Alcohol ethoxysulphates (AES) are a widely used class of anionic surfactants. They are used in household cleaning products, personal care products, institutional cleaners and industrial cleaning processes, and as industrial process aids in emulsion polymerisation and as additives during plastics and paint production. Uses in household cleaning products, the scope of HERA, include laundry detergents, hand dishwashing liquids, and various hard surface cleaners.
The total volume of AES surfactants used in Europe is estimated to be 276,000 tonnes/year on an active matter basis of which 108,000 tonnes/year is used in household detergents and cleaning products (CESIO, 2000).
A large environmental data set is available for AES. On the environmental fate side, this includes standard biodegradation studies, advanced simulation studies of removal in treatment systems, and field monitoring data. On the environmental effects side, acute as well as chronic single-species data are available, as well as advanced studies in micro- and mesocosm systems.
To determine the Predicted Environmental Concentration (PEC), chemical removal in wastewater treatment plants was determined from advanced simulation test data. Monitoring studies on sewage treatment plant effluents indicate that the exposure estimates in this assessment are likely to be conservative.
The Predicted No-Effect Concentration (PNEC) was based on chronic ecotoxicity data. Mesocosm studies suggest that the effects assessment based on laboratory studies is also conservative.
By means of these higher tier exposure and effects data, it could be shown that the use of AES in HERA applications (household detergents and cleaning products) results in risk characterization ratios less than one, indicating no concern, for all environmental compartments.
An additional exposure scenario was included in this risk assessment, by assuming the entire AES tonnage used in Europe is disposed of down the drain. Using the same exposure and effects assessment approach, the absence of environmental concerns can also be demonstrated for this total tonnage.