The existing toxicology literature on ultrafine particles and engineered nanomaterials suggest that nanomaterials may pose a threat to human health and the environment. A major challenge for the companies that produce and use these materials and for regulatory agencies is the issue of how to manage the risks of these materials while simultaneously leveraging the technological advantages that they offer over conventional materials. A major source of uncertainty in this field is created by the substantial gaps in our understanding about how the chemical, physical, and materials properties of nanomaterials correlate with their fate and transport in the environment and their biological activity. A major goal of the UC Center for Environmental Implications of Nanotechnology is to engage in highly interdisciplinary research to minimize these gaps and the corresponding uncertainty. In this talk, unique opportunities for synergism between developing environmentally-safe design principles and driving medical and environmental applications of nanotechnology will be discussed. In addition, steps that can be taken at both the state and national level to minimize risk while the field of “predictive nanotoxicology” is being developed will be presented. By way of example, a review of the California Department of Toxic Substances Control’s mandatory call in for information from manufacturers of carbon nanotubes will be presented and placed in the context of how we as a country might move forward in the near term to effectively regulation of nanomaterials.