Exposure and environmental impact during the life cycle of manufactured nanomaterials The current and foreseen applications of manufactured nanomaterials embrace a wide range of technological domains. The release of nanoparticles from these nanomaterials in natural waters remains poorly investigated. However, such an environmental contamination will directly or indirectly (through trophic transfers) exposes the organisms to nanoparticles. Today, all nano-ecotoxicological studies performed towards organisms show that it is impossible to study the impacts of nanomaterials all along their life cycle with a case-by-case approach. Consequently, it is necessary to anticipate the risk related to these new materials and to develop a new generation of safer by design nanomaterials from the earliest production stages of nanoparticles, to their formulation, their incorporation in the final product, the use of this product, and also to their end of life (recycling, disposal).