Reconsideration of the 2020 National Emission Standards for Hazardous Air Pollutants: Miscellaneous Organic Chemical Manufacturing Residual Risk and Technology Review

On August 12, 2020, the U.S. Environmental Protection Agency (EPA) published the final risk and technology review (RTR) for the Miscellaneous Organic Chemical Manufacturing NESHAP (2020 MON final rule) pursuant to Clean Air Act (CAA). Subsequently, the EPA received and granted petitions for reconsideration on two issues, specifically, on the use of the EPA's IRIS value for ethylene oxide in assessing cancer risk for the source category, and the use of the Texas Commission on Environmental Quality's (TCEQ's) risk value for ethylene oxide as an alternative risk value to the EPA's IRIS value for purposes of evaluating risk as part of the CAA residual risk review. On February 4, 2022, the EPA proposed the Reconsideration of the 2020 National Emission Standards for Hazardous Air Pollutants (NESHAP): Miscellaneous Organic Chemical Manufacturing Residual Risk and Technology Review to address these two issues and request public comment. This action finalizes the EPA's decision to use the IRIS value for ethylene oxide in the risk assessment for the 2020 MON final rule and our decision to reject the use of the TCEQ's risk value for ethylene oxide as an alternative risk value to the EPA's IRIS value. As such, in this final action, EPA is making no changes to the risk assessment or related regulatory text for the miscellaneous organic chemical manufacturing source category.