Nanomaterials are present in almost any industrial sector and addressed in corresponding legislation. The EC has developed a recommendation of the term nanomaterial for regulatory purposes. Due to uncertainties regarding the safety of nanomaterials, it is necessary to develop best practices and facilitate harmonization of assessment practices. However, more research with specific relevance for regulatory questions is still needed, in particular regarding the implementation of the definition of nanomaterials, the enforcement of product labeling, the development of methods for safety testing and risk assessment, and a better availability of quality data on nanomaterials for regulatory purposes. Keywords: Nanomaterials, Nanotechnology, Risk assessment, Safety testing