Quality audit samples and the asbestos analyst registry.
Appl Ind Hyg 1988 Jun; 3(6):R4-R5
The method used by the quality audit program for asbestos counters (the Asbestos Analyst Registry (AAR)) to assess counter performance was described. Asbestos quality audit samples consisted of chrysotile (12001295) asbestos and some particulate matter on filters. Filters were 25 millimeter mixed cellulose ester filters in cassettes; aerosol asbestos was generated by a fluidized bed of bronze powder mixed with chrysotile and collected in a large sampling chamber. AAR counters received four filter samples for analysis quarterly; asbestos concentration ranged from 100 to 1300 fibers per cubic millimeter. Results reported by AAR counters were compared to AAR performance limits determined by the method developed in the United Kingdom Regular Interlaboratory Counting Exchanges program; results were rated as acceptable or outliers. AAR counters with no more than two outlier results over two successive rounds were rated acceptable in overall performance. Results of AAR participants tended to cluster about the reference value determined by automated fiber counts by Magiscan image analysis; retests provided a method for participants with unacceptable results to demonstrate resolution of their problems. The author concludes that the AAR is a successful quality assurance program for asbestos counters.
NIOSH-Author; Asbestos-dust; Airborne-particles; Aerosol-sampling; Analytical-methods; Industrial-hygiene-programs; Industrial-hygiene; Quality-control
Applied Industrial Hygiene