The U.S. Department of Labor’s Mine Safety and Health Administration (MSHA) has announced a proposed rule that would lower miners’ exposure to “respirable” coal dust in all underground and surface coal mines. The proposed rule combines prior regulatory actions addressing coal mine dust exposure, single sample, plan verification, and the continuous personal dust monitor.

The plan would lower the existing concentration limits for respirable coal mine dust from 2 milligrams of dust per cubic meter of air to 1 milligram of dust per cubic meter of air over a 24-month phase-in period. It would also (i) require the use of the continuous personal dust monitor; (ii) provide for the use of a single, full-shift sample to determine compliance; (iii) address extended work shifts; and (iv) redefine normal production shifts. It would also require expanded medical surveillance so that miners could take proactive steps to better manage their health. The proposed rule is part of MSHA’s “End Black Lung–Act Now” campaign. The agency will accept comments for 60 days after it is published in the Federal Register.