Starting in 1984, the Sterigenics plant in Willowbrook, IL consistently emitted a chemical known as ethylene oxide into the air. These air emissions continued until February 15, 2019 when Illinois EPA ordered Sterigenics to stop operating because it found that Sterigenics’ emissions posed a danger to public health.
Ethylene oxide is a colorless, flammable, gas which Sterigenics uses to sterilize medical and other equipment. In the summer of 2018, the Agency for Toxic Substances and Disease Registry (a branch of the CDC), alerted the Willowbrook community that there is an elevated cancer risk for residents and those who work in the community near the Sterigenics plant. Using air samples taken by EPA in commercial and residential areas within a mile of the plant, ATSDR estimated that Sterigenics’ ethylene oxide emissions were making nearby residents 64 times more likely to get cancer.
On May 29, 2019 U.S. EPA hosted an Open House and Community Meeting to provide an update on its work to better understand the ethylene oxide emissions from the Sterigenics facility. At the meeting, U.S. EPA updated the community on the air testing it conducted over 49 days between mid-November 2018 and the end of March 2019. The Agency tested the air at 8 locations within a couple miles of the facility for ethylene oxide. The graph below shows that the levels of ethylene oxide that U.S. EPA found in the air while the plant was still operating dropped significantly after the plant was forced to close. This drop in emissions led U.S. EPA to conclude that the facility is responsible for a significant amount of the ethylene oxide detected.