On June 1, 2020, the U.S. Environmental Protection Agency (EPA) announced final action to reduce emissions of ethylene oxide (EO) from certain sources. EO is an intermediary chemical used to make plastics, textiles and antifreeze, and also is used to sterilize medical devices. Scrutiny of EO has increased in the past few years due to the chemical’s potential carcinogenic effects. EPA’s regulatory action is the first update to national hazardous air pollutant limits for the chemical manufacturing sector since 2006, and the agency expects the regulations to reduce EO emissions by 0.76 tons per year. The announcement caps off a flurry of recent activity by EPA and state agencies aimed at addressing EO emissions.

EPA’s regulatory action

The 1990 Clean Air Act Amendments list EO as a hazardous air pollutant, and EPA identified EO as a human carcinogen and updated the chemical’s risk value in 2016. Focus on EO grew in 2018 when EPA released its National Air Toxics Assessment. The assessment found that EO emissions may contribute to potentially elevated cancer risks in certain communities around the country. EPA therefore developed a two-pronged approach for evaluating EO emissions. One prong involves reviewing existing regulations for facilities that emit EO. The other prong involves collecting additional information to identify potential opportunities for reducing EO emissions.

The EO emissions reductions announced by EPA on June 1 are part of a larger rulemaking package that amends the Miscellaneous Organic Chemical Manufacturing National Emission Standards for Hazardous Air Pollutants (MON). As required by the Clean Air Act, EPA must review and revise the emissions standards for MON sources every eight years. EPA’s evaluation during the review period identified EO emissions as the main driver of unacceptable health risk associated with MON sources. Therefore, the MON rulemaking targets EO emissions from storage tanks, process vents, and equipment leaks. The rulemaking also establishes additional monitoring and operational requirements for flares that control EO emissions. A pre-publication version of the MON rule indicates that it will take effect on the date of publication in the Federal Register. An appeal period for review of the rule in the U.S. Court of Appeals for the D.C. Circuit will last for 60 days from the date of publication.

Regulation of EO by other federal agencies

 EPA is not the only federal agency that regulates EO. The U.S. Occupational Safety and Health Administration (OSHA) recognizes EO as a potential carcinogen and developed a standard to regulate workplace exposure to the chemical. OSHA’s standard requires air monitoring, controls, personal protective equipment (PPE), and hazard communication for EO. OSHA also established a permissible exposure limit for EO that places a regulatory limit on the permissible concentration of the chemical in air in regulated workplaces (1 ppm as an 8-hour time weighted average; 5 ppm as an excursion limit averaged over a period of 15 minutes). These regulations seek to mitigate the potential for worker exposures to EO.

U.S. Food and Drug Administration (FDA) regulations also address EO. FDA regulates medical devices, and EO is commonly used to sterilize medical devices. As part of its pre-market review of sterilized medical devices, FDA evaluates whether the sterilization process aligns with industry standards. This includes a review of processes aimed at limiting residual EO on sterilized medical devices. Additionally, FDA recently announced efforts to facilitate reductions in overall EO use at medical sterilization plants.

State action

Several states are also taking a close look at EO. In May, the Texas Commission on Environmental Quality (TCEQ) finalized its updated safe exposure level for ethylene oxide. TCEQ’s new long-term effects screening level for EO is 2.4 parts per billion. This value is now the health-protective air concentration that will be used to determine limits for proposed air permits in Texas. The state’s previous effects screening level for EO was 1 part per billion. According to a recent study it conducted, however, TCEQ determined that the updated effects screening level remains protective for people living near facilities that emit EO while providing flexibility for the medical sterilization industry particularly given the COVID-19 pandemic.

Illinois has taken a different approach with EO. In May 2019, the Illinois General Assembly passed two bills addressing sources of EO emissions. The legislation imposed some of the strictest limits in the nation on EO emissions from sterilization facilities and other facilities that use EO. This state action coincided with the shutdown of a medical device sterilization facility outside Chicago. The facility came under scrutiny by local residents in 2018 after EPA’s National Air Toxics Assessment identified areas surrounding the facility as presenting excessive cancer risk. Ultimately, the facility decided to cease operations in September 2019 due to community backlash and regulatory hurdles.

Georgia has also focused attention on medical device sterilization facilities utilizing EO. This attention followed EPA’s National Air Toxics Assessment, which identified areas around certain medical device sterilization facilities in Georgia as posing potentially elevated cancer risk due to EO. As a result, Georgia began to work with those facilities to implement voluntary improvements to better control EO in the summer of 2019. Georgia’s efforts continued in December 2019 when it issued a notice of violation requiring a warehouse storing medical equipment sterilized with EO to obtain an air permit and monitor and control EO emissions. Separately, warehouse workers in Georgia filed a lawsuit in May 2020 seeking to recover damages associated with alleged exposure to unsafe levels of EO.

More to come

All of this activity indicates that EO issues will remain a regulatory focus. In fact, attention on EO seems likely to grow given the importance of sterilized medical equipment during the COVID-19 pandemic. Additionally, EPA is working on a rulemaking for EO commercial sterilization and fumigation operations and recently proposed an information request to gather emissions data from several facilities. Commercial sterilization companies and chemical manufacturers should track federal EO developments closely for potential impacts to their business. They should also pay close attention to state and local actions as efforts at those levels have proven effective for addressing EO emissions and exposure in some communities.