【国外标准】 Standard Test Method for McNett Wet Classification of Dual Asbestos Fiber (Withdrawn 2022)

4.1 Normally, results obtained by this test method are reproducible under comparable laboratory conditions. However, it must not be expected that results obtained by different operators at various laboratories and times will be in exact agreement due to some seemingly minor procedural change. Moreover, results for longer fiber grades are influenced to a greater extent by differences in fiber length distribution and characteristics than those of shorter grades.1.1 This test method covers the determination of the length distribution and fines content of milled asbestos fiber by wet classification employing the McNett fiber classifier.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 chrysotile asbestos, refer to “Safe Use of Chrysotile: 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.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.