Science and the Precautionary Principle

The Precautionary Principle has become enshrined in international law, and is the basis for European environmental legislation. However, decisions have been controversial, and the principle itself lacks clear definition. A recent commentary by the European Commission offers guidelines for politically transparent application of the principle, while emphasizing the need for careful review of relevant scientific data. Recent precautionary policies for limiting public exposure to radio-frequency energy shows that the principle can be applied in a way that does not conflict with traditional exposure guidelines. Major uncertainties still remain in the standard of proof needed to invoke the principle.