Risk consequence scales as routinely applied by specialist professions not specialist in risk assessment, refer to single fatality events as “Catastrophic”, many potential events can reasonably be expected to result in multiple fatalities. This type of event is particularly relevant where large numbers of people are exposed or where high energies are involved. High hazard process plants, air or train travel, ferry travel and even bus travel are examples of fairly routine situation where the consideration of risk must consider truly catastrophic outcomes.
Use of routine risk scales that rate single fatality and multiple fatality consequence as the same level of concern result is results where nominally the same effort must be expanded preventing a single fatality risk vs a multi-fatality risk. This is patently not logical where resources are not limitless.
A further question is whether a potential event where 10 people are exposed is quantitatively equal to 1o times that where one person is exposed. It is evident that society reacts multiple fatality events with greater concern than with a level greater than the number of persons involved in the one event. Examples of this are Cave Creek (16 young people) and Pike River (29 miners). In each case New Zealand society reacted with grave concern. However, is a equal level of concern exhibited for similar numbers of workers being killed over an extended period?
The attached paper addresses this aspect of scaling consequences.