The Natural Resources Defense Council (NRDC) announced on February 11, 2025, that community and environmental groups submitted a petition under Section 21 of the Toxic Substances Control Act (TSCA) to the U.S. Environmental Protection Agency (EPA) to prohibit the use of hydrogen fluoride in domestic oil refining “to eliminate the extreme and unreasonable risks this use presents to public health and the environment.” Brought by NRDC, Clean Air Council (CAC), and Communities for a Better Environment (CBE), the petition states that EPA must issue a TSCA Section 6(a) rule prohibiting the use of hydrogen fluoride in domestic oil refining to eliminate unreasonable risks to public health and the environment. According to the petition, “TSCA requires EPA to issue such a rule because this petition identifies (1) a ‘chemical substance’ ([hydrogen fluoride]) that presents, (2) under one or more ‘conditions of use’ (the use of HF for alkylation at U.S. refineries, and the rail and truck transportation needed to supply HF to those refineries), (3) an unreasonable risk to health or the environment.” The petition notes that hydrogen fluoride can take different forms and that anhydrous hydrogen fluoride tends to form hydrofluoric acid when it mixes with water. As reported in our November 13, 2019, blog item, in 2019, EPA denied a similar TSCA Section 21 petition to prohibit the use of hydrofluoric acid in manufacturing processes at oil refineries. EPA denied the 2019 petition because it lacked the analysis that would be expected in a TSCA risk evaluation preceding a Section 6(a) rulemaking, such as “discussion of the appropriate hazard threshold, exposure estimates, assessment of risks, or how the facts presented allow EPA to comply with its duties under section 26 or other statutory requirements in making an unreasonable risk determination.” Absent such information, EPA “cannot make the threshold determinations necessary to substantively assess and grant a petition for a TSCA section 6(a) rulemaking.”

TSCA requires EPA to grant or deny the petition within 90 days from the day the petition is filed. If EPA grants the petition, EPA must promptly commence an appropriate proceeding. If EPA denies the petition, EPA must publish the reasons for denial in the Federal Register.