Superfund & Environmental Excise Taxes

The federal government taxes petroleum, hazardous chemicals, ozone-depleting substances, and certain imported goods under Chapter 38 of the tax code — a set of excise taxes that fund the Superfund environmental cleanup program and discourage use of ozone-depleting refrigerants and other harmful substances. These taxes operate entirely outside everyday consumer awareness but are embedded in the cost of gasoline, plastics, solvents, refrigerants, and countless industrial products. After a 26-year lapse, Congress reinstated the Superfund chemical excise taxes in 2022 as part of the Inflation Reduction Act — a significant policy reversal that brought back rates not seen since 1995, and in some cases raised them. The excise revenue funds EPA's Superfund hazardous waste cleanup program.

Current Law (2026)

Legal Authority

• 26 U.S.C. § 4611 — Tax on petroleum: imposed on crude oil received at a U.S. refinery and on petroleum products entered for consumption, use, or warehousing; also on domestic crude oil used or exported without prior refinery processing
• 26 U.S.C. § 4612 — Petroleum tax definitions: "crude oil" includes condensates and natural gasoline; "domestic crude oil" means oil from a U.S. well; "United States" includes 50 states, DC, Puerto Rico, and possessions
• 26 U.S.C. § 4661 — Tax on taxable chemicals: per-ton rates on 42 specific chemicals sold by manufacturers, producers, or importers; rates set by statutory table (not adjusted for inflation)
• 26 U.S.C. § 4662 — Chemical tax definitions and special rules: "taxable chemical" means any substance on the § 4661(b) list that is manufactured in or entered into the U.S.; exemptions for certain exports, uses as fuels, and qualifying recycling activities
• 26 U.S.C. § 4671 — Tax on imported substances: closes the loophole that would allow manufacturers to avoid § 4661 by importing the finished product rather than the taxable chemicals; rate equals what the chemicals in the product would have owed under § 4661
• 26 U.S.C. § 4672 — Imported substance definitions: a substance qualifies as "taxable" if it's on the Secretary's list or if the Secretary determines it's derived from listed chemicals at more than 50% of its weight
• 26 U.S.C. § 4681 — Tax on ozone-depleting chemicals (ODCs): rate equals a base tax amount multiplied by the substance's ozone-depletion factor; more harmful substances (like CFC-11) carry proportionally higher tax
• 26 U.S.C. § 4682 — ODC definitions: "ozone-depleting chemical" means any substance listed in the statutory table at the time of sale; includes both domestically produced and imported ODCs

How These Taxes Work

The petroleum tax (currently $0.164/barrel after the IRA 2022 increase from the pre-IRA $0.097 rate) hits crude oil at the refinery gate or at import. It's a per-barrel flat rate, so the revenue it generates is directly proportional to U.S. oil throughput. A large refinery processing 300,000 barrels per day pays roughly $18 million in this tax annually. Proceeds go into the Hazardous Substance Superfund to pay for EPA cleanup of contaminated sites where no responsible party can be identified or compelled to clean up.

The chemical excise taxes (§ 4661) apply to 42 specific chemicals at per-ton rates set by statute. These chemicals — including benzene, ethylene, propylene, methane, and many others — are precursors to plastics, fertilizers, pharmaceuticals, and countless industrial products. A manufacturer of polyethylene made from ethylene ($9.74/ton) effectively pays the tax upstream when it buys ethylene feedstock, which is embedded in the cost of the final plastic. After lapsing in 1995, these taxes were reinstated by the Inflation Reduction Act at roughly double the prior rates.

The imported substances tax (§ 4671) was designed to prevent competitive distortion: without it, a foreign manufacturer could import the finished plastic or chemical product free of excise tax while a domestic manufacturer paid tax on its ethylene inputs. The § 4671 tax neutralizes this by applying an equivalent tax to the imported finished good.

Ozone-depleting chemical taxes (§ 4681) operate on a multiplier system keyed to each chemical's scientifically measured harm to the stratospheric ozone layer. CFC-11, one of the most ozone-destructive refrigerants, carries the highest effective rate. This tax structure was part of the U.S. implementation of the Montreal Protocol obligations and has largely accomplished its goal: ODC production in the U.S. has dropped dramatically, and the tax is now a minor revenue item covering mostly residual uses.

