title: The time-window--an inadequate criterion for the ready biodegradability assessment of technical surfactants.
abstract: The attainment of the biodegradation pass-level within a distinct time period (10 days after the end of the lag-phase) is one of the criteria for assessing the ready biodegradability of chemical substances. The time-window as a simple approach for describing biodegradation kinetics is a poor descriptor in the case of mixtures and poorly soluble compounds. Technically used surfactants are a mixture of numerous homologues and isomers and many are composed of two organic moieties which will be degraded sequentially. The associated problems in fulfilling the time-window requirement and the inadequacy of this criterion for the ready biodegradability assessment of surfactants are illustrated and discussed.
authors.affiliation: Henkel KGaA, Düsseldorf, Germany. josef.steber@henkel.de
authors.forename: K
authors.initials: K
authors.lastname: Richterich
authors.forename: J
authors.initials: J
authors.lastname: Steber
mesh_terms: D001673:Biodegradation, Environmental; D007536:Isomerism; D007700:Kinetics; D008962:Models, Theoretical; D009930:Organic Chemicals; D018570:Risk Assessment; D013501:Surface-Active Agents / Q000378:metabolism*
chemical_list: D009930:Organic Chemicals; D013501:Surface-Active Agents