Extending the characterization of risk beyond the dimension of how much, to the dimensions of who, what, when, where and why, presents opportunities to enhance the understanding of risk by the public and by the regulator, and to improve risk management. These added dimensions should be used only as a supplement to the standard probability‐based description of risk. They should be restricted to those situations in which they enhance the likelihood of informed decisionmaking, are easy to develop technically, and are not likely to add to the existing paralysis in regulatory decisionmaking. The dimension of time during which an adverse event is expected to occur potentially is of great value. It can be used to restore the public health base to environmental decisionmakin