MSHA final rule on respirable crystalline silica under White House review

Washington — A long-anticipated Mine Safety and Health Administration final rule intended to reduce miners’ exposure to silica has been sent to the White House Office of Management and Budget for review.

Advancing a rule to OMB, which is under the Office of Information and Regulatory Affairs, is one of the final steps in the regulatory process.

The rule would lower the PEL for respirable crystalline silica to 50 micrograms per cubic meter of air – half the current limit – over an 8-hour time-weighted average. It also would increase silica sampling and enforcement at metal and nonmetal mines.

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 silicosis, defined by NIOSH as “an irreversible but preventable lung disease.”

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

The rule has been under OMB review since Jan. 12. A proposal was published on July 13.

“The purpose of this … rule is simple – to better protect miners from exposure to silica so they do not have to suffer from entirely preventable debilitating and deadly occupational illnesses,” MSHA head Chris Williamson says on an agency webpage about the silica rulemaking. “Silica overexposures have a real-life impact on a miner’s health.”

During a Jan. 25, 2023, conference call with MSHA stakeholders, Williamson discussed the path the rulemaking has taken since first appearing in the Spring 1998 regulatory agenda. The agency at that time forecasted a proposed silica rule would be in place in December 1998, he said.