Jump to main content.


Chemical Search Banner

Ethylene Oxide (ETO): Hospitals and Healthcare Facilities Must Use a Single Chamber when Sterilizing Medical Equipment with ETO

Current as of March 2010

Implementation of New Label Restrictions to Protect Hospital and Healthcare Facility Employees from ETO Exposure

Note: This fact sheet is NOT related to EPA’s National Emission Standards for Hazardous Air Pollutants (NESHAP), which regulate air emissions from hospitals that are area sources of ETO.

After February 28, 2010, a single chamber process (that is, sterilization and aeration occur in the same chamber) is required for ethylene oxide (ETO) treatment of medical equipment and devices in hospitals and healthcare facilities. Healthcare facilities include nursing homes, diagnostic and major surgery facilities, doctor’s offices, clinics, and other outpatient facilities. This measure is expected to lower ambient levels of ETO in hospitals and healthcare facilities, reducing potential long-term non-cancer and cancer risks for hospital and healthcare facility workers. EPA announced the February 28, 2010 deadline in its 2008 ETO Reregistration Eligibility Decision to give hospitals and medical facilities time to come into compliance.

Manufacturers of ETO have updated their product labels to state:

“After February 28, 2010, a single chamber process is required for ETO treatment (sterilization and aeration are to occur in the same chamber) in hospitals and healthcare facilities.”

Hospitals and healthcare facilities should check their current stock of ETO canisters to see if the labels bear this statement.

Hospitals may choose to send some of their medical equipment to contract facilities for sterilization to ease their transition to a single chamber sterilization process. Contract sterilization facilities are not required to adopt the single chamber process. Instead, they may elect to have employees wear respirators.

EPA’s Review and Decision Regarding the Required Use of a Single Chamber for ETO Sterilization

During EPA’s periodic review of ethylene oxide, EPA found that ETO has the potential to cause adverse health effects to hospital workers from long-term (greater than 6 months) inhalation exposure. For hospital and healthcare facility workers who are involved with the ETO sterilization process (e.g., loading/unloading ETO chambers, changing/maintaining ETO tanks), both long-term non-cancer and cancer risks are of concern. Further, other hospital and healthcare facility workers who are not involved with the ETO sterilization process may also be at risk from long-term ethylene oxide exposure.

Meanwhile, the public health benefits associated with the use of ETO to sterilize medical equipment are extremely high. Given the high health benefits of ETO use and the lack of any feasible replacements for ETO use in sterilizing certain medical equipment/devices, EPA has determined that ETO use on medical equipment in hospitals may continue. However, to mitigate potential non-cancer and cancer risk concerns for workers exposed to ETO as a result of medical use, a single chamber treatment process must be adopted.

EPA’s Regulations Controlling Air Emissions from Hospital Sterilizers using Ethylene Oxide

This single chamber requirement is independent of EPA’s National Emissions Standards for new and existing hospital sterilizers that emit ETO. These emissions standards control ETO emissions to the outdoor environment, whereas the single chamber requirement seeks to reduce occupational exposures to hospital and healthcare facility workers that work indoors. In 2007, EPA issued new requirements for hospitals that are area sources within the meaning of the Clean Air Act. 72 Fed. Reg. 73611 (December 28, 2007). Under this rule, hospitals that are area sources for ETO are required to, inter alia, institute management practices and collect records to reduce ETO emissions.

For Further Information

For more information regarding EPA’s single chamber requirement for ETO sterilization and EPA’s human health risk assessment, please see the 2008 Ethylene Oxide Reregistration Eligibility Decision. For further assistance, please contact Dennis Edwards (edwards.dennis@epa.gov) at 703-308-8078.

For more information regarding EPA’s National Emissions Standards for Ethylene oxide, please visit EPA’s website at http://www.epa.gov/ttn/atw/eo/eopg.html. For further assistance on this matter, please contact Hillary Ward (ward.hillary@epa.gov) at 919-541-3154.

Top of page

Publications | Glossary | A-Z Index | Jobs


Local Navigation


Jump to main content.