A review of biodegradation data for specific oil field chemicals and chemical groups were performed in order to evaluate if the current categorisation of these were appropriate based on the biodegradation properties.
Data were compiled from databases like ECHA and MITI and from the literature. For compounds with limited or inconclusive test data, biodegradation was also estimated by the BIOWIN models, and the EAWAG-BBD pathway prediction system was used to predict plausible biodegradation pathways. A weight of evidence approach was used to assess the compiled information and a conclusion regarding categorisation of the single chemicals and/or chemical groups were performed whenever possible. For most compounds, no clear conclusion on the biodegradability could be drawn. Only two of the investigated compounds, benzotriazole and N-methyldiethanolamine, were assessed to very likely and likely have a biodegradability of less than 20% in seawater.