Assessment of the Potential Risk, if any, of Surfactant Chemicals to the Environment
This study carried out on behalf of the EU DGIII was designed to identify if surfactant chemicals posed a risk in surface waters, and to determine whether or not a requirement to assess the ultimate biodegradability of surfactants would be beneficial for minimising the impact of future surfactants. The study focussed on the issues surrounding persistence of surfactants and their potential for oestrogenic activity.
At the time of this report (1997) of the parent surfactants which had been tested for oestrogenicity, none have been shown to be oestrogenic. Thus, it appeared that the parent surfactants themselves did not provide cause for concern regarding the potential effects of exposure to oestrogenic chemicals. A number of breakdown products of the APEs have been shown in the scientific literature to be weakly oestrogenic in a number of assays. Both the position and branching of the alkyl group were known to affect oestrogenicity. Data obtained at the time of the study from the in vivo rainbow trout vitellogenin bioassay suggested that an oestrogenic response may be seen at concentrations of around 10 and 3 g per litre of nonyl and octylphenol, respectively. However, the importance of this in terms of health and ecology of fish populations remained uncertain.
Based on data received from AISE and CESIO during the study, the total production volume of the all surfactant chemicals which would fail the screening test is less than 100,000 tonnes per year, equated to approximately 3% of the total annual production of surfactant in detergent sold in the European Community. Analysis of standardised biodegradation data revealed that alkylphenol ethoxylates (octyl- and nonyl-), which at the time of the study (1997) had a maximum Community production volume of 50,000 tonnes per year, were the sole priority candidates for risk assessment, judged on the basis of the relative persistence and oestrogenic activity of their biodegradation intermediates.
The study concluded that in view of the biodegradability data set for surfactant chemicals, it did not appear to be advantageous to change the legislation to test the small number of chemicals, which were prioritised in this report. Alternatively, the judgement of chemical persistence and fate in the environment was assumed on the basis of a voluntary agreement between industry and representatives of the Commission, whereby chemicals could be assessed on a case by case basis by an ad-hoc committee. The basis for guidance may be readily drawn from the OECD or EC strategies for biodegradability testing was outlined in this report.