A quick screening test is described for spot checking of asbestos (1332214) in bulk samples. When the presence of acoustical plaster or other calcium containing materials is suspected, a magnesium reagent containing p-nitrophenylazo-alpha-naphthol is added. If a blue color develops the sample is washed with glycerin. The glycerin washed sample is again tested with magnesium reagent. If a blue color develops, chrysotile (12001295) may be present and samples should be sent to a laboratory for confirmation of results. If the test is negative the sample must be tested for iron released from amosite (12172735) and crocidolite (1332214). The sample is reacted with iron reagent containing phenanthroline. If a red color develops the sample is washed with a acetic and sulfuric-acid mixture. After washing, hydrogen-fluoride and iron reagent are added. Development of a red color indicates the presence of amosite or crocidolite. Samples are identified by transmission electron microscopy to confirm results. Of 174 samples tested without the acid wash steps, 126 were correctly identified as positive or negative. There were 48 false positive tests and no false negatives. With the addition of the acid wash steps, false positives were completely eliminated. The authors recommend the use of this screening test for compliance with the Environmental Protection Agency's lower limit of 1 percent asbestos in bulk material.
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