Environmental life cycle assessment of products : guide and backgrounds (Part 1)

Abstract

This preface gives an overview of some developments in the state-of-the-art of LCA since the conception of the original report.The Society of Environmental Chemistry and Toxicology (SET AC) is the current leading international organization in the coordination of the methodological development of life cycle assessment.In April 1993, an expert workshop was held in Sesimbra, Portugal, with the aim of establishing an internationally agreed Code of Practice.This included the definition of a technical framework for LCA consisting of components (as in Figure 0.1) and a uniform terminology.The framework and terminology developed in this report differ slightly from that provisionally developed by SETAC.To avoid confusion we have provided an overview of the main differences here.This is followed by a comparison of the framework and terminology used in this report and that in the Code of Practice.The framework in this report consists of five components.The draft Code of Practice consists of four components.The main difference concerns the components classification and evaluation in the present report.These are part of the impact assessment in the SETAC framework.Classification as used in this report is subdivided into classification and characterization in the Code of Practice, where the former denotes the labeling of inputs and outputs according to the effect categories they contribute to, and the latter amounts to the weighting and aggregation into scores for these effect categories.The similarities and the differences between the two approaches are summarized in the table below.Code of Practice Sesimbra -April 1993 Guide + Backgrounds LCA -October 1992 goal definition and scoping goal definition inventory analysis inventory analysis , classification \ } classification impact assessment -j characterization J valuation evaluation improvement assessment improvement analysisIn this study the term impact has been avoided.Interventions indicate human interference in the environment, e.g.resource extraction and emissions (environmental releases).Effects indicate the resulting environmental problems, e.g.resource depletion and acidification.Further differences in terminology are minor.SUMMARY with a summary process tree and separate trees for individual parts of the summary process tree. The extraction of raw materials from the environment is considered as the start of the life cycle. Although waste processing is considered as the end of the life cycle it is treated as an economic process which affects the environment through the consumption of raw materials, emissions and in other ways.Similarly, waste treatment steps carried out before a substance is introduced into the environment are included as part of the product system.No POCP has yet been defined for nitrogen oxides hence the quantity of NO, emitted is included separately as a "flag", see 3.3.1.