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26 U.S.C. 4672: Definitions and special rulesText contains those laws in effect through Public Law 119-120 (October 7, 2026).
From Title 26-INTERNAL REVENUE CODECHAPTER 38-ENVIRONMENTAL TAXES

§4672. Definitions and special rules

(a)  Taxable substance

For purposes of this subchapter⁠—

(1)  In general

The term “taxable substance” means any substance which, at the time of sale or use by the importer, is listed as a taxable substance by the Secretary for purposes of this subchapter.

(2)  Determination of substances on list

A substance shall be listed under paragraph (1) if⁠—

(A)  the substance is contained in the list under paragraph (3), or

(B)  the Secretary determines, in consultation with the Administrator of the Environmental Protection Agency and the Commissioner of U.S. Customs and Border Protection, that taxable chemicals constitute more than 20 percent of the weight (or more than 20 percent of the value) of the materials used to produce such substance (determined on the basis of the predominant method of production).

If an importer or exporter of any substance requests that the Secretary determine whether such substance be listed as a taxable substance under paragraph (1) or be removed from such listing, the Secretary shall make such determination within 180 days after the date the request was filed.

(3)  Initial list of taxable substances

CumeneMethylene chloride
StyrenePolypropylene
Ammonium nitratePropylene glycol
Nickel oxideFormaldehyde
Isopropyl alcoholAcetone
Ethylene glycolAcrylonitrile
Vinyl chlorideMethanol
Polyethylene resins, totalPropylene oxide
PolybutadienePolypropylene resins
Styrene-butadiene, latexEthylene oxide
Styrene-butadiene, snpfEthylene dichloride
Synthetic rubber, not containing fillersCyclohexane
UreaIsophthalic acid
FerronickelMaleic anhydride
Ferrochromium nov 3 pctPhthalic anhydride
Ferrochrome ov 3 pct. carbonEthyl methyl ketone
Unwrought nickelChloroform
Nickel waste and scrapCarbon tetrachloride
Wrought nickel rods and wireChromic acid
Nickel powdersHydrogen peroxide
Phenolic resinsPolystyrene homo­polymer resins
Polyvinylchloride resinsMelamine
Polystyrene resins and copolymersAcrylic and methacrylic acid resins
Ethyl alcohol for nonbeverage useVinyl resins
EthylbenzeneVinyl resins, NSPF.

(4)  Modifications to list

The Secretary shall add to the list under paragraph (3) substances which meet either the weight or value tests of paragraph (2)(B) and may remove from such list only substances which meet neither of such tests.

(b)  Other definitions

For purposes of this subchapter⁠—

(1)  Importer

The term “importer” means the person entering the taxable substance for consumption, use, or warehousing.

(2)  Taxable chemicals; United States

The terms “taxable chemical” and “United States” have the respective meanings given such terms by section 4662(a).

(c)  Disposition of revenues from Puerto Rico and the Virgin Islands

The provisions of subsections (a)(3) and (b)(3) of section 7652 shall not apply to any tax imposed by section 4671.

(Added Pub. L. 99–499, title V, § 515(a) , Oct. 17, 1986 , 100 Stat. 1768 ; amended Pub. L. 100–647, title II, § 2001(b) , Nov. 10, 1988 , 102 Stat. 3594 ; Pub. L. 114–125, title VIII, § 802(d)(2) , Feb. 24, 2016 , 130 Stat. 210 ; Pub. L. 117–58, div. H, title II, § 80201(c)(1) , Nov. 15, 2021 , 135 Stat. 1330 .)

Editorial Notes

Amendments

2021⁠—Subsec. (a)(2)(B). Pub. L. 117–58 substituted “20 percent” for “50 percent” in two places.

1988⁠—Subsec. (a)(2). Pub. L. 100–647, § 2001(b)(2), inserted at end “If an importer or exporter of any substance requests that the Secretary determine whether such substance be listed as a taxable substance under paragraph (1) or be removed from such listing, the Secretary shall make such determination within 180 days after the date the request was filed.”

Subsec. (a)(2)(B). Pub. L. 100–647, § 2001(b)(1), inserted “(or more than 50 percent of the value)” after “weight”.

Subsec. (a)(4). Pub. L. 100–647, § 2001(b)(3), amended par. (4) generally. Prior to amendment, par. (4) read as follows:

“(A) In general.⁠—The Secretary may add substances to or remove substances from the list under paragraph (3) (including items listed by reason of paragraph (2)) as necessary to carry out the purposes of this subchapter.

“(B) Authority to add substances to list based on value.⁠—The Secretary may, to the extent necessary to carry out the purposes of this subchapter, add any substance to the list under paragraph (3) if such substance would be described in paragraph (2)(B) if ‘value’ were substituted for ‘weight’ therein.”

Statutory Notes and Related Subsidiaries

Change of Name

“Commissioner of U.S. Customs and Border Protection” substituted for “Commissioner of Customs” in subsec. (a)(2)(B) on authority of section 802(d)(2) of Pub. L. 114–125, set out as a note under section 211 of Title 6, Domestic Security.

Effective Date of 2021 Amendment

Amendment by Pub. L. 117–58 effective July 1, 2022, see section 80201(d) of Pub. L. 117–58, set out as a note under section 4661 of this title.

Effective Date of 1988 Amendment

Amendment by Pub. L. 100–647 effective, except as otherwise provided, as if included in the provision of the Superfund Revenue Act of 1986, Pub. L. 99–499, title V, to which it relates, see section 2001(e) of Pub. L. 100–647, set out as a note under section 56 of this title.

Effective Date

Section effective Jan. 1, 1989, see section 515(c) of Pub. L. 99–499, set out as a note under section 4671 of this title.

Transfer of Functions

For transfer of functions, personnel, assets, and liabilities of the United States Customs Service of the Department of the Treasury, including functions of the Secretary of the Treasury relating thereto, to the Secretary of Homeland Security, and for treatment of related references, see sections 203(1), 551(d), 552(d), and 557 of Title 6, Domestic Security, and the Department of Homeland Security Reorganization Plan of November 25, 2002, as modified, set out as a note under section 542 of Title 6. For establishment of U.S. Customs and Border Protection in the Department of Homeland Security, treated as if included in Pub. L. 107–296 as of Nov. 25, 2002, see section 211 of Title 6, as amended generally by Pub. L. 114–125, and section 802(b) of Pub. L. 114–125, set out as a note under section 211 of Title 6.

Presumption As a Taxable Substance for Prior Determinations

Pub. L. 117–58, div. H, title II, § 80201(c)(2), Nov. 15, 2021, 135 Stat. 1330, provided that:

“Except as otherwise determined by the Secretary of the Treasury (or the Secretary’s delegate), any substance which was determined to be a taxable substance by reason of section 4672(a)(2) of the Internal Revenue Code of 1986 prior to the date of enactment of this Act [Nov. 15, 2021] shall continue to be treated as a taxable substance for purposes of such section after such date.”

Publication of Initial List

Pub. L. 117–58, div. H, title II, § 80201(c)(3), Nov. 15, 2021, 135 Stat. 1330, provided that:

“Not later than January 1, 2022, the Secretary of the Treasury (or the Secretary’s delegate) shall publish an initial list of taxable substances under section 4672(a) of the Internal Revenue Code of 1986.”