How It Affects You

If you operate a petroleum refinery or oil import terminal: The $0.164/barrel petroleum excise tax (raised by the IRA from $0.097) is a direct cost that attaches when crude oil is received at a U.S. refinery or when petroleum products are imported for consumption. A refinery processing 200,000 barrels per day incurs roughly $12 million per year in petroleum excise. The tax is paid on IRS Form 720 quarterly, with semi-monthly deposits required for larger facilities. Since the tax attaches at the refinery rather than the pump, it's embedded invisibly in the wholesale price of refined products — gasoline, diesel, jet fuel, heating oil — and ultimately passed through to every commercial and retail purchaser. If you're managing refinery operating costs, this tax has been a constant cost component since SARA 1986 and is unlikely to be repealed given its dedicated Superfund funding purpose.

If you manufacture or import chemical products subject to § 4661 or § 4671: The 42-chemical list in § 4661 covers most basic petrochemical feedstocks — benzene, ethylene, propylene, butane, acetylene, methane, chlorine, and others. If your facility is the manufacturer or importer of these substances, you are the taxpayer: you file and pay on Form 720 and include the excise in your product pricing. If you're a downstream buyer of taxable chemicals (a plastics converter, a pharmaceutical intermediary manufacturer, a fertilizer blender), the excise is passed through in your input cost rather than assessed directly to you. The reinstatement in January 2023 after a 26-year lapse means compliance infrastructure — tracking which purchases trigger which rates, maintaining records for IRS audit — had to be rebuilt from scratch. IRS Notice 2021-66 and subsequent guidance set out the compliance framework; the current IRS published list of taxable imported substances is essential for any importer of chemical-derived products. Verify your substance classifications against the current IRS list at irs.gov/businesses/small-businesses-self-employed/excise-tax before each filing period.

If you service or maintain older refrigeration or air conditioning equipment: Ozone-depleting refrigerants like R-22 (HCFC-22) were phased down under the Clean Air Act and largely discontinued in new equipment after 2010 and new production after 2020. Equipment manufactured before 2010 may still operate on R-22 or other ODCs and will require service refrigerant as long as it operates. The ODC excise tax contributes to the high and rising cost of R-22 service refrigerant — in 2024, R-22 was selling for $30–$50+ per pound at wholesale, compared to under $5 per pound before the phase-down. If you manage a large portfolio of older commercial HVAC equipment (building management, property management, manufacturing facilities), quantify your refrigerant service costs and model replacement with modern HFC or HFO equipment — the economics of equipment replacement often close faster than they appear once R-22 service costs are projected forward.

If you're near a Superfund site: The petroleum and chemical excise taxes fund the Hazardous Substance Superfund — the dedicated account EPA uses to clean up contaminated sites where the responsible parties can't be found or compelled to clean up. If you live or work near one of the approximately 1,300 National Priorities List (NPL) sites, your cleanup is partly funded by these taxes. EPA's Superfund site information, including cleanup status, contaminants found, and health risk assessments, is publicly searchable at epa.gov/superfund. If you're concerned about a site in your community, CERCLA requires EPA to create a Community Involvement Plan and hold community information sessions — contact your EPA regional office through the site's web page to ask about cleanup timelines and community health protections.

State Variations

States generally do not have equivalent Superfund excise structures, though many states have their own hazardous substance taxes that fund state-level cleanup programs. The federal excise applies nationally regardless of state.

Implementing Regulations

The Superfund excise taxes are implemented under 26 CFR Part 52 — Environmental Tax Regulations. Part 52 is the IRS's rule implementing chapter 38 of the Internal Revenue Code (26 U.S.C. §§ 4661–4682). Key provisions:

• § 52.0-1 — Introduction: the regulations govern "environmental taxes" imposed by IRC chapter 38, which includes the petroleum excise (§ 4611), the chemical excise (§ 4661), the imported substances tax (§ 4671), and the ozone-depleting chemical taxes (§ 4681–4682); procedural requirements for returns, deposits, and payments are in 26 CFR Part 40
• § 52.4681-1 — Taxes on ozone-depleting chemicals (ODCs): IRS regulations implement the ODC tax framework, including identification of taxable ODCs, their ozone-depletion potentials (ODP), and the calculation of the tax based on ODP multiplied by the base rate; exemptions for ODCs used in medical devices (metered-dose inhalers), ODC exports, and ODCs used in processes that destroy the chemical before release are specified; the IRS has published guidance on which substitute refrigerants are ODCs for tax purposes as new HFC and HFO compounds have been introduced
• § 52.4682-1 — Definitions for ODC tax: "ozone-depleting chemical" means any substance listed in 26 U.S.C. § 4682(a) — including CFCs, halons, carbon tetrachloride, methyl chloroform, and HCFCs; the regulations define "importer" for ODC purposes to address materials imported for use in refrigeration systems, aerosol propellants, and industrial applications
• § 52.4682-2 — ODC tax exemption for exports: ODCs exported from the United States are not taxed; the exporter must demonstrate that the ODC was not used in the United States before export; the regulations specify documentation requirements
• § 52.4682-3 — ODC tax on imported products containing ODCs: products imported that contain or were manufactured using ODCs (e.g., foam insulation blown with CFCs) are subject to an equivalent tax to prevent competitive distortion — the same principle as the § 4671 imported substances tax for petroleum and chemical excises

