Introduction: assessing nanotechnology health and environmental risks -- Defining risk assessment and how it is used for environmental protection, and its potential role for managing nanotechnology risks -- Sustainable nanotechnology development using risk assessment and applying life cycle thinking -- The state of the science: human health, toxicology, and nano-technological risk / Brenda E. Barry -- The state of the science: environmental risks -- NANO LCRA an adaptive screening-level life cycle risk assessment framework for nanotechnology -- Alternative approaches for life cycle risk assessment for nanotechnology and comprehensive environmental assessment / Jo Anne Shatkin and J. Michael Davis -- Current and proposed approaches for managing risks in occupational environments / Brenda E. Barry -- Ongoing international efforts to address risk issues for nanotechnology.