Page 101 - Materials Chemistry, Second Edition

L1644_C03.fm Page 76 Tuesday, October 21, 2003 3:11 PM

3.2 PHASES OF LIFE-CYCLE IMPACT ASSESSMENT
The general framework of the LCIA phase is composed of several mandatory
elements that convert life-cycle inventory results into indicator results. In addition,
there are optional elements for normalization, grouping and weighting of the indi-
cator results and data quality analysis techniques. The LCIA phase is only one part
of a total LCA study and should be coordinated with other phases of LCA. An
overview of the mandatory and optional elements in LCIA is given in Figure 3.1.
The mandatory LCIA elements are (ISO 14042, 2002):

• Selection of impact categories indicators and models
• Classification of environmental loads within the different categories of
environmental impact
• Characterization of environmental loads by means of a reference pollutant
typical of each environmental impact category

These categories, plus the level of detail and methodology, are chosen depending
on the goals and scope of the research.
Optional elements and information can be used depending on the goal and scope
of the LCA study (ISO 14042, 2002):

• Calculating the magnitude of category indicator results relative to refer-
ence values (normalization) means that all impact scores (contribution of
a product system to one impact category) are related to a reference situ-
ation.
• The indicators can be grouped (sorted and possibly ranked).
• Weighting (across impact categories) is a quantitative comparison of the
seriousness of the different resource consumption or impact potentials of

MANDATORY ELEMENTS
Selection of impact categories, category indicators, and models
(MODELS)

Assignment of LCI results (CLASSIFICATION)

Calculation of category indicator results (CHARACTERIZATION)

Environmental Profile (LCIA profile)

FIGURE 3.1 Mandatory elements of LCIA according to ISO 14042 (2002) (available at
www.afnor.fr).

© 2004 CRC Press LLC