Respirable Crystalline Silica Standard

MSHA proposes to lower the existing exposure limit (PEL) for respirable crystalline silica from 100 µg/m3 to 50 µg/m3 at mining operations due to the serious health hazard such exposure presents to miners. Exposure at the existing PEL is known to cause silicosis, an irreversible but preventable lung disease; non-malignant respiratory disease (other than silicosis); lung cancer; and renal and autoimmune effects in susceptible individuals. The proposed rule, once implemented, would significantly enhance health protection for metal and nonmetal miners as well as coal miners. MSHA’s proposed respirable silica rule includes provision for lowering the respirable crystalline silica permissible exposure limit; MSHA’s longstanding practice that the hierarchy of controls be used at metal and nonmetal as well as coal mines to lower exposures; prohibiting rotation of miners for compliance with this rule; a written respiratory protection program; medical evaluation and transfer rights for metal and nonmetal as well as coal miners who are medically unable to wear required respiratory protection under this standard; exposure assessment and monitoring, including rights of miners or their representatives to observe monitoring and have access to records; medical evaluation of miners’ health; and recordkeeping. Proposed paperwork requirements would be contained in a written respiratory protection program, involve medical records, copying and posting of sampling results, and the creation and maintenance of records.

The latest form for Respirable Crystalline Silica Standard expires 2027-05-31 and can be found here.