The role of chemistry in developing understanding of adverse outcome pathways and their application in risk assessment

The Adverse Outcome Pathway (AOP) conceptual framework has been presented as a logical sequence of events or processes within biological systems which can be used to understand adverse effects and refine the current risk assessment practice. This approach shifts the risk assessment focus from traditional apical endpoints to the development of a mechanistic understanding of a chemicals effect at a molecular and cellular level. In order to obtain this level of detail, chemistry in all its disciplines has a key role to play. Measurement techniques will be important in understanding chemical characterisation, free concentration and exposure at the site of interest. Such measurements will be vital in developing structure-based toxicological alerts and informing predictive models. This paper explores the areas where chemistry will be influential in the development of AOPs.