How can science and policy making support each other for the best possible results? Sometimes it is not possible withing the policy making procedurs to wait for definitive proof, this can mean exposing people to an avoidable hazard, with potentiallydevastating effects. When science is being used to help make policy decisions, precision is not the only goal. This booklet focues on the principle of precaution within the legislative processes – it’s all about making intelligent decisions under uncertainty.