The Quebec Standard Testing Machine classifies milled chrysotile asbestos grades according to the mass fractions retained on each screen. Specimens that are not properly conditioned prior to testing or that have excessive moisture content (above 3 % in accordance with Method D 2987), or both, may give erratic and false results.

Some amphibole asbestos fibers may be classified by this test method but a standard classification for these has not been established.

1.1 This test method covers a procedure for dry classification of chrysotile asbestos fiber by length distribution.

1.2 The values stated in inch-pound units are to be regarded as the standard. The equivalent SI units may be approximate.

1.3 Warning—Breathing of asbestos dust is hazardous. Asbestos and asbestos products present demonstrated health risks for users and for those with whom they come into contact. In addition to other precautions, when working with asbestos-cement products, minimize the dust that results. For information on the safe use of chrysoltile asbestos, refer to “Safe Use of Chrysotile Asbestos: A Manual on Preventive and Control Measures.”

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. See 1.3 for a specific hazard warning.