Biden’s 11th-Hour Ethylene Oxide Decision Continues the Environmental Protection Agency’s Expansion Into Occupational Safety

At a Glance

• Use of ethylene oxide (EtO) is the most common method of terminal sterilization of medical devices in the United States, used to sterilize more than 20 billion devices sold each year. Most importantly, approximately one-third of health care facilities, including hospitals, veterinary clinics and dentists, use EtO on-site to sterilize medical devices and equipment. These facilities may need additional ventilation and abatement devices, and respirators may be required. Health care facilities will likely need monitoring to ensure they are below the 0.1 ppm threshold. 
• The decision phases out the use of EtO for other applications, including museum, library and archival materials; cosmetics; musical instruments; and beekeeping equipment. EtO is also used to fumigate and sterilize spices, dried herbs, processed vegetables, and other seasoning materials to reduce pathogens. 
• This interim decision is a bold step by EPA, but its long-term impact remains uncertain as it awaits further review and potential changes under the new administration. Even if the decision is rescinded, affected industries will have to grapple with its far-reaching recommendations for occupational safety. 

On January 14, 2025, the Biden administration’s U.S. Environmental Protection Agency (EPA) posted a last-minute “interim” decision in the Federal Register for its review of ethylene oxide (EtO) under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). This decision was the final action among several by the Biden administration’s EPA to address EtO emissions, following a re-assessment in 2016 by the Obama administration that reclassified ethylene oxide from a “probable” carcinogen (1985) to a “carcinogen” based on updated epidemiological studies and animal data. Given the timing, the Biden administration likely hastened to issue this interim decision before the transition to the Trump administration, which previously called into question EPA’s revised determination of EtO as a human carcinogen.

EPA first approved ethylene oxide as a sterilizer in 1966, mostly for fumigating medical devices. According to the U.S. Food & Drug Administration, EtO is the most common method of terminal sterilization of medical devices in the United States, used to sterilize more than 20 billion devices sold in the U.S. each year — i.e., 50% of all devices requiring sterilization. As many learned during the COVID-19 pandemic, antimicrobial chemicals such as EtO are subject to EPA registration, approval and regulation under FIFRA. Despite its prevalent use, there is currently only one supplier of EtO and less than 200 registered commercial sterilizers in the United States. However, this number is expected to decrease due to EPA rulemaking and numerous personal injury lawsuits filed after the 2016 redesignation.

What Is EPA’s Authority to Regulate EtO Under FIFRA?

Under FIFRA, EPA regulates a host of activities involving registered pesticides like EtO to protect human health and the environment, including: how and where pesticides are manufactured, pesticide labeling and directions for use, and allowable marketing claims concerning the advertising and sale of registered pesticides. Pesticide registrations are also subject to continuous review, typically every 15 years, to ensure they meet evolving standards in scientific knowledge, policies and practices. 

The EPA began the process of updating EtO’s pesticide registration in 2013. However, because additional information is needed to complete a registration review — specifically data on worker exposure and monitoring technologies — the EPA issued this “interim” decision to implement immediate risk mitigation measures deemed necessary to protect human health and the environment while additional data is collected.

What Does EPA’s Interim Decision Require?

In issuing this decision, EPA claims broad authority to regulate the use of EtO, even though this likely encroaches on the jurisdiction of other federal agencies such as OSHA. Notably, the most significant part of this decision is its attempt to reduce OSHA’s permissible exposure limit (PEL) for workers from 1 ppm (8-hour time-weighted average) to 0.1 ppm.

According to EPA, this action is warranted because most of OSHA’s PELs have not been updated since their establishment in 1971 due to OSHA’s limited authority to do so. EPA does not have this limitation. Therefore, EPA asserts that it can develop risk mitigation measures to address risks from the pesticide uses of chemicals that OSHA regulates, despite potential divergence from OSHA’s standards.

In addition to establishing an “EPA Occupational Exposure Limit,” the decision also identifies monitoring, training and mitigation requirements for workplaces using EtO, traditionally considered the purview of OSHA.

Impacts Reach Far Beyond Commercial Sterilizer Use 

However, EtO is used beyond commercial sterilizers. The decision phases out the use of EtO for several applications, including museum, library and archival materials; cosmetics; musical instruments; and beekeeping equipment. EtO is also used to fumigate and sterilize spices, dried herbs, processed vegetables, and other seasoning materials to reduce pathogens. Most importantly, approximately one-third of health care facilities, including hospitals, veterinary clinics and dentists, use EtO on-site to sterilize medical devices and equipment. Indeed, the EPA cites the case of a hospital worker diagnosed with leukemia soon after employment as support for this decision. These facilities may need additional ventilation and abatement devices, and respirators may be required. Health care facilities will likely need monitoring to ensure they are below the 0.1 ppm threshold.

Next Steps

The first step following this announcement is for EtO manufacturers to submit label amendments within 60 days for EPA’s review and approval. Once approved, the EPA will gather additional data to reach a final decision, which is expected “within 8 years.” Specifically, EPA is looking to collect data on potential exposures in warehouses downstream of the EtO treatment process that may be exposed to EtO off-gassing from the treated items. The implementation and interpretation of this interim decision will either be left to the incoming Trump administration, which could potentially loosen or reverse the exposure limits and mitigation measures based on new data. If no changes are made, then issuing the final decision will be left to future administrations. 

Conclusion

This interim decision is a bold step by EPA, but its long-term impact remains uncertain as it awaits further review and potential changes under the new administration. Even if the decision is appealed, affected industries will have to grapple with its far-reaching recommendations for occupational safety.