The proposal would eliminate mandatory quarterly testing for silica dust, instead allowing mine operators to test "as frequently" as they deem "necessary." In its rulemaking document, MSHA argues that mine operators have the experience to decide how often to test for the toxic dust. The agency even anticipates that operators might determine some miners are not reasonably likely to be exposed to respirable crystalline silica and therefore skip sampling for those workers altogether.

The change would also limit testing to work environments that mine companies believe are at or above a warning level for silica dust. Currently, mines must test any area where workers could be exposed to any silica dust, as there is no safe level of exposure.

MSHA estimates the reduced monitoring and medical testing would save mine operators a collective $28.7 million annually, with more than 90% of those savings coming from industries other than coal.

While the proposal does not alter the legal exposure limit of 50 micrograms per cubic meter of air set in 2024, it would change how companies can be penalized for exceeding it. Under the Biden-era rule, companies could be fined based on their own dust sampling results. The new proposal would only allow fines based on MSHA inspections, and only if a test shows levels 21% over the limit to account for errors. That means companies could overexpose workers to silica dust levels up to 60 micrograms without any penalty.

Additionally, the rule seeks to remove required initial medical exams for miners outside the coal industry. Such exams are often critical for miners who develop black lung disease to prove their illness is work-related and qualify for federal health benefits.

The Department of Labor, MSHA's parent agency, characterized the changes as "practical, commonsense, risk-based improvements" that would "better protect the nation's miners."

But miner advocacy groups, who fought for decades for tougher silica standards, strongly disagree.

"Amid a black lung epidemic that is the worst it has been in 50 years, the Trump administration proposed a silica dust rule weaker than what miners and miner advocates won in 2024," Brendan Muckian-Bates of the Appalachian Citizens' Law Center said in a press release Tuesday. "The administration said they wanted to bring back coal. Instead, under their watch, they are bringing back black lung."

Vonda Robinson, president of the National Black Lung Association, was furious. "This is just absolutely ridiculous," she said in an interview. "It just upsets me because this is just an earlier death sentence for metal, non-metal and [coal] miners. We're going to fight them tooth and nail. This is not going to happen."

The National Mining Association, an industry group, said it supports stricter silica limits and is reviewing the proposal. "In our initial reading of this proposed rule, it appears to address many of the concerns that we have raised and recommendations we have made to the government for years," spokesperson Ashley Burke wrote in an email.

The current rule was finalized during the Biden administration after decades of pleading from federal health researchers and miner advocates. It lowered legal exposure limits for coal workers, extended protections to sand and gravel quarries, and required baseline medical testing for new miners to establish whether they were being harmed by silica dust inhalation.

However, before those stricter standards could be enforced, mining industry associations sued, representing industries like kitty litter and gravel quarries, claiming the requirements would be costly and cause "irreparable harm." A federal judge's injunction and a voluntary enforcement pause meant the stricter protections never fully took effect. In court documents, MSHA said the proposed rule may resolve some of the issues raised in the lawsuit. For example, the proposal exempts sorptive mineral mines like kitty litter and oil absorbents from silica dust requirements altogether.

The public can comment online for 60 days once the rule is published or attend a virtual hearing on Dec. 15 to give MSHA feedback.