An activist-driven effort to shut down medical sterilization plants around the country has already contributed to medical supply shortages during the COVID-19 pandemic, and it needs to stop. These groups want to eliminate the use of the gas ethylene oxide (EtO) in the sterilization of medical supplies because they say EtO emissions cause cancer. Yet the science doesn’t support that assertion, and if activists succeed, public health will suffer.

EtO is a gas that naturally enters air from vegetation, manure, volcanic eruptions, waterlogged soil, and combustion related to automobile traffic, smoking, fires, and many other sources. Humans inhale some, but it’s also naturally formed inside the human body through our metabolic processes, and we release it as waste products. According to the Environmental Protection Agency (EPA), the body releases it “fairly quickly,” with levels falling by “50% every 42 minutes.”

EtO has been used for decades for medical supply sterilization, with the understanding that trace emissions from these facilities were too low to pose significant risks. Public perception changed when an EPA research program known as the Integrated Risk Information System (IRIS) released a highly flawed assessment of EtO risks in 2016.

The assessment set an absurdly restrictive “reference concentration”—an agency-determined safe level for people who continuously inhale the gas—for EtO at 0.1 parts per trillion or 0.0000001 parts per million. By comparison, the Occupational Safety and Health Administration (OSHA) safety standard is one part per million, and that’s for workers exposed five days a week, eight-hours a day for decades. There’s no evidence that at the current OSHA standard workers are suffering any ill effects, indicating that EPA’s reference dose is way off the mark.

“Ethylene oxide is suddenly getting attention because an office within the EPA changed the way it calculated the amount it considers safe to breathe,” explained toxicologist Gail Charnley, in a 2019 statement. “No new science was used, just new math.”

Charnley pointed out that the number is nearly 20,000 times lower than the amount produced naturally in the human body, is 5,000 times lower than levels normally found in suburban air, and more than “5 million times more stringent than the scientific judgements underlying all other regulatory limits on ethylene oxide in the United States and worldwide.”

After EPA released its controversial IRIS assessment, the Texas Council on Environmental Quality (TCEQ) launched its own scientific investigation to determine if it should revise its standard. The state recently reported that IRIS’s methods were highly flawed, and it found that the chemical is even less dangerous than the state originally determined years ago. Accordingly, the TCEQ increased the acceptable level of background concentrations from two parts per billion to two and a half parts per billion, which is many multitudes higher than the EPA reference dose.

Despite these realities, Chicago Tribune journalists have been using IRIS’ junk science to peddle sensationalist stories about the risks. Starting in 2018, their hype help set off a health scare that led to the permanent closure of a facility in Willowbrook, Ill., in September 2019. Several other facilities temporarily closed as well during 2019 into early 2020.

As plants closed, the U.S. Food and Drug Administration (FDA) sounded a legitimate alarm, issuing repeated warnings last year—in March, September, and October—that these closures could lead to shortages of medical supplies. At a U.S. Food and Drug Administration (FDA) meeting with expert advisers last November—long before public awareness of COVID-19—participants expressed grave concerns about potential shortages, particularly if a medical emergency were to arise.

In any case, the impact of such closures promised to be substantial with or without a COVID-19 resurgence. Less than 1 percent of commercially produced EtO is used to sterilize more than 20 billion medical products—more than half of all sterile medical products in the United States. FDA notes that for many products, “ethylene oxide may be the only method that effectively sterilizes and does not damage the device.”

When supply shortages became severe during the COVID-19 crisis, some of these facilities fortunately reopened at the behest of the FDA. EPA followed up in the spring with new rule that tightened emission standards for these facilities in an exercise of excessive caution.

And during the past couple of years, EPA collected data on the levels found outside the facilities in Illinois and Georgia, and found that the levels are not alarming. “No doubt, scientific truths are desperately needed in the public dialogue,” Charnley explained. “The most important truth being, there is no cancer threat from the tiny amounts of ethylene oxide released from these sterilization plants.”

It’s understandable that people within these communities may be afraid because of a steady stream of misinformation and fearmongering. But at some point, reason must prevail, or there will be real and dangerous consequences when supplies for basic medical products dry up.