The challenges of nanotechnology risk management

•Risk assessments that includes decision analyses are important to balance risks with technological benefits and costs.•Traditional bottom-up approaches are essential to risk assessment.•Top-down approaches developed in decision analysis are necessary to risk management efforts.•Risk-benefit tradeoffs are crucial for communication and for nanomaterial design towards sustainable nanotechnology.•Advances in informatics could accelerate research and development in nanotoxicology and exposure science.