distilled from the ester by vacuum prior to
neutralization and recycled into subsequent batches. The final ester is
purified by neutralizing with a base such as an aqueous solution of
sodium carbonate. The remaining excess water is distilled off and the
ester is then filtered using filter agents.
The degree of purity of the ester has a minimum 99.0 wt%. The
overall formula is C<INF>36</INF>H<INF>60</INF>O<INF>6</INF> and the
molecular weight is 589 g.mol-1, based on the carbon numbers of the
alkyl groups, with 9 carbons being the predominant number and the
average (>97% C9). The alkyl groups typically have methyl- or ethyl-
branching, with on average 0.3 branches per molecule typically found
[[Page 44899]]
on the second carbon of the alkyl chain closest to the aromatic ring.
The linear C9 alcohol is obtained through hydroformylation of
octene. Octene is obtained through ethylene oligomerization.
Hydroformylation is the reaction of ctene at high pressure and
temperature in the presence of a catalyst with syngas (a mixture of
carbon monoxide and hydrogen). An alcohol with one carbon atom higher
versus the starting olefin is obtained, hence octene gives nonanol. The
hydroformylation induces 0.3 branches per molecule predominantly on the
two-position carbon of the alcohol. Trimellitic anhydride is obtained
through air oxidation of 1,2,4-trimethylbenzene.
(2) Stoichiometric material consumption equation:
12 C<INF>2</INF>H<INF>4</INF> [ethylene] + 3 CO [carbon monoxide] + 6
H<INF>2</INF> [hydrogen] + C<INF>9</INF>H<INF>4</INF>O<INF>5</INF>
[trimellitic anhydride] [rarr]
C<INF>36</INF>H<INF>60</INF>O<INF>6</INF> [linear nonyl tri-mellitate]
+ 2 H<INF>2</INF>O [water]
(3) Reasons for the determination: The linear nonyl tri-mellitate
petition was filed on May 1, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 21125) on May 16, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemical ethylene constitutes more than 20 percent by
weight of the materials used in the production of linear nonyl tri-
mellitate, based on the predominant method of production. Therefore,
the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of linear nonyl tri-mellitate 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: $5.55 per ton. The
conversion factor for the ethylene used in the production of linear
nonyl tri-mellitate is 0.57. The tax rate is calculated by multiplying
the conversion factor by the tax rate for ethylene: (0.57 x $9.74 =
$5.55).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 2917.39.20.00.
(ii) Schedule B number: 2917.39.2000.
(iii) CAS number: 220582-53-6.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
30. Determination To Add Neo Decanoic Acid to the List
Exxon Mobil Corporation, an exporter of neo decanoic acid,
submitted a petition in accordance with Rev. Proc. 2022-26 requesting
to add neo decanoic acid to the List. According to the petition, the
taxable chemical propylene constitutes 66.20 percent by weight of the
materials used to produce neo decanoic acid, based on the predominant
method of production.
(a) Determination. Neo decanoic 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 method of
production of neo decanoic acid is Koch synthesis.
(2) Stoichiometric material consumption equation:
2.88 x 0.94 C<INF>3</INF>H<INF>6</INF> [propylene] + 2.88 x 0.06
C<INF>5</INF>H<INF>10</INF> [amylene] + CO [carbon monoxide] +
H<INF>2</INF>O [water] [rarr] C<INF>10</INF>H<INF>20</INF>O<INF>2</INF>
[neo decanoic acid]
(3) Reasons for the determination: The neo decanoic acid petition
was filed on May 1, 2025. The notice of filing summarizing the petition
and requesting comments was published in the Federal Register (90 FR
21824) on May 21, 2025. The Treasury Department and the IRS received
one non-substantive written comment cautioning against the danger of
producing the substance in response to the notice of filing. The
comment did not address whether neo decanoic acid meets the weight or
value test under section 4672(a)(2)(B). 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 stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemical propylene constitutes more than 20 percent by
weight of the materials used in the production of neo decanoic acid,
based on the predominant method of production. Therefore, the test in
section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of neo decanoic 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): July 1, 2022.
