A FIELD COMPARISON OF RESPIRABLE DUST SAMPLERS

A study evaluated differences between respirable dust concentration me asured with three currently available cyclone samplers in a field sett ing. Comparisons also were made between cyclone and personal cascade i mpactor results. The cyclones selected were designed for sampling acco rding to one of three respirable dust criteria: British Medical Resear ch Council (BMRC) (D50 = 5 mum), previous American Conference of Gover nmental Industrial Hygienists (ACGIH) (D50 = 3.5 mum), and proposed AC GIH (D50 = 4 mum). Samples were collected by placing two each of three brands of cyclone, two personal cascade impactors, and two total dust samplers on a tripod-mounted boom assembly. The apparatus sampled abr asive blasting operations. A significant difference was detected betwe en the results of the BMRC and proposed ACGIH-type samplers and betwee n the BMRC and previous ACGIH-type samplers. The BMRC-type sampler con sistently yielded the highest average respirable dust concentrations, followed by the proposed ACGIH and previous ACGIH-type samplers. Casca de impactor results were converted to respirable dust concentrations u sing the appropriate collection efficiencies for comparison to cyclone results. The differences between the cyclone and cascade impactor res ults were not statistically significant at the 5% level. Results reite rate that important differences exist between respirable dust sampling methods, and that when sample results are reported, the type of sampl er used, the flow rate, and the respirable criteria with which the sam pler was designed to conform should be specified.