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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

Key value taken from published data. 
No evidence was found for significant biodegradation.

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed

Additional information

Volatility probably precludes biodegradation. It has been observed in laboratory experiments with contaminated soil-samples that CFCs are slowly biodegradable in anaerobic aquatic environments. Nevertheless, these compounds are persistent in the environment because of their chemical stability.

The “Handbook on Biodegradation and Biological Treatment of Hazardous Organic Compounds By M.H. van Agteren, Sytze Keuning, D. Janssen” states that the biological degradation of chlorofluorocarbons has not been studied extensively. In general, the order of reactivity of reactions in which the carbon-halogen bond is involved is C-I > C-Br > C-CI > C-F. Lesser halogenated aliphatics are more susceptible to hydrolysis and aerobic degradation , while higher halogenated aliphatics are more susceptible to reductive dehalogenation. Therefore, it is not surprising that the substance CFC-12 is very persistent under aerobic conditions. as has been observed in several biological studies, for example with Methylosinus trichosporium strain OB3b.