The Internal Revenue Service (IRS) announced on December 28, 2022, that it received a petition requesting the addition of polyoxymethylene to the list of taxable substances under Section 4672(a) of the Internal Revenue Code. 87 Fed. Reg. 79938. The petitioner is Celanese Ltd., an exporter of polyoxymethylene. According to the petition, “polyoxymethylene is an engineering thermoplastic used in precision parts requiring high stiffness, low friction, and excellent dimensional stability. It is widely used in the automotive and consumer electronics industry as well as many other high-performance uses.” Polyoxymethylene is made from methane and is manufactured through the polymerization of formaldehyde, and taxable chemicals constitute 50.0 percent by weight of the materials used to produce it. Comments and requests for a public hearing are due February 27, 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.”