Knowledge of chemical reactivity is essential for understanding at a molecular level the mechanistic steps that drive processes in life sciences. This COST Action aims to enhance the role of chemistry as a central discipline for understanding free radical biological events. This goal will be achieved through the implementation of biomimetic chemical models. Four working groups will focus on: enzymatic activities via free radical species; the formation and fate of free radicals involving nucleic acids; membrane lipids in stress and ageing; and synthetic methodologies inspired by natural free radical processes. The research groups participating in the Action will create an interdisciplinary framework, in which a younger generation of investigators can broaden their expertise by studying the diversity of free radical interactions in biological systems for metabolic, synthetic and catalytic activities through biomimetic models.