Progress in the field of nanomaterials will lead to innovations in areas as diverse as health care and energy production. Based on much smaller particles than conventional materials, nanomaterials have radically different chemical, physical and bioactive characteristics. However, little is known about the health and environmental impacts of these materials, which can pass through body barriers. An EU-funded project, 'European network on the health and environmental impact of nanomaterials' (NANOIMPACTNET), brought together researchers from different disciplines to create a scientific basis to ensure the safe and responsible development of engineered nanoparticles and the materials and products based on them. The network helped to define the basis for regulations and legislation to cover the sector. The project, which ran from 2008 to 2012, involved 24 leading research institutions from across Europe and over 3 500 individuals. Work was separated into a number of areas. These covered human hazards and exposures, hazards of nanomaterials for the environment, methods for impact assessment and naming conventions. NANOIMPACTNET created a uniform platform to integrate existing and ongoing work looking at the risks of nanomaterials — initiatives that often took place in isolation from one another. Through networking activities and events, the project has created much greater collaboration in this field and opened up the way for a unified framework to assess the hazards and impacts of nanomaterials. Its work should lead to greater protection of the public and ensure the safety of products.