Director, Office of Standards, Regulations, and Variances

1219-AB36 201804 Unified Agenda of Federal Regulatory and Deregulatory Actions 1219 Mine Safety and Health Administration MSHA 1200 Department of Labor DOL Respirable Crystalline Silica

Current MSHA standards limit exposures to quartz (crystalline silica) in respirable dust. Overexposure to crystalline silica can result in some miners developing silicosis, an irreversible but preventable lung disease, which ultimately may be fatal. The metal and nonmetal mining industry standard is based on the 1973 American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values formula: 10 mg/m3 divided by the percentage of quartz plus 2. The formula is designed to limit exposures to 0.1 mg/m3 (100 ug/m3) of silica. The National Institute for Occupational Safety and Health (NIOSH) recommends a 50 ug/m3 exposure limit for respirable crystalline silica. MSHA continues to review to determine an appropriate next step that would address miners' exposure to respirable crystalline silica.

]]> Other Significant Previously Published in The Unified Agenda Long-Term Actions No No Regulatory 30 CFR 58 30 U.S.C. 811 No Next Action Undetermined To Be Determined Undetermined Businesses Governmental Jurisdictions Local State No Undetermined No No Sheila McConnell Director, Office of Standards, Regulations, and Variances 1219 Mine Safety and Health Administration MSHA 202 693-9440 202 693-9441 mcconnell.sheila.a@dol.gov 201 12th Street South, Room 4E401, Arlington VA 22202-5452