Since 2009, coal miners and their allies have pushed the federal government to implement a silica dust standard to prevent exposure to the silica dust implicated in the causation of severe forms of coal worker pneumoconiosis, or black lung disease. In April 2024, a silica dust rule was finally issued, with the coal industry given one year to comply. However, the Trump Administration and the mining industry took steps to halt the enforcement of the rule and in April of 2025, Trump’s MSHA announced it would halt enforcement of the rule. Nearly simultaneously, the Eighth Circuit Court of Appeals put an indefinite stay on the rule after the mining industry took the rule to court and the administration failed to oppose the industry’s petition. Since then, parties in the case, including Trump’s MSHA, requested an abeyance on court action as MSHA agreed to weaken the rule to appease industry’s complaints. Now that MSHA and the industry are in agreement, MSHA says they can’t advance even the watered down rule while the court’s stay is in place.
As the delays continue and no silica dust standard is in place for coal mines, we have assessed ongoing silica dust sampling by MSHA to better understand whether mines would be in compliance if the 2024 rule were in place. We have assessed silica dust sampling at coal mines since the intended effect date of the rule in April 2025 and compared results to the standards set in the delayed rule. We found:
- 20 percent of surface and underground mines sampled for silica in 2025 had dangerous and toxic levels of silica dust.
- Samples at 12 mines in 2025 revealed exposure levels of more than double what was proposed as the permissible exposure limit in the 2024 silica dust rule.
- The above two trends have continued in Q1 of 2026. In Q1 alone, six mines revealed exposure levels of more than double what was proposed as the permissible exposure limit in the rule.
Silica dust exposure is the driving factor behind the resurgence of black lung disease in central Appalachia, and the lack of a strong federal silica dust standard has put the lives of countless miners at risk. Now, MSHA’s own data shows that dozens of mines would be out of compliance with the rule that was to be implemented in 2025 before the Trump Administration’s involvement and subsequent indefinite delays. With 20% of active mines registering toxic levels of silica dust exposure for miners based on MSHA’s own samples in 2025 (and 20% thus far within underground mines in 2026), the need to end these delays and implement a strong silica dust standard is clear. According to the now-delayed rule finalized in 2024, samples breaching the 50 μg/m³ threshold would trigger immediate corrective measures to reduce dust and additional sampling to ensure that corrective measures reduced dust levels to a state of compliance with the permissible exposure limit of 50 μg/m³.
With MSHA’s own samples showing imminent danger for miners, every day of delay creates a greater likelihood of silica dust exposure that can cause black lung and cost miners their lives. As the rule remains unenforced, ACLC will continue to monitor miner overexposures to silica dust.
Read our full analysis here.
