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Effective July 1, 2022, excise taxes are reinstated on certain chemicals and imported chemical substances. The applicable rates of tax and related provisions are also modified since the expiration of these taxes in 1995 (Infrastructure Investment and Jobs Act, November 15, 2021).
Frequently asked questions: Superfund chemical excise taxes
How to report
Report and deposit these taxes quarterly with both:
When to pay
You must deposit the Superfund chemical excise tax twice a month. A semimonthly period is the first fifteen (15) days of a calendar month or the portion of a calendar month following the 15th day of the month.
How to pay
Make deposits payments with the Electronic Federal Tax Payment System (EFTPS).
Notice of proposed rulemaking
The proposed regulations provide definitions and special rules relating to Superfund chemical excise taxes imposed on taxable chemicals and imported substances. The proposed regulations affect manufacturers, producers and importers that sell or use taxable chemicals and importers that sell or use taxable substances. Taxpayers may rely on the proposed regulations prior to the date final regulations are published in the Federal Register provided that they follow the proposed regulations in their entirety (as applicable) and in a consistent manner.
List of taxable substances and tax rates
The initial list of taxable substances on July 1, 2022, includes the list of taxable substances in Internal Revenue Code Section 4672 and the list of taxable substances in Notice 2021-66 PDF. The list of taxable substances is subject to change as substances are added to or removed from the list of taxable substances under Internal Revenue Code Section 4672(a).
The Secretary may prescribe tax rates for taxable substances and has prescribed rates for some of the taxable substances. Importers are not required to use the prescribed rates for the tax under Internal Revenue Code Section 4671, and may calculate their own rates.
See the Form 6627 instructions for the updated list of taxable substances, which includes tax rates.
Requesting changes to list of taxable substances
Procedures to request an IRS determination to add or remove a substance from the list of taxable substances under Internal Revenue Code Section 4672(a) are in Revenue Procedure 2022-26 PDF.
Revenue Procedure 2023-20 PDF modifies Revenue Procedure 2022-26 for the date on which a taxable substance is added to the list of taxable substances for purposes of refund claims under Internal Revenue Code Section 4662(e).
Changes to the list of substances
Information from Notices of Determination making changes to the list of taxable substances in Internal Revenue Code Section 4672 and links to such Notices of Determination are provided below.
For a substance that is added to the list of taxable substances, importers of such substance are subject to the tax on taxable substances under Internal Revenue Code Section 4671 beginning on the effective date provided in the Notice of Determination. When filing out a Form 6627, an importer may use the prescribed tax rate provided in the Notice of Determination.
New substance(s)added to the list of taxable substances:
| Substance | Rate/Ton ($) | Effective date for Section 4671 Tax | Effective date for Section 4662(e) Refund Claims | Notice of determination |
|---|---|---|---|---|
| Polyoxymethylene | 3.65 | 10/1/2024 | 7/1/2022 | IRS Notice 2024-50 |
| Polyphenylene sulfide | 14.50 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
| Cellulose acetate (degree of substitution = 1.5–2.0) | 1.65 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
| 4,4′-isopropylidenediphenol-epichlorohydrin copolymer | 14.13 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
| Nylon 6 | 14.77 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
| Caprolactam | 14.77 | 1/1/2026 | 1/1/2023 | IRS Notice 2025-41 |
| Methyl ethyl ketoxime | 11.41 | 1/1/2026 | 1/1/2023 | IRS Notice 2025-41 |
| Iso-butanol | 7.07 | 1/1/2026 | 4/1/2023 | IRS Notice 2025-41 |
| Diethylene glycol monomethyl ether | 5.47 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
| Ethylene glycol phenyl ether | 10.42 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
| Methoxytriglycol | 5.66 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
| Propylene glycol methyl ether acetate | 8.85 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
| Propylene glycol methyl ether | 10.58 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
| Propylene glycol n-propyl ether | 10.43 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
| Propylene glycol phenyl ether | 13.16 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
| Di-isobutyl carbinol | 8.57 | 1/1/2026 | 1/1/2024 | IRS Notice 2025-41 |
| Di-isobutyl ketone | 8.67 | 1/1/2026 | 1/1/2024 | IRS Notice 2025-41 |
| Methyl isobutyl carbinol | 7.99 | 1/1/2026 | 1/1/2024 | IRS Notice 2025-41 |
| Cyanuric acid | 2.11 | 1/1/2026 | 10/1/2024 | IRS Notice 2025-41 |
| Potassium bicarbonate | 0.25 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
| Potassium carbonate | 0.36 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
| Sodium chlorite | 2.35 | 1/1/2026 | 7/1/2022 | IRS Notice 2025-41 |
Form 637 registration for superfund chemical taxes
To apply to participate in tax-free sales of intermediate hydrocarbon streams containing organic taxable chemicals or tax-free inventory exchanges of taxable chemicals, file Form 637, Application for Registration (For Certain Excise Tax Activities) with activity letter G.