Interlaboratory Study of K Factor Determination by Asbestos-Analysis Laboratories

Abstract

The National Voluntary Laboratory Accreditation Program (NVLAP) of the National Institute of Standards and Technology (NIST) has been accrediting laboratories for the analysis of asbestos by transmission electron microscopy since 1990. As part of the quality assurance procedures for the program, laboratories are required to determine k factors for Na, Mg, Si, Al, Ca and Fe. An interlaboratory study has been conducted by NIST and the Research Triangle Institute (RTI) in which laboratories analyzed thin film standards SRM 2063 or SRM 2063a. This work reports results of initial analysis of the data.