Food contamination may be a global food safety issue. There are many potentially toxic substances within the environment which can contaminate foods consumed by people. A circular food system is one within which waste material is processed to recover plant nutrients and returned to the soil to enable the assembly of more food, instead of being diverted to landfill or incineration. The approach could also be accustomed reduce energy and water use in food production and contribute to the sustainability of the system. this text brings together information on several chemical contaminants at different stages of the food supply chain, their possible sources. the most aim is to spot factors that might impede the transition towards a secure, reliable and efficient circular food system.