PORTLAND, Ore. (KOIN) — A company operating an aluminum processing facility in The Dalles is accused of violating the Clean Air Act and releasing hazardous pollutants that endangered employees, federal prosecutors announced Wednesday.

Hydro Extrusion USA, an Illinois-based company, was charged with negligent endangerment under the Clean Air Act, according to the U.S. Attorney’s Office for the District of Oregon.

“Enforcing emissions standards for hazardous air pollutants is critical to protecting the air we breathe and ensuring companies play by the rules,” said Ethan Knight, Chief of the Economic Crimes Unit for the U.S. Attorney’s Office. “We will vigorously prosecute any company that risks the health and safety of its workers or our communities.”

The company’s secondary facility in The Dalles is used to make reusable aluminum billets by melting aluminum scrap in induction furnaces, according to court documents. Air emitted from the furnaces allegedly bypassed pollution control devices before reaching employees and ambient air.

From June 2018 to June 2019, officials say Hydro used melted scrap aluminum that was coated in a mineral-oil based mixture, which is prohibited under the Clean Air Act. The mixture produces hazardous smoke when combusted.

Hydro allegedly continued to melt the “unclean charge,” despite being notified of excessive smoke by employees, inspectors from the EPA and the Oregon Department of Environmental Quality.

The aluminum supplier reportedly agreed to plead guilty.

The EPA Criminal Investigation Division and Oregon DEQ handled the investigation.