MSHA’s recent silica rulemaking publication seeks to clarify compliance obligations. The overview below summarizes the current status of the 2024 Silica Rule and its practical impact on the mining industry.
The Mine Safety and Health Administration (MSHA) has delayed its standard on respirable crystalline silica pending judicial review.
On April 18, 2024, MSHA published its final rule, Lowering Miners’ Exposure to Respirable Crystalline Silica and Improving Respiratory Protection, 89 Fed. Reg. 28218 (2024 Silica Rule).
The 2024 Silica Rule established a standard for lowering the permissible exposure limit for respirable crystalline silica at mining operations. The rule also amended existing safety and health regulations for metal and nonmetal mines to align with the new exposure limit. MSHA originally scheduled the amendments for metal and nonmetal mine operations to take effect on April 6, 2026 (and for coal mines, April 2025).
Following publication, industry groups challenged the 2024 Silica Rule. The court ordered MSHA to stay the compliance deadlines in the 2024 Silica Rule pending judicial review.
On April 6, 2026, MSHA published a notification delaying the compliance deadlines provided by the amendments to the existing standards for metal and nonmetal mines in 30 C.F.R. §§ 56–57. While MSHA describes the compliance deadline delay as “indefinite,” the notice later states that the existing standards remain in effect only “[u]ntil the court’s stay is terminated.”
Essentially, MSHA used the notice as a mere formality to (1) acknowledge that the court paused certain compliance requirements in the 2024 Silica Rule until resolution of the rulemaking challenge, and (2) remind the mining industry that mine operators must remain in compliance with preexisting standards.
The impacted conforming amendments regarding exposure limits and control for airborne contaminants include 30 C.F.R. §§ 56.5001T, 56.5005T, 57.5001T and 57.5005T.
The existing standards set forth in 30 C.F.R. §§ 56.5001, 56.5005, 57.5001 and 57.5005 remain in effect until the court terminates the current stay.
