Federal law generally sets a floor, rather than a ceiling, when it comes to emission reduction regulations, and thus, when assessing a facility’s compliance and legal risks it is important to track state and local laws, regulations, and enforcement activities. This is particularly important for EtO, where several states have gotten ahead of EPA in setting state specific EtO risk thresholds and regulatory requirements.

As noted in our prior alert, public attention was drawn to EtO with the publication of the 2014 NATA in 2018, which identified many census tracts throughout the nation that merited further analysis for potential cancer risk associated with estimated EtO emissions. Because the existing federal NESHAP standards for industrial sources of EtO were all based on EtO unit risk estimates from before the 2016 IRIS EtO URE, and because EPA did not immediately propose to revise federal NESHAPs in light of the 2016 IRIS EtO URE and the 2014 NATA, many states have felt pressure to impose additional regulations on top of federal regulations. But in the absence of guidance from EPA on the meaning of the IRIS EtO URE and how to use it in the regulatory context (rather than in the preliminary risk screening context it was developed for), the result has been a complicated and contradictory patchwork of regulations that vary from state to state. Three basic approaches have emerged.

  1. After the publication of the 2014 NATA in 2018, a handful of states adopted the IRIS EtO URE itself as a basis for determining community risks and permitting obligations. Most notably, Illinois, Michigan and, curiously enough, Georgia, immediately started using EPA’s screening value to calculate community risk associated with every industrial EtO emitter they could locate. These states then initiated administrative enforcement actions based on the resultant perceived health risks, required additional emission controls, and even required air permits for small sources that previously were considered de minimis emission sources. These aggressive inquiries and enforcement actions were taken whether or not the facilities were otherwise subject to permitting, and whether or not the facilities were in compliance with their existing air permits. All three states ordered at least one medical device sterilizer to shut down operations on temporary or indefinite bases, and required other sterilizers and chemical manufacturers to either shut down or spend eight-digit sums of money on additional emission controls. In January of this year, New York also issued a regulatory proposal to adopt the IRIS EtO URE as its risk value for EtO, but as of this writing, does not yet appear to be using it as a basis for enforcement and permitting actions. Also in January of this year, New Mexico filed a lawsuit against a medical sterilizer emitting EtO alleging that their level of EtO emissions imposed a public nuisance based on the IRIS EtO URE even if the facility complied with its federal air emission permit; a hearing was held on May 26 on New Mexico’s request for an injunction to temporarily shut down the facility, with no order issued as of this date.
  2. Some other states, including California, North Carolina, South Carolina and Texas, have published their own state-specific risk estimates for EtO for purposes of evaluating community risk. The range of these state-specific standards further illustrate the scientific debate in this area over both the toxicology of EtO, and acceptable risk parameters. While California’s long-term exposure risk for EtO is actually somewhat lower than the IRIS EtO URE (but is only directly applicable to permitting of new and modified facilities), North Carolina’s is about 100 times the IRIS EtO URE, and Texas adopted a regulatory risk threshold for EtO that is about 1,000 times higher than the IRIS EtO URE, based on a peer-reviewed study of EtO risk published in 2020 by the Texas Commission of Environmental Quality (TCEQ). South Carolina takes a somewhat different approach, evaluating community exposures to EtO with a 24-hour exposure risk value based on OSHA exposure limits rather than based on any long-term lifetime exposure risk factor.
  3. Many other states (e.g., Alabama, Tennessee and Florida) are simply continuing to enforce existing federal standards for industrial sources of EtO, without imposing their own additional limits based on the IRIS EtO URE or any other long-term exposure risk calculus for EtO, ostensibly opting to wait until EPA has determined any necessary and appropriate regulatory adjustments.