(6) Tax rate prescribed by the Secretary: $6.43 per ton. The
conversion factor for the propylene used in the production of neo
decanoic acid is 0.66. The tax rate is calculated by multiplying the
conversion factor by the tax rate for propylene: (0.66 x $9.74 =
$6.43).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification number: CAS number: 26896-20-8.
(2) The Secretary is unable to confirm the following proposed
classification numbers:
(i) HTSUS number: 2915.90.18.00.
(ii) Schedule B number: 2915.90.0000.
31. Determination To Add Neo Pentanoic Acid to the List
Exxon Mobil Corporation, an exporter of neo pentanoic acid,
submitted a petition in accordance with Rev. Proc. 2022-26 requesting
to add neo pentanoic acid to the List. According to the petition, the
taxable chemical isobutylene (an isomer of butylene) constitutes 54.90
percent by weight of the materials used to produce neo pentanoic acid,
based on the predominant method of production.
(a) Determination. Neo pentanoic 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 method of
producing neo pentanoic acid is via Koch synthesis. Isobutylene is
reacted with carbon monoxide at >1000 psig and a highly acidic (Lewis
acid) catalyst (Koch reaction) in a continuous, stirred tank reactor.
The acid is sent to a distillation tower finishing section. Light
rejects (paraffins, olefins, and light acids) are removed, prime
neopentanoic acid is recovered at high purity (>99.7 wt%), and acidic
byproducts removed.
(2) Stoichiometric material consumption equation:
C<INF>4</INF>H<INF>8</INF> [isobutylene] + CO [carbon monoxide] +
H<INF>2</INF>O [water][rarr] C<INF>5</INF>H<INF>10</INF>O<INF>2</INF>
[neo pentanoic acid]
(3) Reasons for the determination: The neo pentanoic acid petition
was filed on May 1, 2025. The notice of filing summarizing the petition
and requesting comments was published in the Federal Register (90 FR
20346) on May 13, 2025. The Treasury Department and the IRS
[[Page 44900]]
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 stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemical isobutylene (an isomer of butylene) constitutes
more than 20 percent by weight of the materials used in the production
of neo pentanoic acid, based on the predominant method of production.
Therefore, the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of neo pentanoic 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): July 1, 2022.
(6) Tax rate prescribed by the Secretary: $5.36 per ton. The
conversion factor for the butylene used in the production of neo
pentanoic acid is 0.55. The tax rate is calculated by multiplying the
conversion factor by the tax rate for butylene: (0.55 x $9.74 = $5.36).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 2915.60.50.00.
(ii) Schedule B number: 2915.60.0000.
(iii) CAS number: 75-98-9.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
32. Determination To Add Nonene to the List
Exxon Mobil Corporation, an exporter of nonene, submitted a
petition in accordance with Rev. Proc. 2022-26 requesting to add nonene
to the List. According to the petition, the taxable chemical propylene
constitutes 90.50 percent by weight of the materials used to produce
nonene, based on the predominant method of production.
(a) Determination. Nonene 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
producing nonene is oligomerization.
Nonene (C<INF>9</INF>H<INF>18</INF>) and tetramer
(C<INF>12</INF>H<INF>24</INF>) are olefins that are obtained by
oligomerization of feedstock that contains propylene. Each product
actually contains several isomeric olefins with varying degrees of
branching and different positions of the olefinic double bond.
Refinery-generated propylene is of sufficient quality to be used as the
feedstock material. The most common process initiates the reaction with
a supported phosphoric acid catalyst at temperatures ranging from 120
[deg]C to 225 [deg]C. Reaction temperature and feed composition
determine the range of olefins in a given product stream. If the
feedstock is a propylene-rich C3 stream, C9 and C12 olefins are the
dominant products. Some processes that use a mixed C3/C4 feed generate
a spectrum of products that also includes heptene (C7) and octene (C8).
Distillation separates the mix into the desired product fractions.
Nonene and tetramer have distillation ranges of 127 [deg]C-149 [deg]C
and 182 [deg]C-215 [deg]C, respectively. Assuming 83 percent and 79
percent of theoretical yield for production of nonene and tetramer,
respectively, 1.21 and 1.27 units of propylene are consumed per unit of
nonene and tetramer produced, respectively.
