Chemical industry groups have urged the IRS to delay implementation of the Superfund taxes on chemicals which were reinstated by Congress in the bipartisan, infrastructure law. According to industry representatives, the IRS has not provided adequate guidance on a range of issues for taxpayers to meet their tax obligations. Specifically, chemical industry representatives have requested that the IRS provide guidance regarding the “taxable substances” that will be subject to the tax, including updating the current list of 151 substances, clarifying the tax rate for each substance, and a process for petitioning for substances to be added to the list. In addition, the industry group is seeking guidance on the series of process concerns, including documentation requirements to claim various credits and refunds and registration requirements.