NIOSH Recommends Minimum Airborne Silica Exposure Level for Respirator Use

Mirrors OSHA PEL.

In a recent policy statement, NIOSH stated that workers exposed to airborne crystalline silica at concentrations no higher than 0.5 milligrams per cubic meter of air should wear half-facepiece respirators with filter ratings of at least N95. NIOSH indicates that this change in their former policy reflects the improved filter efficiency of N95 filters over earlier dust and mist filters.

This new recommendation also mirrors OSHA's requirement for exposure to crystalline silica. OSHA's general industry permissible exposure limit for crystalline silica is based on the formula: 10 milligrams per cubic meter of air divided by two plus the percentage of respirable quartz. Filters ratings of N95 meet this requirement.

For further information: http://www.cdc.gov/niosh/docs/2008-140/