Nanotechnology is conceived as a Key Enabling Technology, becoming an increasingly research area providing functional materials to many industrial sectors, such as automotive, health, packaging, textiles, construction, etc. The main objective of DIAGONAL project is to increase the understanding on Multi-Component NanoMaterials (MCNM) and High Aspect Ratio Nanoparticles (HARNS) behavior along their life cycle from NM design and production to its application into Nano-Enabled products (NEP). DIAGONAL aims to bring new methodologies to guarantee long-term nanosafety and contribute to fill current gaps in: Risk Assessment, Risk Management and Risk Governance. DIAGONAL will bring Safe-by-Design knowledge and tools to a development stage which can be implemented in the MCNM and HARNs related industries, relying on experimental (in vitro) and modelling (in silico) research to understand and ultimately predict the interactions among the NM components, their transformation products, and between the NMs and the environment, promoting a better understanding of potential adverse effects on human health, and biota.