Procedure for the Analysis of Talc for Asbestos
THE MICROSCOPE
2015, Volume 63:1, pp. 11–20
DOI
https://doi.org/10.59082/JUXB6713
AUTHOR
James R. Millette
ABSTRACT
The analysis of talc powder for asbestos is most appropriately done with a combination of polarized light microscopy (PLM), transmission electron microscopy (TEM) and in some cases a screening by X-ray diffraction (XRD). Low levels of thin asbestos fibers in talc may only be seen using the TEM analysis. Although never formally adopted by the U.S. Environmental Protection Agency (EPA), the 1993 EPA bulk method (EPA R-93) for asbestos provides the basis for the PLM portion of the method, as it is a good description of the light microscopy techniques available. The consensus method D6281 balloted and published by ASTM International provides the basis for the TEM portion of the method. The method described here has been used to investigate vintage talcum powders and talcum products currently available. Some asbestos has been found in vintage powders but with the exception of one Chinese product, asbestos was not detected in currently available powders using the talc-asbestos method described here.