Page 97 - Materials Chemistry, Second Edition

LIFE CYCLE IMPACT ASSESSMENT 79

is interesting to note that the lifetime of LCIA methodologies (time elapsed
between two releases) has varied between 5 to 10 years. On one hand, this
reflects the high effervescence of research in LCIA over the last two decades,
which led to rapid methodological development. On the other hand, it also
reflects that LCIA is still in its infancy.
From a practical point of view, any given LCIA methodology older than 10
years is no longer likely to reflect the state of the art, thereby, showing seri-
ous methodological weaknesses. LCA practitioners should avoid using older
methods without at least checking the robustness of the results and conclu-
sions by performing a sensitivity analysis with a more recent methodology.
In the early 1990's, three methodologies were published that formed the
basis of three main schools of thought that influenced the subsequent develop-
ment of LCIA:

• Damage-Oriented (Area of Protection): The EPS (Environmental
Priority Strategies) methodology is based on a damage oriented
modeling approach and expresses results in monetary values.
First published in 1993 an updated version has been released in
2000 (Steen 1999). Category indicators are chosen to represent
actual environmental impacts on five safeguard subjects: human
health, ecosystem production capacity, biodiversity, abiotic
resources, and recreational and cultural values. Weighting factors
for the category indicators are determined according to people's
willingness to pay and expresses the price the society is ready to
pay in order to avoid these damages.
• Distance-to-Target: The Swiss Ecoscarcity (or Ecopoints) approach
is based on the distance-to-target principle. A first version was
published in 1991and has successively been updated to 1997
(Brand, Braunschweig et ah 1997). Eco-factors were originally
developed for Switzerland using the latest available statisti-
cal data and the supported goals of Swiss environmental policy
which set critical flows.
• Midpoint-Oriented: In 1992, the Centre of Environmental Science
(CML) at Leiden University produced a Guide and Background
document on the LCA methodology, known as the CML 1992
methodology (Heijungs, Guinee et al. 1992). This was the first mid-
point-oriented LCI methodology. Updated in 2002, CML claimed
to provide best practices for operationalizing the ISO14040 series
of Standards (Guinee, Gorree et al. 2002).

The knowledge gained in developing these three methodologies formed
the basis of LCIA methodology as it evolved. Following are brief descriptions
of the main LCIA methodologies that are currently used (Bare and Gloria
2006). Additional information on these approaches can be found in the ILCD
background document that analyzes existing environmental impact assess-
ment methodologies for use in LCA (EC-JRC 2010).