The Peril of Ethylene Oxide: Replacing One Public Health Crisis with Another

Nine months ago, residents of the Chicago suburb of Willowbrook, Illinois, scored a major victory in their fight to prevent emissions of a dangerous gas, ethylene oxide, into the air they breathe. In fact, their victory appeared to have ripple effects in other communities. But like so many other aspects of life in the midst of a pandemic, things changed in a hurry.

The U.S. Environmental Protection Agency (EPA) classified ethylene oxide, or EtO, as a human carcinogen in December 2016. According to the agency, exposure via inhalation increases the likelihood of developing certain cancers and other respiratory and neurological ailments. EPA has not established a reference dose, or maximum acceptable dose, for EtO, but the U.S. Agency for Toxic Substances and Disease Registry’s (ATSDR) Cancer Risk Evaluation Guide (CREG) estimates concentrations of a carcinogen at which there is an elevated risk of one additional cancer case in one million people exposed over a lifetime. ATSDR’s CREG for ethylene oxide is 0.00021 µg/m3.

Despite being classified as harmful, EtO is used to sterilize nearly half of all medical devices that require sterilization in the United States. EPA’s 2016 Toxics Release Inventory identified more than 100 facilities in the United States that emit ethylene oxide into the air. Many of the communities exposed to this carcinogen are made up of primarily Black, Brown, and low-wealth families.

In August 2018, a group of Willowbrook residents came together in response to mounting evidence that EtO emissions from a nearby medical device sterilization facility, owned by a company named Sterigenics, was a threat to their health. That month, ATSDR published an analysis concluding that “an elevated cancer risk exists for residents and off-site workers in the Willowbrook community surrounding the Sterigenics facility.” All of the five-year modeled and 12-hour measured EtO concentration averages exceeded ATSDR’s CREG for EtO. According to the agency, the residential sample location had an additional lifetime risk of 6.4 cancer cases per 1,000 people, which greatly exceeds EPA’s acceptable cancer risk threshold of 100 cases per 1 million.

In 2019, facing pressure from the newly formed grassroots group Stop Sterigenics, the Illinois Department of Public Health published a study revealing an elevated incidence of non-Hodgkin's lymphoma and breast cancer in the census tracts near the Willowbrook facility. Each piece of new information added fuel to residents' campaign to eliminate EtO emissions. In June, state lawmakers passed SB1852, requiring plants to reduce ethylene oxide emissions by 99.9 percent. Then just three months later, in September 2019, Sterigenics decided to permanently shut down the facility due to an “unstable legislative and regulatory landscape.”

The achievement was not only a win for residents of Willowbrook, but helped launch a successful campaign to close a similar plant in Lake County, Illinois, where blood samples from 93 people living within half a mile from a medical device sterilization facility had EtO levels 50 percent greater than those living farther away, whose results closely resembled background levels. Similarly, in Cobb County, Georgia, one of the five medical device sterilization plants operating in the state closed indefinitely after it was unable to comply with additional safety regulations imposed by the county. By the start of 2020, dozens of lawsuits had been filed against Sterigenics by Willowbrook residents seeking justice for years of exposure to the toxic gas.

Then came the coronavirus.

As COVID-19 cases started to climb and hospitals became increasingly concerned about the impending influx of patients and supply shortages, sterilization facilities were once again in demand. While the Willowbrook plant remains closed, the Lake County facility reopened in March. The plant in Cobb County also reopened following arm-twisting by the U.S. Food and Drug Administration (FDA). And while these facilities have installed emission controls, residents are understandably skeptical. Last month, the Lake County Health Department released EtO air monitoring data but has yet to publish its analysis.

Recognizing that the demand for sterilization facilities was on the rise, in March 2020, the EPA Office of Inspector General issued an alert that the agency was not adequately informing people who live near EtO facilities about elevated cancer risks. The Centers for Disease Control and Prevention (CDC), Occupational Safety and Health Administration (OSHA), and 3M also caution against using EtO to disinfect N95 masks. CDC warns that the sterilized masks may give off EtO vapors that will be inhaled by health care workers wearing them. Instead, the agency recommends using safer sterilization alternatives, like hydrogen peroxide.

Such concerns notwithstanding, Charlie Mills, CEO of Medline Industries, another medical device sterilization company, is pressuring FDA to authorize plants to disinfect N95 masks.

This debate over EtO underscores a question public health experts have asked themselves for decades: Should we address one public health crisis by potentially creating another?

It is beyond question that medical device sterilization operations are necessary. And identifying a safe alternative to EtO for mass medical device sterilization requires time, a luxury we unfortunately don’t have in the midst of this pandemic. However, rather than bend to the will of sterilization companies seeking to regain power and money, FDA should continue seeking safer alternatives to EtO and limit reopened facility operations to critical medical equipment that cannot be adequately sterilized with hydrogen peroxide. EPA should update its regulation for EtO emissions and include cancer risks in its review, and it should require companies to monitor and report emissions. They can be sure that the communities who will bear the brunt of their decisions are watching.

UPDATE (8/18/20): If you're interested in learning more about COVID-19 and ethylene oxide, check out a new factsheet from Coming Clean. It highlights key talking points on the issue and what federal agencies can do to protect communities and health care workers from harm.