What is ethylene oxide?
Ethylene oxide is a widely used chemical made in the U.S. by some of the industry’s global giants, including Dow Chemical, Huntsman, Shell and Union Carbide. Its main use is in the refining of other chemicals, including ethylene glycol, the main ingredient in automobile antifreeze.
A small but significant percentage of ethylene oxide is used by hospitals and corporations to sterilize medical instruments. It also is used to fumigate pharmaceutical drugs and food, in particular spices.
Ralph Landau, a chemical engineer who pioneered a widely used process for making ethylene oxide, later developed a new method to make ethylene glycol that didn’t rely on its more troublesome chemical cousin. A company he formed to manufacture products without ethylene oxide foundered in the early 1980s.
The dangers of ethylene oxide have been known since at least the late 1970s. In 1985, the National Toxicology Program, an arm of the U.S. Department of Health and Human Services, declared that the chemical is “reasonably anticipated to be a human carcinogen.” The government scientific agency classified ethylene oxide as a “known human carcinogen” in 2000.
One of the chief studies of its cancer risks involved more than 18,000 workers at sterilization plants. Researchers for the National Institute for Occupational Safety and Health found that the workers suffered worrisome rates of breast cancer and lymphomas. The study provided the foundation of a draft risk assessment issued in 2006 by the U.S. Environmental Protection Agency, a document that wasn’t formally released until December 2016.
Ethylene oxide producers and users contend the chemical is vitally needed to prevent hospital infections. Other sterilization methods used by Sterigenics and its corporate competitors include steam, gamma rays and hydrogen peroxide gas, which present fewer environmental drawbacks and are generally safer.