EPA Proposes Changes to Ethylene Oxide Sterilizer Emissions Rule

The U.S. Environmental Protection Agency (EPA) has proposed amendments to the 2024 National Emissions Standards for Hazardous Air Pollutants for commercial sterilization facilities that use ethylene oxide.

According to the agency, the proposal would revise aspects of the 2024 rule governing emissions from facilities that use ethylene oxide, a sterilizing agent commonly used for medical devices and other materials. The proposed changes would remove certain risk-based standards and modify requirements related to emissions monitoring systems, aeration room vents and permanent total enclosure provisions.

Ethylene oxide sterilization is widely used for heat- and moisture-sensitive medical equipment. According to the EPA, approximately half of all medical devices in the United States are sterilized using the gas each year, totaling about 20 billion devices.

In a press statement, the agency said the proposal is intended to ensure the rule aligns with Clean Air Act requirements while maintaining the ability of sterilization facilities to operate. The agency also said it aims to limit unnecessary exposure to ethylene oxide while maintaining the availability of sterilized medical equipment.

The agency is proposing that the Clean Air Act limit residual risk reviews to a single review following the establishment of maximum achievable control technology standards. According to the agency, it previously completed a required review in 2006 and is proposing to remove risk-based standards introduced in the 2024 amendments.

If finalized, the proposal would allow facilities emitting more than 10 tons of ethylene oxide annually to either install a new monitoring system or make adjustments to certain emissions requirements associated with aeration room vents, according to the agency. The agency emphasized that the revisions are intended to provide operational flexibility while maintaining emissions controls.

The agency also said it is seeking public comment on new scientific information related to ethylene oxide exposure and toxicity, including epidemiological studies and updated statistical modeling methods. According to the agency, the review may help determine whether existing toxicity values used for regulatory decision-making remain appropriate.

EPA estimates the proposed changes could reduce compliance costs by about $630 million over 20 years, or roughly $43 million annually, according to the agency.

The agency said it will accept public comments on the proposal for 45 days after publication in the Federal Register and will hold a virtual public hearing 15 days after publication.