A blind performance audit of TEM laboratories participating in the National Voluntary Laboratory Accreditation Program
Laboratories seeking accreditation by the National Institute of Standards and Technology (NIST) National Voluntary Laboratory Accreditation Program (NVLAP) for analysis of airborne asbestos by transmission electron microscopy (TEM) must successfully participate in a proficiency testing program administered by NVLAP. That proficiency testing program has been in existence since early 1990, with two test rounds completed per year. Each previous test round has been conducted as an open test (laboratories knew that the samples they were analyzing were proficiency test samples and that their performance was being evaluated). The administration of blind rounds (in which the laboratories are unaware that a test of their capabilities is being conducted) is also an integral part of proficiency testing. Blind proficiency testing more adequately assesses a laboratory's standard work product, and measures whether or not the laboratory is meeting specified criteria for work performance.