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Occupational Safety And Health Administration Methods.
Workshop on Asbestos: Definitions and Measurement Methods, National Bureau of Standards, U.S. Department of Commerce, NBS Special Publication No. 506 1978 Nov:431-440
Methods used by OSHA for the analysis of asbestos (1332214) are described. Equipment at one laboratory is described. Phase contrast microscopes equipped with a polarizer, an analyzer, retardation plates, and rotating stage are explained. X-ray diffraction and transmission electron microscopes with energy dispersive units are also described. Routine determinations of airborne asbestos are made by the membrane filter method at a magnification of 400 to 450 times. Bulk samples are examined on a reflected light stereo microscope. Percentage of asbestos in talc (14807966) samples is determined by particle counting. Analysis of membrane samples is discussed in some detail. Optical tests for asbestos or other fibers are divided into two categories: those performed with fibers on the membrane and those performed after fibers are removed from the membrane. Polarized light, angle of extinction, retardation of color pattern, and dispersion staining are used to identify asbestos. A system for differentiating between the various asbestos fibers is discussed. Directions for the dispersion staining identification of asbestos minerals and wollastonite (13983170), a common interference, are outlined.
Safety-practices; Regulations; Air-monitoring; Fibrous-dusts; Airborne-dusts; Chemical-analysis; Air-contamination; Asbestos-dusts; Dusts; Air-sampling;
1332-21-4; 14807-96-6; 13983-17-0;
Workshop on Asbestos: Definitions and Measurement Methods, National Bureau of Standards, U.S. Department of Commerce, NBS Special Publication No. 506
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division