WASHINGTON — Two days before his term ended, a member of the independent federal commission overseeing mine safety accused the Trump administration of an "unlawful" action that he warned could endanger the "lives of the nation's miners."

Robert F. Cohen, whose term expired last month on the mine safety and health panel after he served under both Presidents George W. Bush and Barack Obama, alleged in a scathing dissent that Labor Secretary Alexander Acosta had undertaken an illegal move cutting back on a worker safety rule that threatens to undermine the "most powerful tool for protecting the lives of the nation's miners."

Cohen's criticism was in response to the Trump administration easing enforcement of a key worker safety rule against a West Virginia coal mine, despite finding "significant and substantial" violations at the facility.

Robert F. Cohen Jr Federal Mine Safety and Health Review Commission

The Department of Labor determined that Pocahontas Coal Company’s Affinity Mine would no longer be subject to tough enforcement actions taken against mines that repeatedly violate mine health and safety laws and receive a "pattern of violations" notice.

Cohen blasted the administration for a "corrupted reading" of the law. "As an independent agency charged with reviewing enforcement actions brought by the Secretary, this Commission should not assent to such an illegal act," wrote Cohen, whose term on the Federal Mine Safety and Health Review Commission ended on Aug. 30.

Cohen said there was no evidence that the Pocahontas facility had a clean record as federal law requires for a mine to have its pattern-of-violation designation removed, making the Labor Department's decision "legally unsupportable." He also said the coal company and the administration "attempted to shield their actions from the public by initially filing pleadings for us in secret."

"Abandoning the (pattern of violation) regulation's strict application sends the dangerous message that an operator who has chronically disregarded safety, thus gaining an unfair advantage over safer competitors in the process, may nevertheless obtain reprieve from the Mine Act's heaviest sanctions by the grace of a friendly administration no longer committed to enforcing these sanctions,” he continued.

"That message endangers miners," added Cohen, who wrote his letter on Aug. 28, the same day the Labor Department changed the Pocahontas mine's safety designation.

Cohen was first appointed to the commission by Bush and was reappointed under Obama, previously working as an attorney representing mine workers.

Coal mines that receive the pattern-of-violations designation are subject to stringent oversight and enforcement actions until they complete a health and safety inspection without receiving any citations classified as "significant and substantial" violations of the law. The Pocahontas mine continued to receive such citations during federal inspections, both before and after the Labor Department lifted its designation as a serial offender on Aug. 28, according to public records.

The Obama administration strengthened the pattern of violation rule in 2013 after the Upper Big Branch disaster killed 29 West Virginia workers in a mine with a long track record of serious safety violations. David Zatezalo, Trump’s mine safety and health chief, faced sharp questioning during his Senate confirmation for running a coal company that received two pattern-of-violation notices under his watch.

The Department of Labor did not respond to a request for comment.

On Sept. 5, shortly after the administration lifted the pattern of violation designation, the Pocahontas mine received a citation for failing to protect workers from hazards related to falling "roof, face and ribs."

It was one of the key hazards that federal officials had cited when it decided in 2013 to subject the mine to tougher enforcement actions, which require workers to be withdrawn from areas where new violations are found. Affinity Mine has received a total of 17 significant and substantial citations since the beginning of July, according to public records.

United Coal Company, which operates the Pocahontas mines, defended Affinity Mine’s safety record, saying that the rate of serious citations "has improved dramatically since 2013."

"United Coal Company and their operating subsidiaries view safety as their most important value," said Paul Konstanty, the company’s vice-president and general counsel. "Affinity Coal Company and its management team have put policies and practices in place to ensure that it complies with Federal and State law, and is the safest mine it can be."

The "significant and substantial" classification for violations "can be misleading," Konstanty added. "The issuance of ‘S&S’ citations does not mean that an accident or injury is probable, or even more likely than not to occur. For example, on a surface mine operation, the failure to wear a seat belt in a vehicle is an ‘S&S’ violation."

In exchange for the changed designation, the Pocahontas Coal Company agreed to drop its legal proceedings against the administration that contested its original pattern of violation notice, Cohen said. In its 2013 decision to take action against the mine, the Obama administration cited the deaths of two miners at the Pocahontas’s Affinity Mine during its review period, as well as a significant number of incidents that involved "high negligence or reckless disregard for the health and safety of miners."

"If this is unraveled some mines may again go back to ignoring conditions that can lead to disasters and deaths," said Joe Main, Obama's former head of mine safety.

Main led efforts to strengthen the pattern of violation rules, pointing out that serious violations dropped significantly after the 2013 reforms. The Trump administration is currently negotiating a settlement with the Ohio Coal Association and Murray Energy, which sued to stop the rules.

Worker advocates say they are highly concerned about the Labor Department's decision.

"'Significant and substantial’ violations are referred to that way for a reason — people die, people lose limbs," says Phil Smith of the United Mine Workers of America, which sent a letter to the Labor Department questioning the decision to change its safety designation. "Every mine safety law on the books is written in a miner’s blood."

"President Trump has already put his disregard for coal worker safety into action by refusing to enforce the rule against a West Virginia mine operator repeatedly cited for endangering mine worker safety," said Charisma Troiano, press secretary for Democracy Forward, a liberal advocacy group in Washington. "Not only are President Trump’s broken promises on worker protections potentially unlawful, they could have dangerous and deadly results."

Marco Rajkovich, Trump's nominee to chair the mine safety review commission, has a long history of defending coal companies that have committed safety violations. He is still awaiting Senate confirmation.

CLARIFICATION (Sept. 18, 2018, 12:46 p.m. ET): An earlier version of the article stated that Robert Cohen was appointed by President Barack Obama to a federal mine safety commission, which occurred in 2012. The article has been amended to note that Cohen was first appointed to the board by President George W. Bush.