1.1 This test method covers the determination of the degree of biodegradability of alkylbenzene sulfonates. It serves as an index of the suitability of the sulfonate for general use as a surfactant. 1.2 In general, this test method distinguishes between sulfonates in which the alkyl side chains are linear and those in which they are branched, since the former are more readily biodegradable. If the alkylbenzene sulfonate in fully formulated products is to be examined, it must be extracted using the method noted in Annex A1. (See Appendix X1 for data.) 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. Material Safety Data Sheets are available for reagents and materials. Review them for hazards prior to usage.