Respirable quartz: Geometric mean exposures by state, OSHA samples, 1979–1999
PEL - permissible exposure limitREL - recommended exposure limitmg/m3 - milligrams per cubic meter
Note: Before March 1, 1989 and after March 22, 1993, the OSHA PEL is [(10 mg/m3) /(% quartz + 2)] for respirable dust containing at least 1 percent quartz. From March 1, 1989 to March 22, 1993, the OSHA PEL was 0.1 mg/m3 for respirable quartz. The NIOSH REL is 0.05 mg/m3. See appendices for source description, methods, and agents.
Source: Occupational Safety and Health Administration (OSHA) Integrated Management Information System.
