Evaluating mass respirable and dust count sampling techniques.
Occup Health Saf 1979 Mar; 48(2):48-50
Thirty paired breathing zone samples were collected using commercially available sampling equipment during clay mixing operations at a small pottery operation to evaluate mass respirable and dust count techniques for an aerosol containing free crystalline silica (7631869). The first 10 sample pairs were collected during actual mixing operations, the second 10 after the aerosol cloud had dispersed for 10 minutes, and the final 10 after the cloud had settled for 20 minutes. Mean time weighted average (TWA) concentrations were calculated for respirable and total dust. Ninety nine percent of all particles sampled were in the respirable size range, and concentrations of respirable dust exceeded the threshold limit value (TLV) of 0.1 milligrams per cubic meter. Although TWA dust count concentrations exceeded the TLV of 2.72 millions of particles per cubic foot only during actual mixing operations, an overall potential hazard was suspected. The authors conclude that workers were exposed to high concentrations of free silica dust and, consequently, should use protective equipment. Respirable mass information alone may not be sufficient to assess a potential hazard, since a mass bias toward larger particles in the respiratory region may exist. Additional research is suggested to explore the bias possibility.
OHSADO; NIOSH-Publication; NIOSH-Grant; Respirable-dusts; Particle-counters; Sampling-equipment; Aerosol-mists; Respiratory-system-disorders; Personal-protective-equipment; Industrial-hazards; Pottery-products
Microbiology Colorado State University Department of Microbiology Fort Collins, Colo 80523
Occupational Health and Safety
Colorado State University, Fort Collins, Colorado