There is an urgent need for sufficient knowledge to allow reliable assessment of the risks associated with nanomaterials. The formulation of an intelligent testing strategy (ITS) that allows safety assessment across materials is required to overcome the current need of testing each nanomaterial on a case-by-case basis. By taking into consideration the research landscape, the available tools and the stakeholders involved, the ITS-NANO consortium developed a stepping-stone based research framework which can, when implemented, deliver the information required for flexible and broadly acceptable ITS and risk assessment (RA) protocols. It was identified that in order to derive this knowledge, there needs to be research emphasis on Linking physicochemical identifiers to exposure and hazard identifiers, and attention should be given to a number of key cross-cutting issues have been identified which, among other things, include development of standards, dose metrics, high throughput techniques, modelling and integration into regulatory frameworks. Finally, the developed approach must be coherent and continuously updatable, supporting the unified framework required to ensure that we acquire sufficient, rigorously validated knowledge formulation of a robust reliable ITS and RA as quickly as possible. (C) 2014 Elsevier Ltd. All rights reserved.