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Environmental fate & pathways

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The biodegradability of the test substance was investigated in accordance to EU Method C.4-D (Kanne, 1993). In accordance to internationally accepted criteria of the OECD, the test substance is considered as "readily biodegradable" since it attained 81 % degradation after 28 days

Brorson et al. (1994) identified the test substance as not persistent in the environment according to the "ultimate" aerobic biodegradability test ISO 7827. 68 % degradation has had occurred after an exposure time of 28 days for 4-phenylbutenone. No investigations concerning biodegradation in water and sediment (simulation tests) and soil are intended based on exposure considerations. Furthermore, the substance is not persistent in the environment, which is shown by the Ultimate and Primary Biodegradation Timeframe of the mentioned QSAR prediction (weeks / days-weeks) as well as supporting data according to ISO 7827 and OECD 301C. In accordance with REACH, Annex IX, Section, column 2, no further testing is triggered.

Furthermore, the biodegradability to the test substance was predicted with the help of the scientifically accepted calculation program BIOWIN v4.10 (EPIWIN software) by US-EPA, including seven different prediction models (Biowin 1 - 7) (Chemservice S.A., 2011). According to the Linear Model as well as the Non-Linear Model, the substance is biodegrading fast. The Ultimate Biodegradation Timeframe is "weeks", and the Primary Biodegradation Timeframe reveals "days-weeks". Both MITI Models predict that the substance is not readily biodegradable, which is also the overall prediction result. Under anaerobic conditions, the test substance will not biodegrade fast.