Evaluation and decision-making processes in life cycle assessment

ConclusionNeither quantitative nor toxicological criteria can be used for decision making without an evaluation process in which objectives are defined. Science must monitor this process, but cannot be responsible for the political function of setting priorities. The possibilities of science in this context are often over-estimated. In addition, defined priorities must be reviewed at regular intervals as the statements made on the basis of this methodology will not necessarily remain valid permanently.With action-oriented priority lists, risk perception also plays an important role. This depends on the information available and the degree to which damage is perceived, and is determined by the social consensus as to what constitutes damage.It is essential that the priority-defining methods are transparent. This calls for careful documentation of the basic data. Only if the methodological limitations with regard to priority definition are indicated and identified is it possible to hold action-oriented discussions and to obtain acceptance for a chosen method, however, impermanent and inevitably imperfect it might be.