Acceptance criteria for risks of disasters with widespread effects

The paper discusses special issues that arise in engineering decision‐making for engineering projects that involve a risk of potentially disastrous outcomes with widespread effects. For such projects, the costs, risks and benefits may spread beyond the jurisdiction of the relevant regulatory authorities, and the dispersion of the costs, risks and benefits may limit the accountability and liability of the decision‐makers. The paper briefly reviews the conventional methods for determination of risk acceptance criteria, and it includes a critical review of 'societal risk' criteria based on FN curves for risks involving potentially disastrous outcomes. The paper discusses the limitations of conventional engineering risk acceptance criteria and identifies additional factors that must be considered for rational risk‐informed decision‐making whenever there is a risk of a disastrous outcome.