Toward understanding aspects of the precautionary principle.

The idea of a precautionary principle (or precautionary principles) is beginning to come to the wider attention of the environmental community, governmental agencies, regulatory agencies, and the regulated community. Different precautionary principles have not been specified in detail, and, of course, this is difficult to do. Yet some specification must be done in order to understand it better and, if it is to be used for specific action-guidance, to implement it. Moreover, it is important to understand more about the principle, its background assumptions and its comparison with other principles to which we might subscribe. This paper explores aspects of the PP and its background assumptions and presuppositions, comparing them with those for risk assessment and other statements of the PP. It also briefly indicates how it resembles legal principles in addressing problems of uncertainty. Finally, it recapitulates two possible versions of the PP and suggests an application of it for an emerging threat to the environment and public health. This review suggests the PP has plausible applications and is not the radical principle some have suggested.