The following is a guest column submitted by Angela Logomasini, Senior Fellow at the Competitive Enterprise Institute. Guest columns do not reflect the views of the Center. Instead, these are opportunities to showcase diverse opinions on issues at the intersection of science, justice, and the economy. For more information on how you could submit a guest column to the Center, please email

As a recent Center for Truth in Science report demonstrated, trial lawyers have spawned an entire industry dedicated to identifying potential mass torts based on phony science. These cases eventually force companies to pay huge settlements to avoid protracted and expensive litigation, even when the firms have done no harm. As the plaintiffs’ lawyers’ pocket big fees, consumers eventually suffer the consequences in the form of higher prices, reduced access to valuable products, or worse.

On the horizon are potential mass torts related to the chemical ethylene oxide, a gas that is used to make various consumer products and to sterilize medical supplies and some foods such as spices. It also forms naturally in the environment through combustion, and it’s a byproduct of human metabolism. According to the Environmental Protection Agency (EPA), the human body efficiently and quickly releases the ethylene oxide it produces or inhales within minutes to a few hours of exposure. Ethylene oxide has been studied extensively, used safely for decades, and has a good safety profile for its current uses.

Public perception about its risk began to change in 2016 after EPA released a highly flawed study alleging that it might cause cancer at infinitesimal exposure levels. Produced by an agency research program known as the Integrated Risk Information System (IRIS), this study set a “safe” exposure level for ethylene oxide gas in ambient  air at 0.1 parts per trillion or 100 parts per quadrillion, leading some people to conclude that anything above that level is dangerous.

Yet the IRIS number makes no scientific sense. Consider the fact that, as the American Chemistry Council points out, the human body produces ethylene oxide at a level that is 19,000 times higher than IRIS’ figure. In addition, IRIS’ reference concentration is also 1,000 to 2,000 times lower than the background levels reportedly found in urban air around the nation, which EPA data indicate is about 0.1-0.2 parts per billion. So, if the IRIS figure was correct, our biggest and most dangerous exposures are from our own bodies or low levels of ethylene oxide naturally found in the air.

The IRIS research generated such an absurd figure because it relied on research that vastly over estimated exposures of study participants. The agency relied exclusively on three studies (see here, here, and here). Conducted by National Institute for Occupational Safety and Health (NIOSH) researchers, these three studies all focused on the same cohort of workers who had occupational exposures to ethylene oxide between 1938 and 1985.

Because there were no records on actual exposure levels for this NIOSH cohort, the researchers had to develop estimates. Inexplicably, their estimates assumed workers were exposed to levels far lower than what was most likely at the time. By underestimating exposures, any cancers found among the NIOSH cohort would have appeared to have occurred at exceptionally low exposure levels, which led IRIS staff to develop an excessively cautious figure.  

Other studies with actual measurements demonstrated that workers during the timeframe were, in fact, exposed to much higher levels than estimated for the NIOSH cohort. By and large, these other studies did not find associations between ethylene oxide and cancer, but IRIS researchers disregarded them completely.

Ironically, the NIOSH studies were also largely inconclusive. Overall, the workers had lower cancer rates than the general population, but the researchers reported some weak associations for a few rare cancers—associations that could occur by mere chance. IRIS relied on those few cases to develop an assessment that was out-of-line with most research in the world on this topic.

Unfortunately, IRIS’ faulty assessment had serious consequences because it created health scares in neighborhoods near medical supply sterilization facilities. Medical sterilization plants emit trace amounts of ethylene oxide that have never been shown to pose health problems, and regulations ensure that human exposures remain low.

Yet the IRIS research eventually generated media hype about the risks, which led several state and local governments to respond by shutting down some medical supply sterilization facilities—just as the COVID-19 crisis was developing. Fortunately, by March of 2020, to help resolve medical supply shortages, many of these plants reopened at the behest of the Food and Drug Administration.

Now trial lawyers have identified ethylene oxide as one of their next money-making opportunities. They’ve already filed lawsuits and are hosting websites where they can register potential plaintiffs—anyone who lived near these facilities and happened to get cancer.

The Center for Truth in Science commendably has begun to offer research grants that will fund independent and unbiased research on the topic, which will hopefully deter the advancement of misguided mass torts. Such research is critically important as these torts could have profoundly adverse impacts on our nation’s medical supplies, particularly if they lead to more plant closures.

Angela Logomasini, Ph.D., is a senior fellow at the Competitive Enterprise Institute and is the author of two papers on ethylene oxide, which you can find here and here.