Strengthening French participation to European calls is a major challenge. Applying to this MRSEI program will enable us to assess scientific visibility and benefit of the multidisciplinary network HuPlastiX on micro- and nano-plastics for a better human health risk assessment and management. Positioned at the interface between analytical chemistry, physiology, food toxicology, environmental sciences and toxicology, and circular economy, it will facilitate access and, hopefully, success to the H2020 funding program through the call SC1-BHC-03-2018 “Micro- and nano-plastics in our environment: Understanding exposures and impacts on human health”. Global plastic production has increased exponentially over the last decades. A significant proportion of the plastic produced is not disposed of properly and persists in the environment, especially the marine environment. Plastic products can be slowly degraded and fragmented into smaller pieces (defined as secondary micro-plastics when they are smaller than 5 mm and nano-plastics when they are < 1 µm). Primary micro-plastics may also be intentionally added to, for example, toothpaste and beauty products. Furthermore, plastic debris are associated with a “cocktail of contaminants” made up of chemical ingredients present originally in the plastic (additives such as bisphenols, phthalates) and chemical pollutants adsorbed to the plastic from the environment (e.g. metals, polychlorinated biphenyls (PCBs), flame retardants…). Due to their small sizes, micro-plastics are filtered into marine species’ gastrointestinal tract mechanically or they may look like food to some species, thus entering the food chain, with to date largely unknown effects. In fact, risk assessment studies and reviews carried out in recent years have concluded that there is evidence that humans are exposed to micro- and nano-plastics through their diet, drinking water or inhalation. However, understanding the fate and toxicity of these plastic particles in humans constitutes a major knowledge gap, rendering it difficult to carry out proper science-based risk assessment and management. The challenge of this call is to provide, notably through innovative approaches, policy relevant scientific data in support of improved human health hazard and risk assessment of micro- and/or nano-plastics. The following impacts are foreseen: (i) innovation in hazard characterization and health risk assessment methodologies for micro- and/or nano-plastics, (ii) better understanding of health impacts of exposure to micro- and/or nano-plastics, (iii) contribution to the health-relevant aims of the European strategy for plastics in a circular economy and of the bioeconomy strategy. Our proposal HuPlastiX aims to cover these expected impacts. As such, objectives cannot be reached on an individual country level; the targeted call thus needs intensive collaboration and synergies between scientists across disciplines. In line with this ambitious, albeit necessary, pre-requisite, we have started to build our consortium accordingly, while keeping in mind our own vision on how to tackle this cognitive and application-driven challenge on micro- and nano-plastics. By gathering specialists of the related fields, we aim to fulfill the gap between environmental and food toxicology, considering gut and its partners involved in maintaining host homeostasis. To support these biology-based findings, innovative methods will be implemented for detection and quantification of micro- and nano-sized plastics in the presence of additives and environmental pollutants. The ultimate goal will be to link the circular economy strategy of plastics with human health criteria, in order to facilitate the transition towards a modern, nutritionally sound and more sustainable society.