The rule, known formally as Lowering Miners’ Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors, was initially released May 1. It will be phased in over the next two years and will impact all U.S. surface and underground coal operations.

The final rule lowers miners’ exposure to coal dust, substantially increases operator sampling for respirable coal mine dust, and requires immediate corrective action when an operator’s sample shows excessive concentrations. While the frequency of sampling by MSHA inspectors does not change, the final rule authorizes MSHA to cite an operator based on a single MSHA sample showing excessive dust, rather than on an average of samples.

MSHA said that the newly effective first phase will provide immediate protection for the nation’s miners, closing loopholes it said has “masked overexposures to coal dust.”

In part, the new provisions, including compliance based on a single full-shift sample, no longer allowing samples to stop after eight hours. Additionally, immediate corrective action will now be required when a single, full-shift sample obtained by an operator where an excessive level of dust is found, and failure to take corrective action will result in a citation.

Sampling is now mandated on all shifts, and underground mine operators must collect respirable dust samples when mines are operating at 80% of production so that samples are more representative of actual working conditions.

The provisions strengthen training and certification for samplers, and for the first time the decertification process will be defined by regulation.

Under the new rules, more thorough examinations of dust controls on mining sections will be required during each shift and the number of work positions to be sampled at surface mines increases significantly.

Additionally, periodic X-rays already required for underground miners will now be extended to surface miners, along with lung function testing, occupational history and symptom assessment. The outlines transfer rights for miners with coal workers’ pneumoconiosis now also apply to surface miners.

Finally, sampling of miners with coal workers pneumoconiosis will be increased.

“August 1 marks the beginning of a healthier future for coal miners in America,” said Joseph A. Main, assistant secretary of labor for mine safety and health. “Miners can have greater confidence that the air they breathe at work will not destroy their lungs.”

According to the agency, prolonged exposure to respirable coal mine dust causes lung diseases such as coal workers’ pneumoconiosis, emphysema and progressive massive fibrosis, and National Institute for Occupational Safety and Health data has shown that more than 76,000 miners have died since 1968 as the result of the disease.