Ethylene oxide from sterilization facilities poses cancer risks

Ethylene oxide, a gas commonly used to sterilize medical equipment and spices, poses health risks to workers and communities surrounding sterilization facilities, the US Environmental Protection Agency says in a draft risk assessment.

The EPA conducted the evaluation as part of the reregistration review process for pesticides. The agency regulates the use of ethylene oxide as a sterilant, which it considers an antimicrobial pesticide.

The draft assessment, released Nov. 19, provides a route for the EPA to tighten regulations on ethylene oxide releases from sterilization facilities. The agency has been evaluating options for reducing ethylene oxide emissions since a 2016 assessment showed that cancer risks are greater than the EPA previously thought. In its August 2018 air toxics screening assessment, the EPA pointed to ethylene oxide emissions from commercial sterilization facilities as a major contributor to the elevated cancer risks.

Ethylene oxide “is used on half of all sterilized medical devices in the United States annually and, in some cases, it is the only sterilization method available,” Alexandra Dunn, assistant administrator of the EPA’s Office of Chemical Safety and Pollution Prevention, says in a statement.

The EPA’s assessment calls for measures to protect workers in sterilization facilities and surrounding communities. These measures could include requiring workers to wear respirators, upgrading technologies for capturing ethylene oxide emissions, and increasing air monitoring, the agency says. The EPA is accepting public comments on the draft assessment until Jan. 19, 2021. Once the agency finalizes the assessment, it will propose various controls to reduce any risks.

In the meantime, the agency is also reviewing regulations under the Clean Air Act for controlling emissions of ethylene oxide from sterilization facilities. In December 2019 and June 2020, the EPA requested information from such facilities regarding sources of ethylene oxide emissions and control technologies. The agency is also collecting data on background levels of ethylene oxide at nonindustrial air monitoring sites.

The EPA will use the data to support its ongoing review of national hazardous air pollution standards for ethylene oxide. Earlier this year, the agency required chemical manufacturers to reduce ethylene oxide leaks at their plants.