Part 52 governs only the ozone-depleting chemical taxes (§§ 4681–4682). The petroleum excise (§ 4611) and chemical excise (§ 4661) have their own regulatory guidance primarily in IRS publications, revenue procedures, and notices rather than formal CFR Part 52 regulations — the IRS issued extensive guidance in Notice 2021-66 and related notices after the IRA 2022 reinstatement of the §§ 4661–4671 taxes, which lacked formal regulation because they had been dormant since 1995. As of 2026, IRS has not yet finalized new CFR regulations implementing the reinstated chemical excise taxes, relying on pre-1995 regulatory text and post-IRA guidance documents.

Pending Legislation

No major pending legislation as of April 2026. The IRA reinstatement of the chemical excise taxes was a significant legislative development in 2022; rates are now set by statute and would require Congressional action to change.

Recent Developments

• IRA 2022 reinstated the chemical excise taxes after 26 years: The original Superfund chemical excise taxes lapsed in 1995 when the Superfund taxing authority expired and Congress did not renew it. The Hazardous Substance Superfund was left to rely on general appropriations rather than dedicated excise revenue. The Inflation Reduction Act of 2022 reinstated the § 4661 chemical taxes effective January 1, 2023, at roughly double the pre-1995 rates. IRS issued Notice 2021-66 (setting out initial guidance) and subsequent revenue procedures explaining which substances are covered, how importers calculate the § 4671 imported-substance tax, and how to report and pay the reinstated taxes on Form 720. The 26-year gap meant most tax and compliance professionals had never dealt with these taxes before.
• Imported substances list and IRS determination process: After the 2022 reinstatement, many importers discovered they weren't sure whether their products were subject to § 4671. IRS published an initial list of taxable imported substances and established a process for importers to request a determination about unlisted substances. IRS has continued to update the list as requests come in; importers of chemical-derived products should verify their classification against the current published list rather than relying on the pre-1995 list.
• Compliance and administrative challenges: Because the taxes were dormant for 26 years, reinstatement created significant implementation friction. Supply chain accounting systems weren't set up to track which inputs were taxable chemicals. Contract terms between chemical manufacturers and downstream buyers often didn't address who bears the excise cost. IRS enforcement posture in the first years has been focused on education and guidance rather than aggressive audits, but penalties for underpayment of excise taxes are real.
• Petroleum tax rate and Superfund funding levels: The $0.164/barrel petroleum tax (raised from $0.097 by the IRA, effective 2023) generates roughly $2–2.5 billion annually for the Hazardous Substance Superfund, depending on U.S. oil throughput. Combined with the reinstated chemical taxes and general appropriations, Superfund funding has increased since 2023. EPA has used expanded resources to accelerate work on the National Priorities List — the approximately 1,300 Superfund sites requiring long-term remediation — and to fund emergency response actions at new contamination sites. The adequacy of Superfund resources relative to the cleanup backlog remains a persistent policy concern.
• PFAS hazardous substance designation survives into 2025: The Biden EPA designated perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) as CERCLA hazardous substances in April 2024 — a landmark rule that extended Superfund cleanup authority to PFAS-contaminated sites for the first time. The Trump administration reviewed but did not reverse the PFAS hazardous substance designation as of April 2026, though EPA enforcement posture toward liable parties (including municipal water utilities facing unexpected PFAS liability) has been more lenient. Manufacturers of PFAS chemicals — 3M, DuPont/Chemours — have settled billions in PFAS litigation but CERCLA cleanup cost allocation remains contested.
• Trump EPA budget cuts and Superfund pace: The Trump administration's EPA budget proposals for FY2026 included significant cuts to Superfund remediation programs. DOGE-driven workforce reductions at EPA's Office of Land and Emergency Management — which manages Superfund cleanups — have slowed site assessment and remediation actions. Industry groups applauded reduced enforcement pressure; environmental advocates and communities near contaminated sites argue that slower cleanup pace harms public health. The Superfund excise taxes remain in effect and continue generating revenue regardless of EPA spending levels.