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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

The streams in this category are not considered to be readily biodegradable.

Key value for chemical safety assessment

Additional information

Data from two biodegradation screening studies are available for one member of this category, 68476 -55 -1 (ExxonMobil Biomedical Sciences Inc., 2005 and Huntingdon Life Sciences, 2004). The results from both studies indicate only a very low level of biodegradation over 28 days. However, it is difficult to assess the persistence of UVCB streams using standard test methods as the tests measure the properties of the whole substance but do not provide information on the individual constituents. Instead, it is more appropriate to consider whether the representative components of these streams are persistent.

Representative components on these streams were identified from the compositional data. The representative components were alkanes and alkenes with a carbon number between C5 to C6. The biodegradation potential of these substances was predicted by two QSAR models, Biowin and BioHCwin. None of the various representative components would be expected to be persistent.

Members of this category are therefore not considered to be readily biodegradable but their components are expected to be biodegradable on the basis of the QSAR estimates for representative components.