The prime aim of the project with the full title “Risk modeling of Mixtures of endocrine disrupting chemicals relevant to human exposure, using zebrafish (Danio rerio) embryo as model organism” is development of a novel generic approach, the RiskMix strategy, to estimate the accumulated toxicity and risk of exposure to complex chemical mixtures. The approach will be based on internal exposure and dose-at-target levels, and assuming dose addition, a conservative approach that in practice avoids underestimating the risk. The RiskMix strategy will identify chemicals of concern for different population groups, as a basis for design of relevant chemical mixtures. The modeled risk estimation will be validated experimentally using adult zebrafish (ZF) and ZF embryos. Internal ZF exposure doses will be determined by chemical analysis and physiological based toxicokinetic (PBTK) modeling, allowing interspecies comparisons and extrapolations to humans. Effects on the thyroid hormone (TH) system will be in focus as a critical endocrine pathway and founded by extensive experience of the RiskMix partners from the FORMAS-funded project MiSSE. Critical are also metabolomics and gene expression studies that will be deployed in search for new biological markers of effects on the TH system.