What is hazardous? What is safe?

The definition of an acceptable risk involves many facets most of which are outside the control of the decision maker, but they must be recognized if a proper definition is to be made. Six of the principal factors are stated and discussed. (1) nothing is absolutely safe; (2) each individual or group of individuals has his own standards by which he judges risk; (3) perceptions of risk vary with the conditions at any one time in history; (4) there must be a compensatory benefit for taking any risk; (5) societal perception of a risk may be different from the actual risk; and (6) safety is only one of the many factors that must be considered in the design of a product or service.