Asbestos Containing Materials in School Buildings: Bulk Sample Analysis Quality Assurance Program. Bulk Sample Rounds 12, 13 and Blind Round III

摘要

The report presents the results of laboratories participating in the twelveth, thirteenth and third (III) blind round of the bulk sample analysis quality assurance program sponsored by the U.S. Environmental Protection Agency. Three hundred twenty-three, 386 and 51 laboratories which analyze bulk samples (by polarized light microscopy) to determine asbestos content participated in these rounds, respectively. Laboratories received bulk samples of asbestos, asbestos substitutes or other bulk insulation materials. Three aspects of analytical results were considered: classification of a sample as either asbestos (positive) or nonasbestos (negative); identification of the specific type of asbestos present; and quantitation of the relative amount of major constituents present. A performance rating was assessed for each laboratory, based only on the ability to correctly classify samples. Reductions of a possible 4/4 correct score was made only for the reporting of false positives and false negatives. Samples were correctly classified as asbestos or non-asbestos containing materials (as described in Federal Register, Vol. 47, No. 103, Thursday, May 27, 1982) by 98.5%, 98.6% and 96.7% of the laboratories participating in rounds twelve, thirteen and third blind round, respectively.