Asbestos microscopy

Microscopists in every technical field use the microscope to characterize, compare, and identify a wide variety of substances, eg, protozoa, bacteria, vimses, and plant and animal tissue, as well as minerals, building materials, ceramics, metals, abrasives, pigments, foods, dmgs, explosives, fibers, hairs, and even single atoms. In addition, microscopists help to solve production and process problems, control quaUty, and handle trouble-shooting problems and customer complaints. Microscopists also do basic research in instmmentation, new techniques, specimen preparation, and appHcations of microscopy. The areas of appHcation include forensic trace evidence, contamination analysis, art conservation and authentication, and asbestos control, among others. [Pg.328]

Asbestos fiber identification can also be achieved through transmission or scanning electron microscopy (tern, sem) techniques which are especially usefiil with very short fibers, or with extremely small samples (see Microscopy). With appropriate peripheral instmmentation, these techniques can yield the elemental composition of the fibers using energy dispersive x-ray fluorescence, or the crystal stmcture from electron diffraction, selected area electron diffraction (saed). [Pg.352]

In order to define the extent of emissions from automotive brakes and clutches, a study was carried out in which specially designed wear debris collectors were built for the dmm brake, the disk brake, and the clutch of a popular U.S. vehicle (1). The vehicle was driven through various test cycles to determine the extent and type of brake emissions generated under all driving conditions. Typical original equipment and aftermarket friction materials were evaluated. Brake relines were made to simulate consumer practices. The wear debris was analyzed by a combination of optical and electron microscopy to ascertain the asbestos content and its particle size distribution. It was found that more than 99.7% of the asbestos was converted to a nonfibrous form and... [Pg.275]

Microscopy (asbestos) metal content (by atomic absorption, atomic emission, fluorescence and infra-red spectrometry)... [Pg.354]

BS ISO 10312 Asbestos Direct-transfer transmission Electron microscopy... [Pg.357]

MDHS 77 Asbestos m bulk materials - Sampling and identification by polarized light microscopy (PLMj... [Pg.582]

Asbestos by Transmission Electron Microscopy Analytical Method for the Determination of Asbestos Fibers in Water (EPA/600/4-83-043)... [Pg.223]

Asbestos by Transmission Electron Microscopy Determination of Asbestos Structures Over 10 p,m in Length in Drinking Water (EPA/600R-94/134)... [Pg.223]

Standard Methods for the Examination of Water and Wastewater 2570B Transmission Electron Microscopy (Asbestos)... [Pg.1207]

McCrone, W. (1978). Identification of asbestos by polarized light microscopy, pp. 235-248. In C. C. Graved, ed. Workshop on Asbestos. Spec. Pub. No. 506. National Bureau of Standards, Washington, DC. [Pg.157]

Asbestos can be determined by several analytical techniques, including optical microscopy, electron microscopy, X-ray diffraction (XRD), light scattering, laser microprobe mass analysis, and thermal analysis. It can also be characterized by chemical analysis of metals by atomic absorption, X-ray fluorescence, or neutron activation techniques. Electron microscopy methods are, however, commonly applied for the analysis of asbestos in environmental matrices. [Pg.283]

Air drawn through a 0.8 to 1.2 mm cellulose ester membrane filter, asbestos fibers counted by positive phase contrast microscopy technique sample prepared by acetone/triacetin method (NIOSH Method 7400, 1985). [Pg.284]

Yada, K. 1971 Study of microstructure of chrysotile asbestos by high resolution electron microscopy. Acta crystallogr. A 27, 659-664. [Pg.127]

Limit of aluminum Limit of aluminum Absence of asbestos (IR, XRPD, optical microscopy)... [Pg.231]

Applications of Optical Microscopy in Analysis of Asbestos and Quartz... [Pg.13]

Optical Microscopy is a powerful tool in industrial hygiene for the analysis of asbestos, quartz or other substances. Electron microscopy and specialized techniques in optical microscopy such as ultraviolet, infrared, and fluorescence, although important, will not be considered in this paper. [Pg.13]

Bayer, S.G., Zumwalde, R.D., Brown, T.A., "Equipment and Procedures for Mounting Mi 11ipore Filters and Counting Asbestos Fibers by Phase Contrast Microscopy", 1-15 (July, 1969), U.S. Department of Health, Education and Welfare, Public Health Service, Bureau of Occupational Safety and Health,... [Pg.39]

In 1956 McCrone founded McCrone Associates, a private analytical laboratory in which the principal analytical technique employed was polarized light spectroscopy. Over the years he and his staff learned to visually identify over 30000 particles (McLafferty 1990). McCrone Associates speciahzed in the identification of polymorphs, asbestos samples, airborne impurities, among others. McCrone recently endowed a chair of chemical microscopy to Cornell University, his Alma Mater. [Pg.26]

Units of Exposure. Consideration and comparison of quantitative data on asbestos inhalation studies are complicated by the fact that a number of different methods have been used to measure asbestos levels in air. Currently, the standard method for measuring asbestos concentrations in workplace air employs phase contrast microscopy (PCM). A particle visible under PCM is counted as a fiber if it is 5 micrometers (pm) long and has a length/thickness ratio of 3 1. However, the method cannot detect fibers thinner than about 0.3 pm and caimot distinguish between asbestos fibers and other fibers (NIOSH 1987). [Pg.41]

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