CHICAGO (CBS) — The Illinois EPA has shut down sterilization operations at Sterigenics, a Willowbrook company accused of covering up the release of a cancer-causing gas .

Illinois EPA Acting Director issued the so-called “seal order” to prevent any new medical equipment sterilization processes using ethylene oxide, which is known to cause cancer. It is the main ingredient used to sterilize medical equipment, such as surgical tools.

The move comes after excessively high ethylene oxide readings found in recent tests.

“The Illinois EPA and Illinois Attorney General’s Office have been in numerous discussions with Sterigenics to discuss how to further reduce ethylene oxide emissions,” the Illinois EPA said a a release sent Friday. “Recent elevated sampling results, along with Sterigenics’ refusal to voluntarily suspend operations, have resulted in the issuance of the Seal Order.”

A group of U.S. senators and representatives Wednesday called for the EPA to “open a criminal investigation into allegations of misconduct raised by former employees against senior management at Sterigenics” after two former employees spoke exclusively to the CBS 2 Investigators about warning alarms being rigged allowing excessive ethylene oxide in the facility.

Former Sterigenics employees allege the company ordered workers to dump toxic chemicals directly into the public sewer system. It also covered up just how much was released into the air, including cancer-causing ethylene oxide, they say. It is the main ingredient used to sterilize medical equipment, such as surgical tools.

According to the Illinois Environmental Protection Agency, the chemical is linked to several cancers. The CBS 2 Investigators obtained documents showing the EPA warned the company 35 years ago that ethylene oxide caused stomach cancer.

News of the plant’s shutdown was celebrated at Willowbrook Village Hall Friday night, where officials gathered to discuss what’s next for the community.

Willowbrook Mayor Frank Trilla said the village would fight as long as necessary to see justice.

Calling the EPA’s decision a “tremendous victory,” Senator John Curran said the entire ordeal could have been avoided.

“This has been a long long road,” Curran said. “It didn’t have to come to this. They could’ve worked with us but instead they refused. They ignored this community they ignored the health and concerns of residents of this community—and put us on this road, this eight-month ordeal.”

Congressman Dan Lipinski said the plant’s closure was the beginning of a long battle to bring justice to the community. Numerous lawsuits are expected to follow the plant’s closure, he said.

“It’s not the end because we know there’s more to come,” Lipinski said.

In a press statement, DuPage County Board Chairman Dan Cronin credited local and state agencies for their “dogged determination to gather critical testing information and act on behalf of the residents impacted.”

“Achieving this outcome took months of painstaking work and critical attention to detail,” he said. “Nothing is more important than the health and safety of the people living near this plant.”