MSHA Proposes Changes to 2024 Silica Dust Rule for Mines
Medical surveillance, exposure monitoring and other silica requirements would change for miners, but the permissible exposure limit and action level would stay the same.
- By Danielle Naidu
- Nov 13, 2026
Requirements that address miners' crystalline silica exposure would be revised under a proposed rule the U.S. Department of Labor's Mine Safety and Health Administration (MSHA) released Nov. 10. Crystalline silica is also referred to as quartz dust or silica dust. The proposal is meant to better guard miners against silica-related health hazards, MSHA said.
MSHA's proposal would amend the 2024 rule with changes the agency described as risk-based. They cover medical surveillance, compliance requirements, recordkeeping, exposure monitoring and respiratory protection drawing on OSHA standards.
For respirable crystalline silica, the proposal would leave the permissible exposure limit unchanged at or below 50 micrograms per cubic meter of air. The 25-microgram action level would also remain in place.
Public comments will be due 60 days after the Federal Register publishes the proposed rule, MSHA said. After that publication, the agency also will announce a date for a public hearing.
Several developments since the 2024 rule's publication led MSHA to write a new proposal, the agency said. Among them was a stay the U.S. Court of Appeals for the 8th Circuit placed on the rule's compliance deadlines.
Citing the stay, MSHA said in an April program information bulletin that it would put off enforcing the 2024 rule's requirements. Existing standards would still be enforced, the bulletin said.
About the Author
Danielle Naidu is assistant editor for Occupational Health & Safety and Environmental Protection Online.