# 2026-12868: IRS Adds Two Weird Rubbers to Superfund Tax Hit List

2026-12868, Superfund Tax on Chemical Substances; Notice of Determinations To Add Substances to List of Taxable Substances, is a Federal Register notice from Treasury Department, Internal Revenue Service published 2026-06-26, effective 2026-10-01; PRIA reads it as touching household money (as of 2026-07-03).

- Canonical: https://policyrisk.com/federal-register/2026-12868
- As of: 2026-07-03
- Plain-text twin of the page above; the HTML and this file carry the same facts.

## Facts
- Document number: 2026-12868
- Title: Superfund Tax on Chemical Substances; Notice of Determinations To Add Substances to List of Taxable Substances
- Type: Notice
- Agencies: Treasury Department; Internal Revenue Service
- Citation: 91 FR 38778
- Published: 2026-06-26
- Effective: 2026-10-01
- Comments close: not stated
- Significant: no
- Touches household money: yes
- Regulation identifier numbers: none
- Last updated: 2026-07-03

## In one line

IRS Adds Two Weird Rubbers to Superfund Tax Hit List

## Summary

Starting October 1, 2026, two new rubber substances will be added to the list of chemicals that importers must pay a Superfund tax on. This means companies bringing in chloro-isobutene-isoprene rubber and ethylene-propylene-dicyclopentadiene rubber will have to pay extra fees to help clean up pollution. The tax also applies retroactively for refund claims back to April 1, 2023, so businesses should check their records!

## Abstract

This notice of determinations modifies the list of taxable substances to include the following two substances: chloro-isobutene- isoprene rubber ((C<INF>4</INF>H<INF>8</INF>)<INF>n</INF>- (C<INF>5</INF>H<INF>7.31</INF>Cl<INF>0.69</INF>)<INF>m</INF>; n=97.75, m=2.25) and ethylene-propylene-dicyclopentadiene 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>10</INF>H<INF>12</INF>)<INF>o</INF>; m=73.18, n=26.53, o=0.29).

## Effects PRIA read

- Tax on Chloro‑Isobutene‑Isoprene Rubber: cost, medium. If your business imports chloro‑isobutene‑isoprene rubber, an excise tax will apply starting October 1, 2026. The Secretary prescribed a tax rate of $9.46 per ton for this substance (determination made June 25, 2026), and the rule is effective for refund claims back to April 1, 2023.
- Tax on Ethylene‑Propylene‑Dicyclopentadiene Rubber: cost, medium. If your business imports ethylene‑propylene‑dicyclopentadiene rubber, an excise tax will apply starting October 1, 2026. The Secretary prescribed a tax rate of $9.64 per ton for this substance (determination made June 25, 2026), and the rule is effective for refund claims back to April 1, 2023.

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- [2026-20026](https://policyrisk.com/federal-register/2026-20026): Trump Accounts, 2026-09-30
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- [2026-18219](https://policyrisk.com/federal-register/2026-18219): Car Loan Interest Deduction, 2026-09-08
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## Sources
- [2026-12868 on federalregister.gov](https://www.federalregister.gov/documents/2026/06/26/2026-12868/superfund-tax-on-chemical-substances-notice-of-determinations-to-add-substances-to-list-of-taxable)
- [2026-12868 as published (PDF)](https://www.govinfo.gov/content/pkg/FR-2026-06-26/pdf/2026-12868.pdf)

## Related
- [Previous: 2026-12867, Submission for OMB Review; Comment Request](https://policyrisk.com/federal-register/2026-12867)
- [Next: 2026-12869, Agency Information Collection Activities; Extension, Without Change, of a Curre…](https://policyrisk.com/federal-register/2026-12869)
- [All Federal Register documents](https://policyrisk.com/federal-register)

Source: PRIA, https://policyrisk.com/federal-register/2026-12868 (as of 2026-07-03).