Since there is more than 20 million tons of biowaste produced in France every year, the exploratory project FLY4WASTE aims at assessing the benefits and risks of the insect-based bioconversion of these biowaste by the Black Soldier Fly, Hermetia illucens, in a context of circular bioeconomy. Indeed, the Black Soldier Fly Larvae (BSFL) can convert a wide variety of biowaste and be used as a new feed source. BSFL are rich in proteins and lipids and they can bioaccumulate different micronutrients, i.e. vitamins and minerals, as well as some phytochemicals such as carotenoids, depending on the substrate they are reared on. BSFL are increasingly used to feed animals because they are a more sustainable source of proteins than soya for example, and can be an alternative that provides proteins of good quality as well. Not all substrates on which BSFL can grow are approved for rearing larvae for animal feed for precautionary measures. Indeed, some chemical or microbiological contaminants might be present in these substrates and might be transmitted in the food chain. From a sustainability perspective, it would be preferable to use substrates that cannot be used to feed farm animals to feed BSFLs. Therefore we are going to study the organic waste from school canteens and from large and medium-sized supermarkets that are not yet authorized by the EU legislation and those already authorized: the agricultural by-products. The objective of the first task (C2VN, Marseille) is to measure the main macronutrients of interest in the larvae (proteins and lipids) as well as their content in fatsoluble micronutrients (carotenoids and vitamins A, D and E), to assess the ability of these substrates to improve the nutritional quality of the larvae. BSFL were reared on different biowaste at Avignon by the company BioMiMetiC. Lipids will be quantified following a modified Bligh& Dyer method and proteins using the Bradford method. Fat-soluble vitamins A, D and E and carotenoids will be quantified using a double extraction with hexane and HPLC quantification. Results will be presented during the congress. The second part of the project will focus on the identification and quantification of the potential chemical contaminants that might bioaccumulate in the larvae (INRAE, Clermont-Ferrand).