The Internal Revenue Service (IRS) announced on January 19, 2023, that it received a petition requesting the addition of 4,4′-isopropylidenediphenol-epichlorohydrin copolymer (bisphenol A epoxy resin) to the list of taxable substances under Section 4672(a) of the Internal Revenue Code. 88 Fed. Reg. 3478. The petitioner is Westlake Epoxy Inc., an exporter of 4,4′-isopropylidenediphenol-epichlorohydrin copolymer. According to the petition, “4,4′-Isopropylidenediphenol-Epichlorohydrin Copolymer is a Bisphenol A Epoxy Resin and is used for Epoxide Resin. 4,4′-Isopropylidenediphenol-Epichlorohydrin Copolymer is derived from the taxable chemicals benzene, propylene, chlorine, and sodium hydroxide and produced predominantly from epichlorohydrin and bisphenol-A via a two-step glycidation reaction sequence. Taxable chemicals comprise 92.98 percent of the final product.” Comments and requests for a public hearing are due March 20, 2023. More information on the Superfund excise tax on chemicals is available in our July 13, 2022, memorandum, “Superfund Tax on Chemicals: What You Need to Know to Comply,” and our May 19, 2022, memorandum, “Reinstated Superfund Excise Tax Imposed on Certain Chemical Substances.”