A logarithmic approach for individual risk: the safety-index

摘要

Risk analyses can be undertaken to examine the required safety measures that are needed to realise complex projects near hazardous installation. When doing this risk analysis, the results have to be checked for risk acceptance criteria. In this paper, the three main criteria for risk acceptance criteria, which can be divided into individual risk, risk on a social basis and the economic criterion, are analysed and their interrelation is described. One of the relations between these criteria is the expected number of casualties. To quantify this expected number of casualties in term of economics, the expected numbers of casualties are taken into account by using monetary value per casualty. This paper discusses the variation of the monetary value per casualty. Furthermore, the acceptable level for societal risk is analysed for different countries. Finally, a new approach for the individual risk criterion on logarithmic scale, namely the safety-index is discussed in this paper. This paper describes a full derivation of the safety-index. Besides, on the basis of the safety-index, a dimensionless criterion for individual risk is proposed. The safety-index provides an effective tool for the assessment of individual risk dimensionless regarding the acceptance of risk.