Risk assessment is a process for identifying adverse consequences and their associated probability. As applied to impacts on human health from contaminant residuals in food, risk assessment involves four steps — (i) determination of exposure media (food) contaminant concentrations; (ii) exposure assessment; (iii) toxicity assessment; and (iv) risk characterization. The goal of this paper is to provide an overview of the risk assessment process and identify terminology and methods. In the area of public health protection, risk assessment has proven most useful when applied to endpoints with high negative value (or negative utility) — such as disasters and irreversible diseases such as cancer and birth defects. Less success has been attained when it is applied to reversible and/or threshold-type diseases such as muscle dysfunction and neurological effects. We will consider why this is and what this implies for the application of risk assessment to a broader range of human diseases and low likelihood impacts. An important issue in health risk assessment is how precisely we can characterize the distribution among individuals and/or species of potential effects and whether this level of precision favours one or another action.