Probabilistic Safety Criteria for Accidental Situations

Overview

In going about their daily-life individuals continuously assess situations and make decisions on whether the risk associated to a particular action is justified. Such decisions are mostly made under conditions of uncertainty and involve value judgments that normally cannot be explicitly expressed in terms of quantitative criteria. This is often the case when the risk is of a voluntary nature,i.e., it is taken as a free choice (i.e., smoking, down hill skiing). On the other hand, when the individual cannot fully chose to avoid exposure to risk, it is termed as involuntary risk (e.g., natural disasters, large industrial accidents) and the decision making process needs to be more explicit using quantitative data. Moreover, people are generally willing to expose themselves to quite different levels of risk depending on whether it is of a voluntary or non-voluntary nature.