Superfund Tax on Chemical Substances; Request To Modify List of Taxable Substances; Notice of Filing for Styrene Isoprene Block Copolymer; x+z=482, y=2,178.51, a=1.70

Treasury asked for input on modifying the list of taxable chemical substances under the Superfund chemical tax — a niche tax list with real plant-gate cost.

Adding or dropping a chemical from the taxable-substance list changes excise exposure for manufacturers and importers who thought their product was settled.

Filing abstract (agency text): This notice of filing announces that a petition has been filed requesting that styrene isoprene block copolymer ((C<INF>8</INF>H<INF>8</INF>)<INF>x</INF>- (C<INF>5</INF>H<INF>8</INF>)<INF>y</INF>- (C<INF>8</INF>H<INF>8</INF>)<INF>z</INF>- (C<INF>33</INF>H<INF>56</INF>N<INF>4</INF>OS<INF>2</INF>)<INF>a</INF>; x+z=482,…

Chemical manufacturers, customs brokers, and tax directors: review the requested modification and the comment path before you reprice an SKU.

Federal Register filing: https://www.federalregister.gov/documents/2026/10/01/2026-20061/superfund-tax-on-chemical-substances-request-to-modify-list-of-taxable-substances-notice-of-filing

This is a Notice Nearby publisher-desk Federal brief — a short in-house summary of a public federal filing. It is not official agency minutes, not a newspaper story, and not Legal Publication. It does not satisfy a statutory notice requirement.