Coastal marine water area (Little Belt, Denmark) used for the site specific risk assessment
Surfactant alcohol ethoxylates, alcohol ethoxysulphates and linear alkylbenzene sulphonate are all commonly used in household detergents and fractions will inevitably end in the sea. DHI has developed a method to quantify the impact and determine the risk detergents may have on the marine environment.
The method involves exposure assessment and risk characterisation, where the assessment is conducted by calculating a Risk Characterisation Ratio (RCR) defined as the relation between the predicted environmental concentration (PEC) and the predicted no effect concentration (PNEC). The RCR is used as an indication of a possible risk.
RCR = PEC/PNEC
(A RCR <1 is indicative of no risk and a RCR > 1 indicates a risk)
The method is site specific and the predicted environmental concentration (PEC) is derived using the detailed transport and fate model ECO Lab developed by DHI.
A specific assessment has been made for the waters Lille Belt in Denmark. The results from the ECO Lab model were compared to the results obtained by applying the more traditional approach represented by EUSES, which uses the methods described in the ECHA guidance documents on exposure assessment.
Predicted no effect concentrations (PNECs) were derived from the available information on the acute and chronic aquatic toxicity of the surfactants, which includes a large number of studies.
Risk characterisation ratios were calculated for fresh water and marine water and were below 1 for all surfactants. These results indicate that there is no risk to the aquatic environment due to the applications of the surfactants alcohol ethoxylates, alcohol ethoxysulphates and linear alkylbenzene sulphonate in household detergents.
The results show that general household detergents pose no risk to the marine environment in Lille Belt, and that this method can be applied in general to determine risk.