This test method is designed to determine whether the sulfonate tested will be removed sufficiently by usual methods of sewage treatment for the effluent to be safely discharged to the environment without further treatment.

If the surfactant reduction in the presumptive test equals or exceeds 90 %, the material is considered to be adequately biodegradable without further testing.

If the surfactant reduction in the presumptive test is between 80 and 90 %, the material should be subjected to the confirming test.

If the surfactant reduction in the presumptive test is below 80 %, the material is considered inadequately biodegradable.

If it is necessary to run the confirming test, the surfactant reduction in this test must be at least 90 % for the material to be considered adequately biodegradable.

An example of data from both the presumptive and confirming test can be found in Appendix X4.

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.