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Environmental fate & pathways

Biodegradation in water and sediment: simulation tests

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Description of key information

The aerobic biodegradation of [14C]-2,2'-dimethyl-2,2'-azodipropiononitrile has been studied in the laboratory at two concentrations (1 and 10 µg/L) in natural surface water, under dark conditions at 20 ± 2°C.

Key value for chemical safety assessment

Half-life in freshwater:
950 d
at the temperature of:
20 °C

Additional information

The aerobic biodegradation of [14C]-2,2'-dimethyl-2,2'-azodipropiononitrile has been studied in the laboratory at two concentrations (1 and 10 µg/L) in natural surface water, under dark conditions at 20 ± 2°C.

The conditions of the test, and the waters used, were suitable for studying aerobic mineralisation in water judged by the extensive mineralisation of a control reference substance, sodium [14C] benzoate within two weeks. Under these conditions, AZDN mineralised slowly with = 5% carbon dioxide formed within 60 DAT. Some degradation occurred within the water phase and at 60 DAT up to ca 11% of the applied AZDN was present as degradation products. The maximum level of any single degradation product was 6% applied radioactivity (AR). Degradation products were similar at both concentrations, but less degradation occurred at the higher concentration and very little degradation occurred in sterilised water. The DT50 for AZDN in the water, determined by SFO kinetics, was 259 days at 1 µg/L and 950 days at 10 µg/L.