Reinstated July 1, 2022, the Superfund chemical excise taxes apply to 42 taxable chemicals (§ 4661) and 151+ imported taxable substances (§ 4671). They're computed on Form 6627 and reported on Form 720 as IRS Nos. 54 and 17. EasyFile720 handles the worksheet, the deposit schedule, and the e-file.
The Superfund chemical excise taxes are two environmental excise taxes under IRC §§ 4661–4672, reinstated by the Infrastructure Investment and Jobs Act effective July 1, 2022 and scheduled to run through December 31, 2031. One taxes the sale or use of 42 listed chemicals; the other taxes imported substances made from them. Both are computed on Form 6627 and reported on Form 720 (IRS Nos. 54 and 17), and both generally require semimonthly deposits.
The Infrastructure Investment and Jobs Act brought these taxes back on July 1, 2022 after a long lapse, and doubled the old per-ton chemical rates. They are scheduled to run through December 31, 2031.
The § 4661 tax hits the sale or use of 42 listed taxable chemicals (IRS No. 54). The § 4671 tax hits imported taxable substances made from those chemicals (IRS No. 17). Many filers owe one but not the other.
For taxable chemicals, the manufacturer, producer, or importer pays the § 4661 tax. For imported taxable substances, the importer pays the § 4671 tax. Both are reported on Form 720 with Form 6627 attached.
Unlike most Form 720 lines, Superfund taxes generally require semimonthly EFTPS deposits on top of the quarterly return, plus the Form 6627 worksheet. EasyFile720 tracks the deposit schedule so you don't miss a period.
There are two separate Superfund chemical excise taxes. EasyFile720 computes both on Form 6627 and reports them on Form 720.
| Tax | Rate basis | IRC | IRS No. |
|---|---|---|---|
| Taxable chemicals (sale/use) | $0.44 – $9.74 per ton (varies by chemical; 42 listed) | § 4661 | 54 |
| Imported taxable substances | Composition-based; 10% of appraised value if not computed (151+ listed) | § 4671 | 17 |
Per-chemical and per-substance rates are listed in the Form 6627 instructions; the IRS periodically adds substances to the § 4671 list. Source: IRS Superfund chemical excise tax FAQs & Form 6627.
In Q2 2026 a producer sells 2,000 tons of a chemical taxed at the top $9.74/ton rate and 500 tons of one at the bottom $0.44/ton rate, and imports a taxable substance with a $100,000 appraised value (using the 10% default).
Chemicals (No. 54): (2,000 × $9.74) + (500 × $0.44) = $19,480 + $220 = $19,700. Imported substance (No. 17): $100,000 × 10% = $10,000.
Quarterly tax: $19,700 + $10,000 = $29,700 — across IRS Nos. 54 and 17. (Each chemical's exact per-ton rate is on Form 6627.)
Not every gallon or ton is taxed at full freight. Two routes can lower what you owe — verify specifics against § 4662 and the Form 6627 instructions.
Certain uses of a taxable chemical are exempt or generate a credit — for example methane or butane used as a fuel, and chemicals used to produce fertilizer, animal feed, or qualifying motor fuel. The full list of exempt uses is in § 4662 and the Form 6627 instructions.
Tax paid on a chemical or substance that is later exported — or otherwise overpaid — can generate a credit or refund. Claims are made on Form 720 Schedule C or Form 8849, supported by the Form 6627 detail.
Compute on Form 6627, report under IRS Nos. 54 & 17, and stay on the semimonthly deposit schedule — EasyFile720 manages all of it.
Identify taxable chemicals & substances
Determine which of the 42 taxable chemicals (§ 4661) you sold or used, and which imported taxable substances (§ 4671) you brought into the U.S. this quarter.
Compute the tax on Form 6627
Form 6627 (Environmental Taxes) is the worksheet: apply the per-ton rate to each chemical and the composition-based (or 10% default) rate to each imported substance.
Carry totals to Form 720 (Nos. 54 & 17)
EasyFile720 carries your Form 6627 totals to Form 720 — IRS No. 54 (taxable chemicals) and IRS No. 17 (imported substances).
Make semimonthly deposits & e-file
Superfund chemical taxes require semimonthly EFTPS deposits (by the 14th day after each semimonthly period). EasyFile720 tracks the schedule and e-files your quarterly return.
Two federal excise taxes reinstated by the Infrastructure Investment and Jobs Act effective July 1, 2022, under IRC §§ 4661–4672: a tax on the sale or use of 42 "taxable chemicals" (§ 4661) and a tax on imported "taxable substances" (§ 4671). Both are reported on Form 720 using Form 6627.
The § 4661 tax on taxable chemicals ranges from $0.44 to $9.74 per ton, with a specific rate per chemical listed on Form 6627. The § 4671 tax on imported substances is based on the substance's chemical composition; if the importer does not calculate it and the IRS has not prescribed a rate, the tax is 10% of the appraised value at entry.
For taxable chemicals, the manufacturer, producer, or importer pays the § 4661 tax. For imported taxable substances, the importer pays the § 4671 tax. Both report on Form 720 with Form 6627 attached.
Yes. The Superfund chemical taxes generally require semimonthly EFTPS deposits — due by the 14th day following each semimonthly period — in addition to the quarterly Form 720 filing. EasyFile720 tracks deposit timing for you.
There are 42 taxable chemicals under § 4661 and 151+ imported taxable substances under § 4671 — and the IRS periodically adds substances to the § 4671 list. EasyFile720 reflects the current list; the full schedule is in the Form 6627 instructions.
As reinstated by the Infrastructure Investment and Jobs Act, the taxes apply to sales and uses from July 1, 2022 through December 31, 2031, unless Congress extends them. Returns for periods within that window must report any Superfund liability.
Yes. Section 4662 exempts certain uses — for example methane or butane used as a fuel, and chemicals used to produce fertilizer, animal feed, or qualifying motor fuel. Tax paid on chemicals or substances later exported (or otherwise overpaid) can also be credited or refunded via Schedule C or Form 8849. The Form 6627 instructions list the exempt uses in full.
Every rate and rule on this page comes straight from IRS guidance. Confirm the details yourself:
This page is general information, not tax advice. The Superfund chemical taxes (IRC §§ 4661–4672) carry per-chemical rates and a periodically updated substance list — confirm current rates and the taxable-substance list in the Form 6627 instructions before filing.
IRS Nos. 54 & 17 via Form 6627 — worksheet and deposit schedule handled. Free to get started, pay only when you file.