A Montana company that converts mining waste into roofing materials was fined and ordered to undergo medical surveillance after admitting to exposing its employees to arsenic

Bit, Monte. -A company that converts mining waste into roofing materials at a Montana factory was fined on Friday and ordered to conduct medical surveillance on workers after pleading guilty to a criminal charge of exposing employees to arsenic.

According to court records, US Minerals, headquartered in Tinley Park, Illinois, was fined $393,200 by U.S. District Judge Dana Christensen and suspended for five years. The company pleaded guilty to negligent harm in August, a misdemeanor of violating the Federal Clean Air Act.

Prosecutors said that despite repeated warnings from regulators, US Minerals continues to poison its workers by exposing them to arsenic. According to the World Health Organization, long-term exposure to inorganic arsenic can cause skin cancer, bladder cancer and lung cancer.

The company admitted in its guilty plea that it "inadvertently placed another person in imminent danger of death or serious bodily harm."

Closed from 2013 to June 2021, the company's Anaconda factory converted mining waste known as black slag (a by-product of the town's century of copper smelting) into roofing materials called Black Diamond Abrasive Products.

According to the plea agreement, U.S. mining companies’ factories in Illinois, Wisconsin, Kansas, Texas, and Louisiana will be subject to enhanced supervision by the Environmental Protection Agency and the Occupational Safety and Health Administration during a five-year trial period .

During this period, the company must also monitor the health of former employees at the Anaconda plant.

According to the agreement, employees who use the medical monitoring program will not give up their right to file a civil lawsuit against American mining companies.

According to a 2016 report from the National Institute of Occupational Safety and Health, five of the six employees tested at the Anaconda plant in July 2015 had elevated arsenic levels. At the time, respiratory protection was provided but not required, and the factory did not have running water or hand washing stations

The company was fined nearly $107,000 by OSHA for violations in 2016.

The Montana Department of Health ordered the temporary closure of the plant in February 2019 after the arsenic level in the urine of at least two workers increased in 2018.

24/7 coverage of breaking news and live events