EPA to Reconsider Issues Related to Risks Posed by Ethylene Oxide Emissions for Certain Types of Chemical Manufacturing
WASHINGTON (Jan. 26, 2022) – The U.S. Environmental Protection Agency (EPA) is proposing to reconsider the August 2020 National Emission Standards for Hazardous Air Pollutants (NESHAP) for chemical plants that fall under the Miscellaneous Organic Chemical Manufacturing source category (“2020 MON final rule”). EPA is proposing to continue to rely on the agency’s 2016 peer-reviewed value to represent the toxicity of ethylene oxide when assessing risk from the manufacture of miscellaneous specialty organic chemicals in the 2020 MON final rule. EPA’s peer-reviewed value showed that ethylene oxide was significantly more toxic than previously understood.
The agency is proposing this action because the 2016 ethylene oxide Integrated Risk Information System (IRIS) assessment remains the best available science. In addition, EPA is proposing to decline to use the Texas Commission on Environmental Quality’s (TCEQ) risk value for ethylene oxide instead of the EPA’s 2016 value.
“People living near chemical plants are increasingly concerned about exposure to ethylene oxide, and the science shows it is a potent air toxic posing serious health risks,” said EPA Administrator Michael S. Regan. “Today we reinforce and advance EPA’s commitment to protect overburdened communities by following the best available science and data. Under my watch, I will do everything I can to listen to folks that are hurting and to take action to protect them.”
In response to the 2020 MON final rule, the Administrator received and granted petitions for reconsideration on two issues, specifically, on (1) the use of EPA’s 2016 IRIS unit risk estimate (URE) for ethylene oxide in assessing cancer risk for the source category, and (2) the use of the TCEQ risk value for ethylene oxide as an alternative risk value to EPA’s 2016 IRIS value for purposes of evaluating risk under the Clean Air Act.
In this reconsideration action, EPA is addressing these two issues and is proposing the following:
- To not change its decision to use EPA’s 2016 IRIS value for ethylene oxide when assessing risk for the source category in the 2020 MON final rule, as the 2016 ethylene oxide IRIS assessment remains the best available science;
- To decline to use the TCEQ risk value for ethylene oxide instead of the EPA’s 2016 IRIS value, after careful consideration of the TCEQ risk value for ethylene oxide.
As such, EPA is not proposing any changes to our risk assessment for the 2020 MON final rule. EPA will accept comment on the two issues addressed in this reconsideration action for 45 days after publication in the Federal Register. EPA is seeking comment only on the two identified petition issues.
EPA is moving ahead with actions under the Clean Air Act that will address air emissions of ethylene oxide. The agency is currently undertaking a review of a rule for commercial sterilizers, which will consider risk, and expects to issue a proposal in 2022. EPA intends to use the 2016 IRIS value in the upcoming proposed rule for sterilizers. The agency has been collecting information about the source category, including Information Collection Requests (ICR) under the Clean Air Act. The deadline for commercial sterilizers to submit their most recent ICR response was November 2021. EPA is evaluating that data now.