The use of quantitative risk criteria in hazard analysis

Abstract

The approach to the reduction of risk to employees, the public and the environment must be a practical one. Since life is full of risks, we cannot completely eliminate risks associated with industry, but we should be able to establish levels of risk which society considers acceptable and deploy our resources in the most effective manner in trying to achieve these levels. We therefore need quantitative criteria to define these socially acceptable levels. If the criteria are thoughtfully and responsibly chosen, we should find that they can usually be met, but inevitably there will be a few isolated cases where the level will be extremely difficult to achieve. We therefore also need a policy which ensures that in these cases we neither ignore the problem, nor do we use our resources inefficiently by trying to eliminate that particular problem at all costs when there are many other problems which could be more fruitfully tackled with the same resources. In other words, we need to be able to define consistently in quantified terms the phrase used in statutory regulations “so far as is reasonably practicable”. This article defines certain risk criteria which I suggest might be accepted by society and describes an approach for dealing with risks which exceed these criteria. The approach suggested is a cost benefit analysis; one of the difficulties in this area and one that others have reported [1–3] is assigning a value to the amount of money which should be spent to save a life. To take some of the emotion out of the subject, I have called this amount the “Socially Acceptable Premium (SAP)”.