Classification and identification error tendencies in bulk insulation proficiency testing materials

Abstract

Since 1979, nearly 35,000 analyses of bulk insulation materials used as proficiency testing samples have been submitted to RTI by laboratories participating in the Environmental Protection Agency's Asbestos Bulk Sample Analysis Quality Assurance/Interim Accreditation Program and the U.S. Navy Asbestos Identification Proficiency Testing Program. These analyses were examined for false negative, asbestos identification, and false positive error tendencies. Conclusions drawn from the study include; a) false negative errors increased sharply as the amount of asbestos in the sample decreased, but that no relationship existed between these errors and the type(s) of asbestos in the sample; b) laboratories misidentified anthophyllite (as tremolite) and actinolite-tremolite (as anthophyllite) 7-9 times as frequently as the average for all asbestos varieties; and c) fibrous wollastonite and polyethylene produced the highest rates of false positive errors.