WILLOWBROOK, Ill. —A federal judge has refused to order the resumption of operations at a suburban Chicago plant that sterilizes medical instruments with a cancer-causing chemical.

The state last week issued a seal order for Sterigenics U.S. in Willowbrook. The Illinois Environmental Protection Agency said the order was based on air sampling by local officials and the U.S. EPA that consistently found high outdoor ambient levels of ethylene oxide.

In seeking an emergency order to reopen, Sterigenics attorney Gerard Kelly on Wednesday told U.S. District Judge Matthew Kennelly the plant’s shutdown is “causing a crisis” for its customers. He said medical supply companies will be in a lurch without Sterigenics’ products because it will take them months to find a new place to get what they need.

Illinois EPA attorney Steve Sylvester called ethylene oxide a known human carcinogen. Sylvester added environmental data obtained Tuesday were alarming due to “fugitive emissions.”

Sterigenics released a statement saying:

Today’s hearing was related to Sterigenics’ motion for a temporary restraining order filed in federal court. After deciding federal court is not the appropriate forum, the judge denied Sterigenics’ motion for an emergency order that would lift the Illinois Environmental Protection Agency’s seal order. We are pleased with the court’s decision, though the case will likely continue. In addition, we will continue to pursue our motion to remand the state’s original lawsuit against Sterigenics back to state court.