A wide range of toxicity lest methods is used or is being developed for ass
essing the impact of endocrine-active compounds (EACs) on human hearth. Int
erpretation of these data and their quantitative use in human and ecologic
risk assessment will be enhanced by the availability of mechanistically bas
ed dose-response (MBDR) models to assist tow-dose, interspecies, and in vit
ro to in vivo extrapolations. A quantitative dose-response modeling work gr
oup examined the state of the art for developing MBDR models for EACs and t
he near-term needs to develop, validate, and apply these models for risk as
sessments. Major aspects of this report relate to current status of these m
odels, the objectives/goals in MBDR model development for EACs, low-dose ex
trapolation issues, regulatory inertia impeding acceptance of these approac
hes, and resource/data needs to accelerate model development and model acce
ptance by the research and the regulatory community.