Environmental pollutants which interact with the endocrinesystem of organisms, and exert a negative impact on devel-opment and reproduction, are commonly known as endocrine disrupting chemicals (EDC). Endocrine disruption manifests inan organism or a population after sub-acute to chronic (long-term) exposure, which makes the experimental identification of hormone-active substances time- and cost-intensive. These elaborative experiments require large numbers of animals, and alternatives approaches according to the principles of the 3R(Replacement, Reduction, and Refinement) after Russell and Burch(1959), are highly desired. Shorter, life-stage confined tests weredesigned as screening tools to trigger more complex studies likea fish life cycle test, which are required to assess the endocrine disruption relevant apical endpoints. These shorter and less fish consuming predictive tests have, in principal, the potential to reduce the number of long-term apical tests. However, apical effect data from screening assays could not be used for regulatory purposes.