(2) Stoichiometric material consumption equation:
2.88 x 0.94 C<INF>3</INF>H<INF>6</INF> [propylene] + 2.88 x 0.06
C<INF>5</INF>H<INF>10</INF> [amylene] [rarr]
C<INF>9</INF>H<INF>18</INF> [nonene]
(3) Reasons for the determination: The nonene petition was filed on
May 1, 2025. The notice of filing summarizing the petition and
requesting comments was published in the Federal Register (90 FR 21826)
on May 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemical propylene constitutes more than 20 percent by
weight of the materials used in the production of nonene, based on the
predominant method of production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of nonene 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: $8.77 per ton. The
conversion factor for the propylene used in the production of nonene is
0.90. The tax rate is calculated by multiplying the conversion factor
by the tax rate for propylene: (0.90 x $9.74 = $8.77).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification number: CAS number: 68526-55-6.\5\
---------------------------------------------------------------------------
\5\ The Notice of Filing for propylene erroneously stated that
the CAS number is ``68526-55-63.'' This error is corrected here.
---------------------------------------------------------------------------
(2) The Secretary is unable to confirm the following proposed
classification numbers:
(i) HTSUS number: 2901.29.50.00.
(ii) Schedule B number: 2901.29.6000.
33. Determination To Add Regular Butyl Rubber ((C4H8)x(C5H8)y; x=7036,
y=88) to the List
Exxon Mobil Corporation, an exporter of regular butyl rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
; x=7036, y=88), submitted a petition in accordance with Rev. Proc.
2022-26 requesting to add regular butyl rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
; x=7036, y=88) to the List. According to the petition, the taxable
chemical isobutylene (an isomer of butylene) constitutes 98.50 percent
by weight of the materials used to produce regular butyl rubber, based
on the predominant method of production.
(a) Determination. Regular butyl rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
; x=7036, y=88) 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
producing regular butyl rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
; x=7036, y=88) is via cationic copolymerization of isobutylene with
isoprene in the presence of a catalyst. The catalyst system used is
typically composed of aluminum chloride, boron trifluoride or similar
with an initiator dissolved in a methyl chloride solvent. Monomer feed
of isobutylene and isoprene dissolved in a methyl chloride solvent are
fed to a reactor operated at approximately -100 [deg]C to control the
rapid exothermic polymerization reaction generating a high molecular
weight regular butyl rubber polymer. To obtain this high molecular
weight polymer, it is necessary for the feed monomers to be as pure as
possible as well as ensuring that the feed system stays as dry as
possible. The methyl chloride and unreacted monomers are flashed
overhead and recycled back to the feed system while the polymer is
precipitated out as a solid which is baled and packaged.
[[Page 44901]]
(2) Stoichiometric material consumption equation:
7036 C<INF>4</INF>H<INF>8</INF> [isobutylene] + 88
C<INF>5</INF>H<INF>8</INF> [isoprene] [rarr] [7036
C<INF>4</INF>H<INF>8</INF> + 88 C<INF>5</INF>H<INF>8</INF>] [butyl
rubber]
(3) Reasons for the determination: The regular butyl rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
; x=7036, y=88) petition was filed on April 8, 2025. The notice of
filing summarizing the petition and requesting comments was published
in the Federal Register (90 FR 20347) on May 13, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemical isobutylene (an isomer of butylene) constitutes
more than 20 percent by weight of the materials used in the production
of regular butyl rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
; x=7036, y=88), based on the predominant method of production.
Therefore, the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of regular butyl rubber
((C4H8)x(C5H8)y; x=7036, y=88) 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: $9.64 per ton. The
conversion factor for the butylene used in the production of regular
butyl rubber
((C<INF>4</INF>H<INF>8</INF>)<INF>x</INF>(C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>
; x=7036, y=88) is 0.99. The tax rate is calculated by multiplying the
conversion factor by the tax rate for butylene: (0.99 x $9.74 = $9.64).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 4002.31.0000.
(ii) Schedule B number: 4002.31.0000.
