This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

WILLOWBROOK, Ill. — The federal Environmental Protection Agency says no spikes in a cancer-causing chemical were detected after a suburban Chicago plant that uses the gas was shut down.

The Chicago Tribune reports that EPA documents released Thursday show that six days of reading done while Sterigenics wasn’t operating in Willowbrook found no increased levels of ethylene oxide. The documents show average levels of the chemical were at least 50 percent lower at each of ten monitoring sites after the shutdown. Levels were more than 90 percent lower at testing locations closest to Sterigenics.

Federal officials plan to keep collecting samples through the end of March. Gov. J.B. Pritzker’s administration banned the facility that sterilizes medical instruments from using the toxic gas Feb. 15.

Sterigenics said it is still reviewing the latest EPA findings.