The announcement of US workplace regulators on Thursday to limit the crystalline silica dust exposure has been historic. However, the decision sparked off concerns in the construction industry.

Announcing the new rules, the Occupational Safety and Health Administration (OSHA) on Thursday lowered the exposure levels of silica dust for the first time in 45 years.

The carcinogenic silica dust has been a major construction worker killer. Under the new rules, the exposure of silica dust will be restricted to 50 micrograms per cubic meter of air. The limits for others include 250 micrograms for construction and 100 micrograms for all other industries. The construction industry has been given time until June 2017 to comply with the new order.

Silica dust is considered responsible for several deadly lung diseases like silicosis and lung cancer.  According to OSHA, 2.3 million US workers are annually exposed to silica dust but and the new rule would save at least 600 lives a year, reports NBC news.

However, the announcement has been resented by many industry groups, which warned that they will fight in court and the US Congress to repeal the law. Calling the regulation unnecessary, industry groups said the compliance costs of the new rule will run into billions of dollars.

According to US Labor Secretary Thomas Perez, silica-related illnesses have claimed thousands of workers’ lives in the last century.

Law maker, Rosa DeLauro, a Connecticut member of the House of Representatives hailed the decision. “I applaud Secretary Perez and the Department of Labor for taking this step to ensure the health and well-being of employees across the country,” she said.

The US Chamber of Commerce, the American Petroleum Institute and other industry groups had been opposing all efforts at strengthening the silica rule.

Jay Timmons, president of the National Association of Manufacturers, said the new rules are a product of outdated research.

OSHA has put the compliance cost on employers at $1 billion. It also pointed out the resulting net savings between $3.8 and $7.7 billion a year by saving people from costly diseases, reports Huffington Post.