Silica Dust Exposure Standard Changes Proposed to Protect Miners

The U.S. Department of Labor and the Mine Safety and Health Administration today announced proposed changes to federal standards to reduce respirable crystalline silica, or silica dust, exposure risk for mine workers.

The proposed rule would require mine operators to maintain miners’ permissible exposure limit to respirable crystalline silica at or below 50 micrograms per cubic meter of air for a full shift exposure, calculated as an 8-hour time weighted average. If a miner’s exposure exceeds the limit, the proposed rule would require operators to take immediate corrective actions. Other proposed changes include conducting exposure sampling, providing medical surveillance at no cost for metal and non-metal miners, and updating respiratory protection requirements to reflect current technology.

Unhealthy levels of silica, a carcinogen, and exposures over time can cause severe illnesses, including silicosis and pneumoconiosis. The proposed standard will be published in the Federal Register and public hearing will be held in Arlington, Va., and Denver, Colo. The hearings will be open for in-person or online participation, officials said. Here is a copy of the proposed rule: Lowering Miners’ Exposure to Respirable Crystalline Silica and Improving Respiratory Protection.