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Particulate Exposure

May 28, 2014

Airborne dusts are solids formed by processes like crushing, grinding, blasting, drilling, operating leaf blowers, and other landscaping equipment. The dust particles can be submicroscopic to visible. Dust or particulates that are not specifically listed in Table AC-1 of Cal/OSHA 5155 are regulated as “particulates not otherwise regulated” (PNOR) in Table AC-1 of Cal/OSHA 5155 with a permissible exposure limit (PEL) of 10 mg/m3 as an 8-hour TWA for total dust and 5 mg/m3 for the respirable fraction. (

Respirable sized particles can bypass the body's defense mechanism (nose hair, cilia, mucous) and are likely to be retained. The American Conference of Governmental Industrial Hygienist (ACGIH) believes that even biologically inert or insoluble particles can have adverse effects. An industrial hygiene survey can be conducted using NIOSH 0500 or OSHA PV2121. Instant readings and graphs can also be provided through the use of direct read photometers. For more information or to schedule an industrial hygiene survey please contact Johnny Lim at (858) 558-6736 or