The Link Between Life Cycle Inventory Analysis and Life Cycle Impact Assessment

Book chapter, 2021

In this chapter, the link between life cycle inventory analysis (LCI) and life cycle impact assessment (LCIA) is discussed. For the feasibility of conducting a life cycle assessment (LCA) and for making its results more robust, it is necessary that data collected in the LCI stage are suitable for the LCIA methods, and in particular for comparative studies, it is relevant to provide matching levels of detail for all compared options. Four illustrative examples are provided: (i) the differences in receiving compartment resolution for toxic emissions, (ii) differences in stressor resolution for particulate matter formation, (iii) lacking characterization factors for metal use, and (iv) lacking characterization factors for sum parameters and not fully specified emissions (such as BOD, TOC and “alkanes, unspecified”). Two important lessons to consider for maintaining a strong link between LCI and LCIA are highlighted based on these examples. First, it is suggested that it is important to have the same resolution between LCI data and LCIA methods. Scenario analysis, where different resolutions are assumed and tested, can be a strategy in cases where differences in resolutions are unavoidable. Second, ways to handle the absence of characterization factors are discussed, including the development of additional characterization factors that match the available LCI data and derivation of characterization factors from process information.