Home 5 ERASM Research 5 Freshwater environment 5 Ecotoxicity testing 5 Geography-referenced regional exposure assessment tool for European rivers (GREAT-ER)

Geography-referenced regional exposure assessment tool for European rivers (GREAT-ER)


GREAT-ER is a geo-referenced exposure model developed to predict environmental concentrations of down-the-drain chemicals in the freshwater environment. ERASM sponsored research to evaluate the predictive power of the GREAT-ER model. A project located in Spain (river Llobregat), reflecting a dry scenario, was complemented by research conducted in the UK. Overall the results reveal that GREAT-ER can be applied for different hydrological regimes as they are typical for European rivers.


Within the environmental risk assessment that constitutes a pivotal element of the chemical legislation (e.g. REACH – Registration, Evaluation, Authorisation and Restriction of Chemicals – Regulation (EC) No 1907/2006), the determination of the predicted environmental concentration [PEC] plays a key role. The GREAT-ER model is mentioned in the REACH Technical Guidance Document as a potential higher-tier exposure model.

Outcome of research

The GREAT-ER project fostered the development of a new methodology to predict environmental concentrations for specific locations mainly for down-the-drain-chemicals with wide dispersive use (e.g. surfactants). Since GREAT-ER is geography referenced, the model allows the prediction of areas where concentrations might be considerably higher than on average (so-called “hot spots”). Hence, results from GREAT-ER simulation runs can be used for the planning of monitoring programs.

Computer fate models are also capable of predicting the concentration of new chemicals that have not entered the aquatic environment yet.

More than 100 scientific papers reference the use of GREAT-ER for chemical exposure assessment. While GREAT-ER has been selectively used in academic research and environmental risk assessment of pharmaceuticals, no widespread use in environmental risk assessment of industrial chemicals under REACH has been observed so far. The GREAT-ER project exemplifies the spirit of innovation within our industry and illustrates how advanced scientific research can be applied to address issues emerging from legislation.