(iii) CAS number: 9010-85-9.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
34. Determination To Add Tridecyl Alcohol to the List
Exxon Mobil Corporation, an exporter of tridecyl alcohol, submitted
a petition in accordance with Rev. Proc. 2022-26 requesting to add
tridecyl alcohol to the List. According to the petition, the taxable
chemical propylene constitutes 75.90 percent by weight of the materials
used to produce tridecyl alcohol, based on the predominant method of
production.
(a) Determination. Tridecyl alcohol 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
producing tridecyl alcohol is oxonation.
Tridecyl alcohol is derived from the oxo reaction with branched
olefins. Refinery-connected polygas units generate many of these
olefins as purified cuts or fractions.
Most commercial plants for hydroformylation of higher olefins use
only cobalt hydrocarbonyl or modified cobalt-phosphine catalysts.
Separation of Rh catalysts from higher aldehydes or alcohols is more
difficult and expensive. In most cases for the plasticizer and
detergent alcohol ranges (C6-C15), producers hydrogenate the aldehydes,
which have no commercial significance, to alcohols.
(2) Stoichiometric material consumption equation:
3.85 x 0.94 C<INF>3</INF>H<INF>6</INF> [propylene] + 3.85 x 0.06
C<INF>5</INF>H<INF>10</INF> [amylene] + CO [carbon monoxide] + 2
H<INF>2</INF> [hydrogen] [rarr] C<INF>13</INF>H<INF>28</INF>O [tridecyl
alcohol]
(3) Reasons for the determination: The tridecyl alcohol petition
was filed on May 1, 2025. The notice of filing summarizing the petition
and requesting comments was published in the Federal Register (90 FR
21824) on May 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemical propylene constitutes more than 20 percent by
weight of the materials used in the production of tridecyl alcohol,
based on the predominant method of production. Therefore, the test in
section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of tridecyl alcohol 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: $7.40 per ton. The
conversion factor for the propylene used in the production of tridecyl
alcohol is 0.76. The tax rate is calculated by multiplying the
conversion factor by the tax rate for propylene: (0.76 x $9.74 =
$7.40).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification number: CAS number: 68526-86-3.
(2) The Secretary is unable to confirm the following proposed
classification numbers:
(i) HTSUS number: 3823.70.60.00.
(ii) Schedule B number: 3823.70.6000.
35. Determination To Add Tri-isononyl Tri-mellitate to the List
Exxon Mobil Corporation, an exporter of tri-isononyl tri-mellitate,
submitted a petition in accordance with Rev. Proc. 2022-26 requesting
to add tri-isononyl tri-mellitate to the List. According to the
petition, the taxable chemical propylene constitutes 47.30 percent by
weight of the materials used to produce tri-isononyl tri-mellitate,
based on the predominant method of production.
(a) Determination. Tri-isononyl tri-mellitate 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
producing tri-isononyl tri-mellitate is via esterification.
This process can be readily carried out in heated kettles with
agitation and provision for water takeoff. Esterification catalysts
(e.g., sulfuric acid or p-toluenesulfonic acid) speed the reaction and
are neutralized, washed, and then removed. The purity requirements for
commercial plasticizers are very high; phthalate esters are usually
colorless and are mostly odorless. In the case of phthalates, the
esterification is carried out through the reaction of phthalic
anhydride and 2-ethylhexanol to produce dioctyl phthalate (DOP).
This reaction usually requires an excess of alcohol, which is
readily recycled. Analogous syntheses yield aliphatic dicarboxylic acid
esters, benzoates, and trimellitates.
The tri-isononyl tri-mellitate tri-ester is made by reacting
primary isononyl (C9) alcohol with trimellitic anhydride. The ester is
produced by esterification of three moles of isononyl C9 alcohol and
one mole of trimellitic anhydride in the presence of a catalyst.
By using excess alcohol (up to 30% molar excess of C9 alcohol) and
removing the water, the equilibrium is shifted towards the formation of
the tri-
[[Page 44902]]
ester. The reactants are charged into a reactor and heated up. The
reaction rate is accelerated by using, for example, tetra-n-butyl
titanate introduced at high temperature (140 [deg]C-250 [deg]C), while
removing the water formed.
