Differentiating Amphibole Asbestos from Non-Asbestos in a Complex Mineral Environment

Abstract

Extending the TEM methods designed for the evaluation of atmospheres in which any primary mineral fibers present are derived from a commercial asbestos fiber is a challenging task. This is because the methods employed leave it to the expertise of the user to identify and evaluate interferences. Improper analysis of nonconstruction materials for asbestos content often results in the misidentification of non-asbestos amphibole particles as asbestos fibers. These errors have received widespread publicity in the media (such as the asbestos-in-crayons story) and have caused unwarranted reformulation of harmless products. The primary cause of these errors has been a poor understanding of mineralogy and analytical techniques among the many asbestos laboratories that arose following the passage of the 'Asbestos Hazardous Emergency Response Act' (AHERA) regulations. This study outlines a procedure based on published data that can be used to correctly classify a microscopic, elongated particle as either asbestos or non-asbestos.

Asbestos in commercial cosmetic talcum powder as a cause of mesothelioma in women

“…The scientific community has not generally adopted cleavage fragment differentiation criteria. 46 It is unclear how to identify a cleavage fragment once the stone or material has been finely ground. Two criteria for distinguishing cleavage fragments from asbestos fibers have been proposed.…”

“…van Orden et al propose criteria to identify cleavage fragments by SEM. 46 The criteria are based on surface contours which identify a cleavage fragment. 46 However, this method has not been verified and is not generally accepted.…”

“…46 The criteria are based on surface contours which identify a cleavage fragment. 46 However, this method has not been verified and is not generally accepted. There were no photographs of TEM or high-resolution highmagnification SEM provided by Laboratory D, which classified potential asbestos fibers as cleavage fragments In conclusion, we found that a specific brand of talcum powder contained identifiable asbestos fibers with the potential to be released into the air and inhaled during normal personal talcum powder application.…”

Methodologies for Determining the Sources, Characteristics, Distribution, and Abundance of Asbestiform and Nonasbestiform Amphibole and Serpentine in Ambient Air and Water

“…Elongated serpentine fragments tend to be less regularly prismatic, although they can meet criteria for EMP (Wylie and Bailey, 1992). The differences in dimensional characteristics of asbestos relative to cleavage fragments have been used to discriminate these populations (Siegrist and Wylie, 1980;Virta et al, 1983;Wylie et al, 1985;Van Orden et al, 2008;Chatfield, 2013;Harper et al, 2012). These methods were developed from studies of populations that contain a large number of particles with lengths that extend over several orders of magnitude, and the problem of consistently identifying a single particle as a fiber or fragment is unresolved.…”

Asbestos in commercial cosmetic talcum powder as a cause of mesothelioma in women

“…16 The authors cite a lack of accepted procedures for identifying asbestos fibers from nonasbestos fragments by electron microscopy. In fact, a review of the literature, including Van Orden et al 12 and Wylie, 16 shows that there are well-defined characteristics of asbestos that differentiate it from the nonasbestos mineral fragments in the TEM. The authors claim that Van Orden's method is a scanning electron microscopy (SEM) method that was not validated for the purpose of distinguishing between asbestiform and cleavage populations.…”