Standard Test Method for Turner and Newall (T and N) Wet-Length Classification of Asbestos

1.1 This test method covers the operation of the Turner and Newall (T and N) wet sieving classifier for asbestos, and a procedure for the determination of fiber length distribution and fines (defined in Definitions D2946) content of milled asbestos fiber (-74 [mu]m (200 mesh)) sieve described in Specification E11.

1.2 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.

1.3 For comparisons between different fiber grades, only those specimens which have approximately the same degree of fiberization as determined by Test Methods D2752 will give completely meaningful results.

1.4 This test method is not applicable to ultrafine grades of asbestos powders which contain little or no fibers retained on a 74-[mu]m (200 mesh) sieve. This method is restricted to Quebec Standard grades 4A to 7D inclusive as determined by Method D3639.

1.5 The values stated in SI units are to be regarded as standard. The values shown in parentheses are provided for information only.

1.6 This standard does not purport to address all of the safety problems 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 Section 7.