This paper describes a procedure to quantify emissions of chemicals for environmental protection, assessment and management purposes. The procedure uses production and use volumes from registration dossiers and combines these with Specific Environmental Release Category (spERC) data. The procedure was applied in a case study. Emission estimations were made for chemicals registered under the EU chemicals regulations for industrial chemicals (REACH) and for the active ingredients of medicines and crop protection products. Emissions themselves cannot be validated. Instead, emission estimates were followed by multimedia fate modeling and mixture toxic pressure modeling to predict environmental concentrations (PECs) and toxic pressures for a typical European water body at steady state, which were compared to other such data. The results show that screening-level assessments could be performed, and yielded estimates of emissions, PECs and mixture toxic pressures of chemicals used in Europe. Steady-state PECs agreed fairly with measured concentrations. The mixture toxic pressure at steady state suggests the presence of effects in aquatic species assemblages, whereby few compounds dominate the predicted impact. This study shows that our screening-level emission estimation procedure is sufficiently accurate and precise to serve as a basis for assessment of chemical pollution in aquatic ecosystems at the scale of river catchments. Given a recognized societal need to develop methods for realistic, cumulative exposures, the emission assessment procedure can assist the prioritization of chemicals in safety policies (such as EU-REACH), where 'possibility to be used safely' needs to be demonstrated, and environmental quality policies (such as the EU Water Framework Directive), where 'good environmental quality' needs to be reached. This article is protected by copyright. All rights reserved.