WILLOWBROOK, Ill. — The Illinois Environment Protection Agency has ordered a controversial health equipment sterilization facility in the southwest suburbs to be immediately sealed.

Sterigenics in Willowbrook was ordered to shut down Friday.

It comes after months of concern about the release of potentially cancer-causing levels of chemical ethylene oxide.

“This impact creates an imminent and substantial endangerment to public health or welfare,” wrote John Kim, acting director of the Illinois Environmental Protection Agency.

The order says “emissions are continuing to contribute to ambient levels of ethylene oxide in the atmosphere. This impact creates an imminent and substantial endangerment to public health.”

The move comes after fluctuating levels of ethylene oxide were found in air tests surrounding the Willowbrook facility. The order appears to prevent Sterigencis from continuing to use ethylene oxide until measures are in place to prevent future emissions.

“It won’t be enough until it’s finished or we know they can operate safely. One of those two things has to happen,” said Willowbrook mayor Frank Trilla. “But right now they’re shut down so we’re happy to be in that place.”

For its part, Sterigenics installed equipment last summer to reduce emissions and has previously said the levels of ethylene oxide detected was “well within safety standards.”

Last fall the Chicago Tribune reported former Governor Bruce Rauner’s administration and his team at the Illinois EPA kept quiet “for months” about a federal analysis that linked unusually high cancer risks around the Willowbrook facility to the emissions.

Rauner’s former equity firm owned a portion of Sterigenics.

In a statement, Sterigenics said:

The Illinois EPA’s actions to suspend operations at the Sterigenics Willowbrook facility are indefensible. Sterigenics Willowbrook has consistently complied with all state permits and regulations and Sterigenics has been in ongoing cooperation with the Illinois EPA and other officials regarding the safe operation of the facility.

Unilaterally preventing a business that is operating in compliance with all state permits and regulations from carrying out its vital function sets a dangerous precedent. The Illinois EPA’s decision will place the health and lives of thousands of patients who rely on the critical medical products sterilized at Willowbrook at risk.

In addition, we are in the process of reviewing the air monitoring results released today from the Village of Willowbrook. These results are inconsistent with all prior monitoring results. We will be analyzing these results closely to understand the cause for such inconsistency from all prior samples taken to date.

Sterigenics will comply with the order and will take all legal actions necessary to reverse this decision.

Read the entire IEPA Seal Order (pdf)