A rule to limit miners’ exposure to respirable coal dust – revised last in 2014 – did not establish a silica-specific standard, and the Center for Science in the Public Interest (CSPI) is out to change that.

“Until the Mine Safety and Health Administration (MSHA) sets and strictly enforces an evidence-based, silica-specific dust standard, along with improved procedures for measuring and monitoring silica, the agency will not be fulfilling its mission to ‘prevent death, illness and injury from mining and promote safe and healthful workplaces for U.S. miners,” wrote CSPI president Peter Lurie and CSPI policy associate Eva Greenthal.

The comments were filed by CSPI with MSHA in response to the agency’s final rule, Lowering Miners’ Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors (CPDMs).

CSPI urged MSHA to set a Permissible Exposure Level for respirable silica in underground coal mines of 50 ug/m³.

In a submission co-signed by adjunct professor at Harvard T.H. Chan School of Public Health Gregory Wagner and former OSHA chief David Michaels, presented an analysis of MSHA data and showed that the 2014 rule had apparently reduced silica exposure, but that hundreds of workers remain exposed to dangerous levels of silica. For example, between 2015 and 2018, 11 percent of samples from surface coal mines exceeded 50 micrograms per cubic meter (the Permissible Exposure Limit for silica established by the Occupational Safety and Health Administration) and 3 percent exceeded 100 ug/m³.