Ethylene Oxide

EPA's new second risk review process commits the agency to review other air toxics following the same process it used to develop its IRIS value for EO. Yet, ...

As outlined in our earlier alerts since releasing the EO IRIS value in 2016, EPA has failed to respond meaningfully to questions about the flaws in its methodology and data selection — even though it has relied upon that IRIS value in rulemaking and other Agency initiatives. Second, notwithstanding its flaws, EPA and others have treated the 2016 EO IRIS value as settled science, with far-reaching repercussions for industry. Importantly, EPA’s emphasis on these 23 facilities is the product of an information collection request (ICR) made in 2021 to commercial sterilizers to inform EPA’s risk assessment in areas near approximately 100 commercial sterilizers. Members of the scientific community, industry, and several states claim the IRIS value is wrong and unsupported by the best science. Presumably, at that point, EPA’s IRIS value can be finally vetted – but the damage to industry may well have been done, and the fears surrounding EO may be permanently ensconced in the public domain. EPA then points to its core guiding principle that it ensures that “we use the most up-to-date toxicity information available for all hazardous air pollutants (HAP) regulated under the Clean Air Act (CAA).” See June 1 EPA Memo. But notably absent from this secondary risk review process is participation by state and industry stakeholders, any entity outside the Agency, or even its own Scientific Advisory Board. Moreover, the process precludes judicial challenge at the time a risk review is undertaken, or the IRIS value is published – stakeholders must wait until EPA has “used” that value in a final agency action. Companies that manufacture or use priority constituents on EPA’s IRIS list should closely monitor developments and utilize the few available public participation opportunities to ensure that the administrative record reflects the full body of scientific literature and data. EPA’s new second risk review process commits the agency to review other air toxics following the same process it used to develop its IRIS value for EO. Yet, that process lacks any requirement for the Agency to consider input from stakeholders other than those within the Agency itself. Moreover, the science about the risks of EO is far from settled and new developments continue to unfold. The U.S. Environmental Protection Agency’s (EPA) commitment to its controversial Integrated Risk Information System (IRIS) value for Ethylene Oxide (EO) remains unwavering as two recent developments reflect. But an IRIS value itself has influence and substantial consequences well before the appeal of a final agency action becomes ripe.