The advances and developments achieved in nanotechnology during the last years are leading to an outstanding growth in the amount of commercial products based on engineered nanomaterials (NMs) that are currently arriving to the market. This fact is pushing EU governments and agencies to adapt their regulations on human health and environmental risk assessment of chemical substances (such as REACH) to the specific characteristics of NMs. Due to the virtually infinite number of possible combinations of chemical composition, core and surface structure, size, shape, polydispersity, etc. of NMs, its classification and regulation remains a big challenge. Several questions arise such as: How should we define NMs from a regulatory point of view? Are the existing guidelines for toxicological testing of “conventional” chemicals still valid for NMs? How should we define the dose of NM in these tests? To what extent are the current models for environmental fate and behaviour of pollutants usable for NMs? What does “NM solubility” mean? The answer to these and similar questions is still controversial, due to the structural and compositional complexity of NMs NANoREG is the first FP7 project to deliver the answers needed by regulators and legislators on Environmental Health and Safety by linking them to a scientific evaluation of data and test methods. Based on questions and requirements supplied by regulators and legislators, NANoREG will: (i) provide answers and solutions from existing data, complemented with new knowledge, (ii) Provide a tool box of relevant instruments for risk assessment, characterisation, toxicity testing and exposure measurements of NMs, (iii) develop, for the long term, new testing strategies adapted to innovation requirements, (iv) Establish a close collaboration among authorities, industry and science leading to efficient and practically applicable risk management approaches for NMs and products containing NMs.