CONTAMINANT: SILICA – in Mining
ORIGIN: Mine Safety and Health Administration
REVIEWED/UPDATED: August, 2024
On April 18, 2024 the Mine Safety and Health Administration (MSHA) issued its final rule, Lowering Miners’ Exposure to Respirable Crystalline Silica and Improving Respiratory Protection.
The purpose of the Final Rule is to better protect miners by reducing occupational exposures to respirable crystalline silica, a significant health hazard, and to improve respiratory protection for miners from exposure to airborne contaminants. In addition to lowering the permissible exposure limit (PEL) and the action level for respirable crystalline silica, the rule includes provisions for methods of compliance, exposure monitoring, corrective actions, respiratory protection, medical surveillance for metal and nonmetal (MNM) mines, and recordkeeping.
MSHA’s Final Rule sets the permissible exposure limit (PEL) of respirable crystalline silica at 50 micrograms per cubic meter of air (µg/m3) for a full-shift exposure, calculated as an 8-hour time weighted average (TWA) for all mines and establishes an action level for respirable crystalline silica of 25 µg/m3 for a full-shift exposure, calculated as an 8-hour TWA for all mines. The rule also includes uniform requirements for controlling and monitoring exposures to respirable crystalline silica at coal and metal and nonmetal (MNM) mines, as well as updates to the existing respiratory protection requirements that reflect the latest advances in respiratory protection technologies and practices.
FOR THE FULL STANDARD YOU MUST REFER TO THE REGULATORY TEXT:
https://www.federalregister.gov/documents/2024/04/18/2024-06920/lowering-miners-exposure-to-respirable-crystalline-silica-and-improving-respiratory-protection.
The Final Rule incorporates by reference the voluntary consensus standard by the American Society of Testing and Materials (ASTM) – F3387-19 Standard Practice for Respiratory Protection. The Final Rule declares that, when approved respirators are used, the mine operator must have a written respiratory protection program that meets the requirements of ASTM F3387-19, including, but not limited to, the following:
- Program administration;
- Written standard operating procedures;
- Medical evaluation;
- Respirator selection;
- Training;
- Fit testing;
- Maintenance, inspection, and storage.
Refer to ASTM F3387-19 “Standard Practice for Respiratory Protection” for the entire consensus standard.
When samples indicate that a miner’s exposure exceeds the PEL, the mine operator shall make approved respirators available before the start of the next work shift. The mine operator shall provide an approved atmosphere-suppling respirator or NIOSH-approved air purifying respirator with a 100 series respirator in accordance with NIOSH standards or a particulate protection classified as a High Efficiency “HE” in accordance with NIOSH.
Moldex Solution:
Moldex offers respirators that comply with these requirements.
As laid out more fully in the Final Rule, it is the mine operator’s responsibility to identify any respirable crystalline silica hazards its employees may face and make the appropriate respiratory protection available. In addition, the Final Rule makes clear that the use of respiratory protection is to be a temporary measure while the mine operator takes corrective actions to lower the concentration of respirable crystalline silica to at or below the Permissible Exposure Limit (PEL).
Consult a mining safety professional for further guidance on compliance with the Final Rule and ASTM F3387-19.