Gov. J.B. Pritzker’s administration on Friday banned Sterigenics from using ethylene oxide at its Willowbrook sterilization plant, responding to an intense public outcry about toxic air pollution that left surrounding neighborhoods with some of the highest cancer risks in the nation.

The state’s new governor ordered the Illinois Environmental Protection Agency to step in a week after the Trump administration told residents it still didn’t have enough evidence to take action against the Oak Brook-based company, which is owned in part by a private equity fund co-founded by former Gov. Bruce Rauner.

Federal testing in Willowbrook, Burr Ridge and Darien during late November and December revealed spikes of the volatile gas that were higher than concentrations detected before the company installed new pollution-control equipment last year.

The Chicago Tribune first reported that EPA officials began taking a closer look at Sterigenics in late 2017 after determining the cancer risks in one census tract near the facility are more than nine times higher than the national average. By the time the EPA quietly posted its findings online in August, another federal agency had estimated the effects could be significantly more dire, prompting an intense public outcry and demands from local, state and federal lawmakers for an in-depth investigation.