Manufacturing and functionalising materials at the nanoscale leads to a whole array of nanomaterials (NMs) varying in e.g. size, morphology and surface characteristics. Apart from expected benefits, distinctive properties of NMs may also affect (environmental) health risks. Safety assessment requires sufficient information for each NM, but testing every unique NM for their potential adverse effects is virtually impossible. More efficient ways to obtain safety information are needed, which could be achieved by applying grouping and read-across approaches to NMs. On a conceptual level, regulatory accepted approaches for grouping and read-across for NMs already exist, but actual application remains difficult as the required knowledge is not systematically brought together, lacks data curation or is still missing. GRACIOUS will address this urgent need by developing a framework for grouping and read-across based on physicochemical, release, exposure, environmental fate, toxicokinetic and toxicological information. This framework will be delivered as a practical e-tool, fit-for-purpose for various key (regulatory and industrial) stakeholders, who will be engaged from the start of the project. To develop the framework, GRACIOUS will build upon currently available approaches by collating, curating and assimilating existing and new knowledge on intrinsic and extrinsic physicochemical properties in relation to their (environmental) health risk. The resulting framework will support safe innovation by enabling considerations of safety a.o. via grouping and read-across in industrial decision making at various stages of product development. For regulators and policy makers, GRACIOUS will facilitate actual application of grouping and read-across of NMs to enable risk analysis of NMs without extensive testing.