The Department of Labor’s Office of Inspector General (OIG) published its audit report of the Mine Safety and Health Administration’s (MSHA) silica enforcement program in coal mines. The report stated that OIG conducted the audit because stakeholders have raised concerns about exposures to respirable crystalline silica in coal mines (RCS) for four decades.

The report recognizes the value of the reduced coal dust standard and industry’s use of the continuous personal dust monitor (CPDM) mandated in the 2014 Dust Rule to control respirable dust in the coal mine environment. The OIG report also focuses on what it says MSHA has not done, including a lower silica level to match other governmental regulations, such as the RCS permissible exposure limit (PEL) from the Occupational Safety and Health Administration (OSHA), and adoption of recommendations from the National Institute of Occupational Safety and Health (NIOSH) and its Mine Safety and Health Research Advisory Committee.

The audit also stated that the agency’s coal dust sampling protocol may not be sufficiently frequent to protect miners’ health. In the final analysis, though, OIG noted that there needs to be a separate silica standard because MSHA cites coal operators for overexposures to the coal dust standard, and not for excessive RCS.

The audit makes three recommendations to MSHA: Adopt a lower RCS exposure limit in coal mines based on recent scientific evidence; establish a separate RCS standard so MSHA can issue citations and penalties for non-compliance; and increase sampling frequency for inspector-collected samples where needed.

The Office of the Assistant Secretary did not agree with recommendations one and two and stated that MSHA will issue a proposed rule but could not presume its substance, including a lower PEL for RCS.

For recommendation three, MSHA said it will begin a study to determine if increased inspector sampling is needed.