Excess alcohol is distilled from the ester by vacuum prior to
neutralization and recycled into subsequent batches. The final ester is
purified by neutralizing with a base such as an aqueous solution of
sodium carbonate. The remaining excess water is distilled off and the
ester is then filtered using filter agents. The degree of purity of the
ester has a minimum 99.0 wt%.
(2) Stoichiometric material consumption equation:
7.22 C<INF>3</INF>H<INF>6</INF> [propylene] + 0.46
C<INF>5</INF>H<INF>10</INF> [amylene] + 3 CO [carbon monoxide] + 6
H<INF>2</INF> [hydrogen] + C<INF>9</INF>H<INF>4</INF>O<INF>5</INF>
[trimellitic anhydride] [rarr]
C<INF>36</INF>H<INF>60</INF>O<INF>6</INF> [tri-isononyl trimellitate] +
2 H<INF>2</INF>O [water]
(3) Reasons for the determination: The tri-isononyl tri-mellitate
petition was filed on May 1, 2025. The notice of filing summarizing the
petition and requesting comments was published in the Federal Register
(90 FR 21827) on May 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemical propylene constitutes more than 20 percent by
weight of the materials used in the production of tri-isononyl tri-
mellitate, based on the predominant method of production. Therefore,
the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of tri-isononyl tri-mellitate 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: $5.06 per ton. The
conversion factor for the propylene used in the production of tri-
isononyl tri-mellitate is 0.52. The tax rate is calculated by
multiplying the conversion factor by the tax rate for propylene: (0.52
x $9.74 = $5.06).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 2917.39.20.00.
(ii) Schedule B number: 2917.39.2000.
(iii) CAS number: 53894-23-8.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
36. Determination To Add Di-isobutylene to the List
TPC Group, Inc., an exporter of di-isobutylene, submitted a
petition in accordance with Rev. Proc. 2022-26 requesting to add di-
isobutylene to the List. According to the petition, the taxable
chemical isobutylene (an isomer of butylene) constitutes 100 percent by
weight of the materials used to produce di-isobutylene, based on the
predominant method of production.
(a) Determination. Di-isobutylene 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
producing di-isobutylene is the cationic dimerization (polymerization)
of isobutylene monomers. An acid catalyst (typically a sulfonic acid
resin) and polar moderator are used to generate a stable cation on the
tertiary carbon of isobutylene. This cation induces a chain growth
dimerization that incorporates isobutylene monomer. The catalyst is not
a component of the resulting di-isobutylene.
(2) Stoichiometric material consumption equation:
2 C<INF>4</INF>H<INF>8</INF> (isobutylene) [rarr]
C<INF>8</INF>H<INF>16</INF> (di-isobutylene)
(3) Reasons for the determination: The di-isobutylene petition was
filed on April 8, 2025. The notice of filing summarizing the petition
and requesting comments was published in the Federal Register (90 FR
20352) on May 13, 2025. The Treasury Department and the IRS received
one non-substantive written comment on the necessity of the filing to
understand its impact 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 stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemical butylene constitutes more than 20 percent by
weight of the materials used in the production of di-isobutylene, based
on the predominant method of production. Therefore, the test in section
4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of di-isobutylene 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 Secretary: $9.74 per ton. The
conversion factor for the isobutylene (an isomer of butylene) used in
the production of di-isobutylene is 1.00. The tax rate is calculated by
multiplying the conversion factor by the tax rate for butylene: (1.00 x
$9.74 = $9.74).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification number: CAS number: 25167-70-8.
(2) The Secretary is unable to confirm the following proposed
classification numbers:
(i) HTSUS number: 2901.29.1050.
(ii) Schedule B number: 2901.29.6000.
37. Determination To Add Polyisobutylene to the List
TPC Group, Inc., an exporter of polyisobutylene, submitted a
petition in accordance with Rev. Proc. 2022-26 requesting to add
polyisobutylene to the List. According to the petition, the taxable
chemical isobutylene (an isomer of butylene) constitutes 100 percent by
weight of the materials used to produce polyisobutylene, based on the
predominant method of production.
