Respiratory Protection Recommendations for Airborne Exposures to Crystalline Silica

This document describes the NIOSH policy for respiratory protection against airborne exposures to crystalline silica. NIOSH recommends the use of half-facepiece particulate respirators with N95 or better filters for airborne exposures to crystalline silica at concentrations less than or equal to 0.5 milligrams per cubic meter of air (mg/m³). The Occupational Safety and Health Administration (OSHA) also specifies the use of at least a 95-rated filter efficiency [29 Code of Federal Regulations (CFR) 1910.134]. The recommendation for a 95-rated filter efficiency reflects the improved filter efficiency of N95 filters over the earlier dust and mist (DM) filters.