The Mine Safety and Health Administration (MSHA) has proposed changes to its 2024 silica rule for miners while enforcement of that rule is still on hold. The proposal keeps the exposure limit but changes how mines monitor exposure, protect workers with respirators, run medical surveillance and keep records.
The proposed rule was published in the Federal Register on Nov. 12, 2026 (91 FR 73062). MSHA will hold a virtual public hearing on Dec. 15, 2026, and written comments are due by Jan. 11, 2027.
What the proposal keeps
The permissible exposure limit for respirable crystalline silica stays at 50 micrograms per cubic meter of air (µg/m³), with an action level of 25 µg/m³, according to MSHA.
What the proposal would change
The proposal modifies MSHA's 2024 final rule, "Lowering Miners' Exposure to Respirable Crystalline Silica and Improving Respiratory Protection." It covers five areas of that rule: methods of compliance, exposure monitoring, respiratory protection, medical surveillance and recordkeeping.
The Federal Register notice names two of the changes:
- Metal and nonmetal miners would get easier access to voluntary medical exams.
- Mine operators would no longer have to make sure chest X-ray classifications are sent to the National Institute for Occupational Safety and Health (NIOSH).
Where the 2024 rule stands
On April 11, 2025, the 8th Circuit Court of Appeals stayed the 2024 rule's compliance deadlines. MSHA has also delayed enforcing the rule and says its existing silica standards still apply.
Rep. Bobby Scott (D-Va.) called the proposal a rollback of miner protections, Safety+Health magazine reported. The National Stone, Sand & Gravel Association, which challenged the 2024 rule in court, welcomed it.
What it means outside mining
Sites regulated by OSHA follow OSHA's own silica standards for general industry (29 CFR 1910.1053) and construction (29 CFR 1926.1153), which also set a 50 µg/m³ limit. MSHA's proposal doesn't change them.
How to comment
Comments must reach MSHA by midnight Eastern Time on Jan. 11, 2027, and must include Docket No. MSHA-2026-0200 or RIN 1219-AC22. Details on the Dec. 15 virtual hearing are in the Federal Register notice.
Mine operators should read the proposal and tell MSHA which changes would or wouldn't work at their sites before the deadline.
Sources:
Arysha Alif Khan
Arysha Alif Khan is an EHS and chemical safety specialist with a background in biochemistry, biotechnology, and public health. She works closely with the product and regulatory teams to turn complex chemical regulations, SDS requirements, and workplace safety standards into clear, practical guidance for people.