(a) Determination. Polyisobutylene 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
producing polyisobutylene is the cationic polymerization of isobutylene
monomers. A Lewis acid catalyst and proton donating initiator are used
to generate a stable cation on the tertiary carbon of isobutylene. This
cation induces a chain growth polymerization that continues to transfer
the cation to the end of the polymer chain making it available for
further incorporation of isobutylene monomer. The size of the polymer
is dictated by the reaction temperature such that the lower the
temperature the larger the polymer.
(2) Stoichiometric material consumption equation:
n C<INF>4</INF>H<INF>8</INF> (isobutylene) [rarr]
(C<INF>4</INF>H<INF>8</INF>)<INF>n</INF> (polyisobutylene)
(3) Reasons for the determination: The polyisobutylene petition was
filed on February 14, 2025. The notice of filing
[[Page 44903]]
summarizing the petition and requesting comments was published in the
Federal Register (90 FR 14521) on April 2, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemical isobutylene (an isomer of butylene) constitutes
more than 20 percent by weight of the materials used in the production
of polyisobutylene, based on the predominant method of production.
Therefore, the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of polyisobutylene 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 Secretary: $9.74 per ton. The
conversion factor for the butylene used in the production of
polyisobutylene is 1.00. The tax rate is calculated by multiplying the
conversion factor by the tax rate for butylene: (1.00 x $9.74 = $9.74).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 3902.20.10.00 and 3902.20.50.00.
(ii) Schedule B number: 3902.20.1000 and 3902.20.5000.
(iii) CAS number: 9003-27-4.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
38. Determination To Add Styrene-acrylonitrile ((C3H3N)a-(C8H8)s;
a=0.26, s=0.74) to the List
Trinseo LLC, an importer and exporter of styrene-acrylonitrile
((C<INF>3</INF>H<INF>3</INF>N)<INF>a</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>s</INF>; a=0.26, s=0.74), also known
as ``SAN,'' submitted a petition in accordance with Rev. Proc. 2022-26
requesting to add SAN to the List. According to the petition, the
taxable chemicals propylene, ammonia, benzene, and ethylene constitute
88.27 percent by weight of the materials used to produce SAN, based on
the predominant method of production.
(a) Determination. Styrene-acrylonitrile
((C<INF>3</INF>H<INF>3</INF>N)<INF>a</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>s</INF>; a=0.26, s=0.74) 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
producing SAN is through free radical, random copolymerization of 100
percent of the acrylonitrile and styrene monomers. Low levels of
unreacted monomers remain bound within the polymer matrix as
``residual'' components of the product as sold or imported.
(2) Stoichiometric material consumption equation:
a C<INF>3</INF>H<INF>6</INF> (propylene) + a NH<INF>3</INF> (ammonia) +
3/2a O<INF>2</INF> + s C<INF>6</INF>H<INF>6</INF> (benzene) + s
C<INF>2</INF>H<INF>4</INF> (ethylene) [rarr]
(C<INF>3</INF>H<INF>3</INF>N)<INF>a</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>s</INF> (SAN) + 3a H<INF>2</INF>O + s
H<INF>2</INF> (hydrogen); a=0.26, s=0.74
(3) Reasons for the determination: The SAN petition was filed on
February 14, 2025. The notice of filing summarizing the petition and
requesting comments was published in the Federal Register (90 FR 14693)
on April 3, 2025, and a correction was published in the Federal
Register (90 FR 19246) on May 6, 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 determination. A review of the stoichiometric material
consumption equation and other information in the petition shows that
the taxable chemicals propylene, ammonia, benzene, and ethylene
constitute more than 20 percent by weight of the materials used in the
production of SAN, based on the predominant method of production.
Therefore, the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of SAN 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, 2024.
(6) Tax rate prescribed by the Secretary: $9.91 per ton. The
conversion factors for the taxable chemicals used in the production of
SAN are 0.12 for propylene, 0.05 for ammonia, 0.64 for benzene, and
0.23 for ethylene. 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: ((0.12 x $9.74) + (0.05 x $5.28) + (0.64 x
$9.74) + (0.23 x $9.74) = $9.91).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 3903.20.0000 (Pellets).
