Life Sciences and Nano Sciences interact today mainly in two areas: in the evaluation of accidental health and environmental effects derived from engineered nanomaterials, and in development and biological/clinical evaluation of nanoparticles with intended biological effects for application in medicine and biotechnology. It is essential for producers, distributors, consumers and regulators that the safety of products containing nanomaterials can be certified with reliable, validated assays. Research efforts are under way to establish suitable test methods and to understand mechanisms potentially leading to a detrimental impact of nanomaterials on human health and on the environment. However, this important field still urgently lacks sufficient trained personnel. The ITN “Nanotechnology: Training Of Experts in Safety” (NanoTOES) will establish a network of research projects working towards the refinement and standardisation of existing methods, will develop novel assays, and will during this process provide interdisciplinary training to Early Stage Researchers (ESR) and Experienced Researchers (ER) working at the intersection of biosciences and nanosciences. A suite of methods developed and validated in the NanoTOES project shall have utility in characterising the biological effects of nanomaterials, including their impact on the environment, and will add significantly to our understanding of the biological actions of nanomaterials and their resultant effects on human health and the environment. Equally, the influence of biological entities (molecules, cells, tissues) on the properties of nanomaterials will be investigated. This aspect is crucial to understanding the properties of nanomaterials in organisms and in the environment, but nevertheless this issue has been so far not sufficiently explored. These timely and novel studies will address the pressing need for such trained personnel, and enable European science in this area to remain globally competitive.