Risk evaluation: criteria arising from legal traditions and experience with quantitative risk assessment in the United States.

Making use of quantitative estimates of risk involves sometimes painful choices about risk control options and ethical and social policies for additional control and/or acceptance of remaining risks. Out of the history of these choices in the U.S., we have drawn four broad categories of risk control criteria: The first of these is entirely qualitative; the last three can be informed by different kinds of quantitative analyses. The analyses differ in the implications of variability and uncertainty, among other factors. These suggested criteria should not be seen as a kind of formula to be programmed into a computer in place of human decision making. Rather, we hope they will contribute to an evolving language that can accurately represent our advancing technical understanding of the facts and frankly and compassionately convey our maturing understanding of the relevant value questions.