The U.S. Environmental Protection Agency (EPA) has finalized its Interim Decision on Ethylene Oxide (EtO), a widely used pesticide and sterilizing agent. EPA announced stronger protections to reduce cancer risk for workers and communities. EtO is used to sterilize approximately 50% of U.S. medical devices and 30% of dried herbs and spices. 

Health Risks of Ethylene Oxide 

EtO is a known human carcinogen, linked to lymphocytic leukemia, breast cancer, non-Hodgkin lymphoma, and myeloma. Workers at sterilization facilities and individuals living or working near these facilities are at the greatest risk of exposure. 

Comprehensive Risk Mitigation 

This Interim Decision complements the 2024 National Emissions Standards for Hazardous Air Pollutants (NESHAP), creating a combined approach to address EtO pollution under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Clean Air Act. EPA’s combined actions target EtO-related cancer risks, improving safety for communities and workers while ensuring the availability of sterilized medical supplies. 

Key Measures for Commercial Sterilizers 

Phased Worker Exposure Limits: 

 EPA is implementing a reduction in permissible worker exposure to ethylene oxide (EtO) in phases, lowering the limit to 0.5 ppm by 2028, 0.25 ppm by 2030, and 0.1 ppm by 2035. These limits are significantly stricter than the current OSHA standard of 1 ppm. 

New Sterilization Standards: 

 A maximum EtO concentration of 600 mg/L will be required for new medical device sterilization cycles within 10 years. If a higher concentration is needed due to device design, facilities must provide justification and maintain supporting documentation. 

Use Cancellations: 

EPA has banned the use of EtO for museum and archival materials, cosmetics, musical instruments, and beekeeping equipment immediately. Additionally, the agency will phase out the use of EtO for specific dried herbs and spices where safer, effective alternatives exist. 

Facility Safety Improvements: 

Commercial sterilization facilities must separate HVAC systems to reduce EtO exposure in areas such as offices. Continuous air monitoring and breathing zone testing will be required to assess exposure levels. Workers performing high-risk tasks such as handling EtO containers must use respirators for protection. 

Healthcare Facility Requirements: 

Healthcare facilities that use more than 10 pounds of EtO per year must install a batement devices to reduce emissions. EtO used in these facilities must be vented through exterior ventilation stacks to limit exposure. EPA considers the community risk from healthcare facilities to be minimal, given their comparatively low volumes of EtO use. 

Next Steps 

Registrants are required to submit label amendments within 60 days of publication of the Interim Decision. New safety measures will be implemented over a 2–10 year period to balance health protections with supply chain stability. EPA will also issue a Data Call-In (DCI) to collect real-world data on worker exposure at commercial sterilizers and warehouses. The agency plans to reassess the decision in eight years, which is earlier than the typical 15-year pesticide review cycle.