Risk assessment and laser safety

The basic tenets of risk assessment have always been applied in laser safety during the development of safety standards. For example, statistical methods were used in the probit analysis of the threshold of ocular injury; concepts of risk analysis were employed in the development of hazard classes, where the increased risk of exposure and potential for injury from increasing laser output power led to assignment of an increasing hazard class. In recent years, however, there has been a number of attempts to apply statistical probability analysis in the risk assessment of actual use conditions. However, once the hazard classification has been assigned, how should one further apply the techniques of risk assessment in the determination of hazard control measures, or does this lead to a potential controversy of what is the risk? Risk analysis is the evaluation of potentially hazardous exposure conditions coupled with a realistic assessment of actual human exposure. The maximum permissible exposure values for laser radiation coupled with the laser hazards classification scheme, already permit realistic health hazard evaluations. However, in determining effective hazard control measures, one must perform a risk analysis. A risk analysis must consider aspects of human behaviour and how behaviour affects exposure. This is frequently the area of greatest controversy in the derivation of safety standards; however, it is this aspect where standards are most needed.