Document OEvVZn72OoBNwNN4E00L0dOzp

Aabattot can ba tctaanad quickly in !h field by two-part teat, in this teat magnesium la liberated from chryaotile, end a blue-colored complex la formed; or iron la liberated from emoalte or crocldolite. and a radcolored complex la formed. Before the acid waah atepa were added to the procedure, the preaenee or absence of abeatoa waa correctly indicated in 126 out of 174 aamplea. Forty-eight aamplee gave falaa poaldve reactions. ) but eince there were no falae negative reactions, the teat waa considered practical. After adding the acid wash steps, the chemical test correctly indicated the presence or absence of asbestos in all 41 aamplea tested. Thar* were no false positive or negative reactions. The results were verified by transmission electron microscopy, x-ray diffraction, or dispersion staining. Quick screening test for asbestos WAITER S. KIM,* JAMES W. CARTER, II* and RICHARD E. (CUPEL* "National Aeronautics and Space Administration. Lewis Research Center. Technical Services Directorate. Safety end Project Planning Office, Cleveland, OH 44135: 'Department of Health and Human Services. Public Health Service. Center for Disease Control. National Institute for Occupational Safety and Health. Division of Physical Sciences and Engineering. Measurements Suppon Branch. Cincinnati. OH 45226 8006 0471 introduction The three most common types of asbestos are chrysolite (3 Mg0 2 SiO,- 2 HjO). amosite (1.5 MgO-5.5 FeO 8 SiO.HjO), and crocidolite (NajO'3 FeOFe>Oi-8 SiOrH-O). Chrysolite accounts for a bout 90% of all asbestos processed. Amosite is used primarily for heat and pipe insulation, and crocidolite is used to make acid-resistant cement pipe and electric battery cases. Almost 3000 asbestos products are r manufactured today; the construction industry uses about two-thirds of all asbestos for soundproofing and fire proofing."' Because of the dangers to humans from asbestos and the need to be aware of its presence in any environment, the National Institute for Occupational Safety and Health (NIOSH) developed a quick and simple method for on-thespot testing for asbestos in samples of bulk material. In this test, magnesium or iron is released from asbestos and reacts with color-formingreagents to indicate the possible presence of asbestos."' The chemical test can be used directly in the field; and, if the presence of asbestos is indicated by the chemical test, sa mples should be submitted to the laboratory for more exhaustive confirmation by the use of dispersion staining, transmission electron microscopy (TEM), or equi valent methods."*4' X-ray diffraction analysis, for example, has been shown to be feasible for the detection of asbestos in bulk samples and filter samples."*4' apparatus Teflon dish or white plastic plate Plastic or glass rod Plastic squeeze bottle for quick wash-down Dropping plastic pipe! Mention of company name or product! doea not conalituta endorse ment by the National Institute for OccupationelSafetyendHealthand the National Aeronautics and Space Administration. Cwrtfu INI, Amascan its 15 mL disposable plastic beaker 25 mm size 0.8 /im mixed cellulose ester filter 25 mm size polyvinyl chloride filter 25 mm Swinnex filter holder and gasket 10 mL disposable plastic syringe reagents (reagent grade) Phosphoric Acid, concentrated 10 N sodium hydroxide Dissolve 40 g ol NaOH in 100 mL of water Mg Reagent Dissolve I mg of p-nitrophenylazo-o-naphthol in 100 mL of 2 N NaOH. Age at least a day. This reagent has a shelf life of 3 months. Hydrofluoric acid Dilute 20 mL of H F with 20 mL of water. Add 0.6 mL of concentrated HCl. Fe Reagent Dissolve 2 gof 1,10-phenanthroline in 50 mL of ethanol. This reagent is stable over 3 months. Glycerin, reagent grade Acetic acid, concentrated glacial Sulfuric acid, concentrated Double de-ionized water procedure m*gnesium test I. In those instances where the presence of acoustical plaster or other calcium-bearing materials is suspected, positive reactions will be obtained with the magnesium test. To eliminate the calcium interference, the following proce dure is used. Place a portion of the bulk sample, about the size of a large pea, in a plastic beaker. Add a few drops of '<' Myg**w tm Int Hfl Amc.Jttil Mirth. 1981 SCF-FA-7525 ' PRODUCED BY FORD