Superfund Tax on Chemical Substances; Notice of Determinations To Add Substances to List of Taxable Substances

Document Headings Document headings vary by document type but may contain the following: the agency or agencies that issued and signed a document the number of the CFR title and the number of each part the document amends, proposes to amend, or is directly related to the agency docket number / agency internal file number the RIN which identifies each regulatory action listed in the Unified Agenda of Federal Regulatory and Deregulatory Actions See the Document Drafting Handbook for more details. Department of the Treasury Internal Revenue Service AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Notice of determinations. SUMMARY: This notice of determinations modifies the list of taxable substances to include the following two substances: chloro-isobutene-isoprene rubber ((C 4 H 8 ) n -(C 5 H 7.31 Cl 0.69 ) m ; n=97.75, m=2.25) and ethylene-propylene-dicyclopentadiene rubber ((C 2 H 4 ) m -(C 3 H 6 ) n -(C 10 H 12 ) o ; m=73.18, n=26.53, o=0.29). DATES: For purposes of the tax under section 4671 of the Internal Revenue Code (Code) this addition to the list of taxable substances is effective October 1, 2026. For purposes of refund claims under section 4662(e) of the Code, it is effective April 1, 2023. FOR FURTHER INFORMATION CONTACT: Julia Barlow at (202) 317-6855 (not a toll-free number). SUPPLEMENTARY INFORMATION: Background Section 4671(a) of the Code imposes an excise tax on the sale or use of a taxable substance by the importer thereof (section 4671 tax). Section 4672(a)(1) of the Code defines the term taxable substance as any substance which, at the time of sale or use by the importer, is listed as a taxable substance by the Secretary of the Treasury or the Secretary's delegate (Secretary) on the list of taxable substances under section 4672(a) (List). Under section 4672(a)(2), an importer or exporter of any substance may request that the Secretary determine whether such substance should be added to the List as a taxable substance or should be removed f…