The Mine Safety and Health Administration has announced that 99 percent of the coal mine dust samples collected from April 1, 2016, through June 30, 2016, were in compliance with its coal mine dust standards requiring lower levels of dust. It said that this proves the “significantly positive impact” of its coal dust sampling rule, published in 2014.

The rule lowers the amount of permissible coal dust over a two-year period and requires the use of new technology. It also requires operators to take immediate corrective action when a sample meets or exceeds the exposure limit. The final phase of the rule, which began on August 1, 2016, lowers the respirable dust limit from 2.0 mg per cubic meter of air to 1.5 mg per cubic meter of air.

“These positive results are due to the extraordinary efforts of MSHA and industry working to clean up the air that miners breathe and successfully implement the critical respirable dust rule to protect miners from [the black lung] disease that has claimed tens of thousands of lives,” MSHA chief Joseph A. Main said.

According to the agency, the new rule “closed many loopholes in the dust-sampling program” that “had left miners exposed to” unhealthy dusts. The rule also included provisions for sampling frequency and the use of a new sampling device.

MSHA stated in a press release:

For the recent sampling, the agency analyzed more than 20,000 underground coal mine operator samples using the new, cutting edge Continuous Personal Dust Monitor that provides miners with dust results in real time during the working shift. About 99 percent were in compliance. These results correspond to the respirable dust samples collected from Aug. 1, 2014, through Jan. 2016, during Phase I, when 87,000 dust samples were collected from surface and underground coal mines by MSHA and coal mine operators. Nearly 99 percent of those samples met the dust concentration limit.