MSHA unveils long-awaited proposed rule on respirable crystalline silica

UPDATE: The proposed rule was published in the July 13 Federal Register.

Washington — The Mine Safety and Health Administration has announced a proposed rule on worker exposure to respirable crystalline silica in an effort to better protect miners from associated health hazards.

Workers can inhale silica dust during mining and other operations, including cutting, sawing, drilling or crushing materials such as rock and stone. Crystalline silica can damage lung tissue and lead to black lung disease, chronic obstructive pulmonary disease or incurable silicosis.

The rule would lower the Permissible Exposure Limit for silica to 50 micrograms per cubic meter of air over an 8-hour time-weighted average. It also would mandate exposure sampling and free medical surveillance for metal and nonmetal miners, as well as update standards on respiratory protection.

The proposed PEL is half the previous limit and matches the PEL OSHA established in 2016.

“The purpose of this proposed rule is simple: prevent more miners from suffering from debilitating and deadly occupational illnesses by reducing their exposure to silica dust,” MSHA administrator Chris Williamson said in a press release. “Silica overexposures have a real-life impact on a miner’s health.”

OSHA estimates that 2.3 million workers are exposed to silica dust annually.

Recent research from the University of Illinois Chicago suggests the lung tissue of contemporary coal miners contains higher levels of respirable crystalline silica dust than counterparts of previous generations – which may explain a surge in cases of progressive massive fibrosis, the most severe form of black lung disease.

During a Jan. 25 conference call with agency stakeholders, Williamson detailed the long path the proposal has taken since first appearing in the Department of Labor’s Spring 1998 regulatory agenda. The agency had anticipated a proposed rule on silica would be issued by the end of that year.

Cecil Roberts, president of United Mine Workers of America, said the proposed rule comes “at long last.”

He added: “This is the first step of many that will be required. We must get this rule finalized as soon as possible. And then we must ensure that mine operators follow the rule (and) the government enforces it and penalizes those who violate it.”

MSHA will accept comments on the proposed rule once it’s published in the Federal Register. The agency also plans to host in-person and virtual public hearings in Arlington, VA, and Denver.