Preventing Silicosis & Deaths in Construction Workers – 3
CURRENT EXPOSURE LIMITS
The current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for respirable dust containing crystalline silica (quartz) for the construction industry is measured by millions of particles per cubic foot (mppcf) and is calculated using the following formula
[29 CFR*1926.55]:
250 mppcf
PEL† = ___________
% silica +5
*Code of Federal Regulations. See CFR in references.
†8-hour time-weighted average (TWA).
The current OSHA PEL for respirable dust containing crystalline silica (quartz) for general industry is as follows [29 CFR 1910.1000]:
10 mg/m3 250 mppcf
PEL = ___________ or ___________
% silica +2 % silica +5
For more information on OSHA, please visit their website.
The National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit (REL) for respirable crystalline silica is 0.05
mg/m3 (50 µg/m3) as a TWA for up to 10 hours/day during a 40-hour workweek [NIOSH 1974].
For more information on NIOSH, please visit their website.
