The rapid rate of discovery and development in the nanotechnology field will undoubtedlyincrease both human and environmental exposures to engineered nanomaterials. Whether theseexposures pose a significant risk remains uncertain. Despite recent collective progressthere remain gaps in our understanding of the nanomaterials physiochemical properties thatdrive or dictate biological responses. The development and implementation of rapidrelevant and efficient testing strategies to assess these emerging materials prior tolarge-scale exposures could help advance this exciting field. I present a powerfulapproach that utilizes a dynamic in vivo zebrafish embryonic assay to rapidly define thebiological responses to nanomaterial exposures. Early developmental life stages are oftenuniquely sensitive to environmental insults, due in part to the enormous changes incellular differentiation, proliferation and migration required to form the required celltypes, tissues and organs. Molecular signaling underlies all of these processes. Mosttoxic responses result from disruption of proper molecular signaling, thus, earlydevelopmental life stages are perhaps the ideal life stage to determine if nanomaterialsperturb normal biological pathways. Through automation and rapid throughput approaches, asystematic and iterative strategy has been deployed to help elucidate the nanomaterialsproperties that drive biological responses.