Risk management of nanotechnology is challenged by the enormous uncertainties about the risks, benefits, properties, and future direction of nanotechnology applications. Because of these uncertainties, traditional risk management principles such as acceptable risk, cost–benefit analysis, and feasibility are unworkable, as is the newest risk management principle, the precautionary principle. Yet, simply waiting for these uncertainties to be resolved before undertaking risk management efforts would not be prudent, in part because of the growing public concerns about nanotechnology driven by risk perception (...) heuristics such as affect and availability. A more reflexive, incremental, and cooperative risk management approach is required, which not only will help manage emerging risks from nanotechnology applications, but will also create a new risk management model for managing future emerging technologies. (shrink)