Standard Test Method for Turner and Newall (T and N) Wet-Length Classification of Asbestos
|Publication Date:||1 June 2004|
This test method covers the operation of the Turner and Newall (T and N) wet sieving classifier for asbestos,(Footnote 2) and a procedure for the determination of fiber length distribution and fines (defined in Terminology D 2946) content of milled asbestos fiber (−74 µm (200 mesh)) sieve described in Specification E 11.
For purposes of estimating length distribution, the test is limited to samples free from excessive quantities of non-fibrous particles or contaminants. Quantities exceeding 0.05 g retained in any given length fractions are considered excessive.
For comparisons between different fiber grades, only those specimens which have approximately the same degree of fiberization as determined by Test Methods D 2752 will give completely meaningful results.
This test method is not applicable to ultrafine grades of asbestos powders which contain little or no fibers retained on a 74-µm (200 mesh) sieve. This method is restricted to Quebec Standard(Footnote 3) grades 4A to 7D inclusive as determined by Test Method D 3639.
NOTE 1 - This is an alternative procedure to Test Method D 2589.
The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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."(Footnote 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. For a specific hazard statement, see 1.6.
Footnote 2 - The apparatus is supplied, on a non-profit basis, as a service to the asbestos industry by TAF International, Bowdon House, Ashburton Rd. W, Trafford Park, Manchester M170RQ, England.
Footnote 3 - Available from the Asbestos Institute, 1300 Sherbrooke St. West, Suite 412, Montreal QC, Canada H3A 2M8.
Footnote 4 - Available from The Asbestos Institute,