Currently, more than ten federal statutes contain statements about risk and benefit assessment; the process of setting environmental standards increasingly rests on the analysis of risk. The courts have made numerous references to risk-benefit analysis in reviewing the actions of regulatory agencies. Yet the issue of what role risk-benefit assessment should have in energy or environmental policy is neither clear nor settled. One reason is that many of the questions that arise in attempting to evaluate risk are what Weinberg (1) has called "questions which can be asked of science and yet which cannot be answered by science . . . they transcend science." Another is that 58decisions on how to measure or reduce risk are not purely scientific ones; they are policy choices as well, enveloped in the controversy that usually accompanies policy disagreements.