【国外标准】 Standard Test Method for Classification of Asbestos by Quebec Standard Test (Withdrawn 2022)

5.1 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 D2987), or both, may give erratic and false results.5.2 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 either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.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.”21.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. See for a specific hazard warning.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.