(ii) Schedule B number: 3903.20.0000 (Pellets).
(iii) CAS number: 9003-54-7.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
39. Determination To Add Acrylonitrile Butadiene Styrene ((C3H3N)a-
(C4H6)b-(C8H8)s; a=0.16, b=0.10, s=0.74) to the List
Trinseo LLC, an importer and exporter of acrylonitrile butadiene
styrene ((C<INF>3</INF>H<INF>3</INF>N)<INF>a</INF>-
(C<INF>4</INF>H<INF>6</INF>)<INF>b</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>s</INF>; a=0.16, b=0.10, s=0.74), also
known as ``ABS,'' submitted a petition in accordance with Rev. Proc.
2022-26 requesting to add ABS to the List. According to the petition,
the taxable chemicals propylene, ammonia, butadiene, benzene, and
ethylene constitute 92.40 percent by weight of the materials used to
produce ABS, based on the predominant method of production.
(a) Determination. Acrylonitrile butadiene styrene
((C<INF>3</INF>H<INF>3</INF>N)<INF>a</INF>-
(C<INF>4</INF>H<INF>6</INF>)<INF>b</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>s</INF>; a=0.16, b=0.10, s=0.74) 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
producing ABS is through free radical, random copolymerization of 100
percent of the acrylonitrile, butadiene, and styrene monomers. Low
levels of unreacted monomers remain bound within the polymer matrix as
``residual'' components of the product as sold or imported.
(2) Stoichiometric material consumption equation:
a C<INF>3</INF>H<INF>6</INF> (propylene) + a NH<INF>3</INF> (ammonia) +
3/2a O<INF>2</INF> + b C<INF>4</INF>H<INF>6</INF> (butadiene) + s
C<INF>6</INF>H<INF>6</INF> (benzene) + s C<INF>2</INF>H<INF>4</INF>
(ethylene) [rarr] (C<INF>3</INF>H<INF>3</INF>N)<INF>a</INF>-
(C<INF>4</INF>H<INF>6</INF>)<INF>b</INF>-
(C<INF>8</INF>H<INF>8</INF>)<INF>s</INF> (ABS) + 3a H<INF>2</INF>O
(water) + s H<INF>2</INF> (hydrogen); a=0.16, b=0.10, s=0.74
(3) Reasons for the determination: The ABS petition was filed on
February 14, 2025. The notice of filing summarizing the petition and
requesting comments was published in the Federal Register (90 FR 14687)
on April 3, 2025, and a correction was published in the Federal
Register (90 FR 19245) on May 6, 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
[[Page 44904]]
determination. A review of the stoichiometric material consumption
equation and other information in the petition shows that the taxable
chemicals propylene, ammonia, butadiene, benzene, and ethylene
constitute more than 20 percent by weight of the materials used in the
production of ABS, based on the predominant method of production.
Therefore, the test in section 4672(a)(2)(B) is satisfied.
(4) Date of determination: September 16, 2025.
(5) Effective dates for addition of ABS 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, 2024.
(6) Tax rate prescribed by the Secretary: $9.90 per ton. The
conversion factors for the taxable chemicals used in the production of
ABS are 0.07 for propylene, 0.03 for ammonia, 0.06 for butadiene, 0.64
for benzene, and 0.23 for ethylene. The tax rate is calculated by
adding the products of the conversion factor for each taxable chemical
and the tax rate that chemical: ((0.07 x $9.74) + (0.03 x $5.28) +
(0.06 x $9.74) + (0.64 x $9.74) + (0.23 x $9.74) = $9.90).
(b) Classification numbers.
(1) The Secretary has no basis to object to the following proposed
classification numbers:
(i) HTSUS number: 3903.30.0000 (Pellets).
(ii) Schedule B number: 3903.30.0000 (Pellets).
(iii) CAS number: 9003-56-9.
(2) The Secretary is unable to confirm the following proposed
classification numbers: Not applicable.
Krishna P. Vallabhaneni,
Tax Legislative Counsel.
[FR Doc. 2025-17975 Filed 9-16-25; 8:45 am]
BILLING CODE 4830-01-P
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</html>Indexed from Federal Register on September 17, 2025.
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