By Timothy Cama - 08/01/14 04:08 PM EDT
New rules aimed at limiting miners’ exposure to coal dust rules by improving air monitoring took effect Friday.
The Mine Safety and Health Administration, a unit of the Labor Department, finalized the new rules in April after years of controversy and debate over restricting the standards that had not been changed in decades.
Under the new standards, mine operators will have to more thoroughly check for dust before shifts and take immediate action if levels are too high, and will be prohibited from using sample averages across time.
Air sampling is now required for full shifts when mines are at 80 percent capacity and sampling technicians must be recertified every three years.
The April rule also cut the maximum dust exposure level for miners by 25 percent. But that provision does not take effect until 2016.
The regulations are meant to help prevent black lung disease, an ailment caused by coal dust that has killed thousands of miners.
Coal mining company Murray Energy sued the Labor Department shortly after the rule came out to challenge it.