EU Directive 396/2005 states that methods are needed to account for cumulative and aggregate exposure in pesticides regulation . 27% of food samples had multiple residues in the 2006 EU residue monitoring report. The Eurobarometer shows pesticides are one of the principal worries of EU consumers regarding food safety. Industry needs clear criteria to decide on large investments in product development. The central aim of the ACROPLIS project is: to develop a framework for cumulative and aggregate risk assessment of pesticides in an understandable way, accessible for all actors involved in European risk assessment and management. ACROPOLIS will: 1) study the data needs, data availability and uncertainties for cumulative exposure and effect assessment in a probabilistic risk assessment framework; 2) integrate models describing various routes of exposure into an aggregate exposure model; 3) develop new toxicological approaches for identifying possible additive or synergistic effects and developing a strategy for refinement of cumulative assessment groups; 4) integrate cumulative and aggregate risk models including uncertainty analyses in a web-based tool, including accessible data for all stakeholders; 5) improve risk assessment strategies in Europe by analysing stakeholders attitudes, by training and by discussing the new methodology in several stakeholder conferences. The project brings together the key experts and models in Europe including dietary exposure MCRA, dermal and inhalation exposure ConsExpo, user exposure EUROPOEM and UK POEM, dose-response PROAST and risk characterisation IPRA. The new integrated model will be tested in case studies with conazoles and pyrethroids and validated with biomarker and duplicate diet studies. The model software will be tested in different countries to ensure its usability at the international level. Overall ACROPOLIS will advance the scientific foundation to meet policy needs, protect EU consumers and address their concerns.