The rate of water absorption is an extremely important property of most sanitary products such as paper toweling and tissues.

1.1 This test method covers the determination of the rate at which an unsized and absorbent paper will absorb water by measuring the time required for the paper to absorb completely a specified quantity of water (1-4).

Note 1—This test method is related to TAPPI T 432 om-82, with which it is technically identical.

1.2 This test method is not intended for sized papers or those having an absorption time of over 120 s. Such papers should be tested in accordance with Test Method D 779 or ISO 535.

1.3 For ink absorption of blotting paper, see Test Method D 2177.

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.