ASTM D4198-82(2011)

These test methods are appropriate for qualifying absorbent pads used with membrane filters for bacteriological enumeration.

The test methods described are applicable to quality control testing of absorbent pads by the suppliers and users of these pads and to specification testing of absorbent pads intended for use with membrane filters in bacteriological enumeration.

Other pure culture organisms and their appropriate culture medium may be substituted for the E. coli and M-FC media for specification testing, as required.

1.1 These test methods cover the determination of the nutrient-holding capacity and the toxic or nutritive effect on bacterial growth of organisms retained on a membrane filter, when the absorbent pad being tested is used as a nutrient reservoir and medium supply source for the retained bacteria.

1.2 The tests described are conducted on 47-mm diameter disks, although other size disks may be employed for bacterial culture techniques.

1.3 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.