A PROPOSAL FOR THE DEFINITION OF RESOURCE EQUIVALENCY FACTORS FOR USEIN PRODUCT LIFE-CYCLE ASSESSMENT

Environmental life-cycle assessment (LCA) of products has been the foc us of growing attention in the last few years. The methodological fram ework has been developed rapidly, and a provisional ''Code of Practice '' has been drawn up by an international group of experts. One of the elements of LCA is impact assessment, which includes a characterizatio n step in which the contributions of resource extraction and polluting emissions to impact categories such as resource depletion, global war ming, and acidification are quantified and aggregated as far as possib le. This can be achieved by multiplying extractions and emissions by a so-called equivalency factor and aggregating the results in one or mo re effect score(s) per impact category. In this report a proposal is d eveloped for equivalency factors indicating the relative depletion of a resource per unit extracted. It is proposed to measure depletion by physical data on reserves and production and regeneration rates, and t o distinguish between abiotic and biotic resources. Equations are deve loped to calculate equivalency factors for these two categories of res ources, resulting in so-called abiotic depletion potentials (ADP) and biotic depletion potentials (BDP). The application of these ADPs and B DPs in LCA is illustrated.