168 Introduction to Renewable Biomaterials
Midpoint indicators Endpoint indicators
Human health
Natural environment
LCI results
Natural resources
Climate change
Ozone depletion
Human toxicity
Respiratory inorganics
Ionising radiation
Noise
Accidents
Photochemical ozone
Formation
Acidification
Eutrophication
Ecotoxicity
Land use
Resource depletion
Dessication salination
Figure 5.8The relationship between end point and midpoint impacts as proposed by the ILCD
Handbook (Wolfet al., 2012).
impacts to the environment that the study is addressing. For instance, if quantifying
fossil fuel usage of a product is a stated goal, the impact assessment method must
calculate this to enable the interpretation of results.
There are primarily two main types of impact assessment methods: midpoint and end
point impact assessment methods (Goedkoop and Spriensma, 2001; Bareet al., 2006).
The midpoint indicator methods are closely tied to science and are based on more
exact models. As there are fewer assumptions associated with midpoint indicators,
they generally have less uncertainty than end point indicators. End point indicators
are useful in that they are easier to understand and are more appealing to a general
audience (Figure 5.8).
5.3.2.11 Classification
Classification is the second of the ISO mandatory LCIA steps where emissions are
sorted into groups that have an impact on a midpoint indicator. Figure 5.9 lists LCI
data of different elemental flows and then shows arrows grouping the emissions to
From LCI:
Carbon dioxide
Chlorofluorocarbons
Methane
NOx
VOC
Pollutants Mind-pointindicator
Acid rain
Ground level
ozone
GHG effect
Mid-point indicators
Figure 5.9Classification of LCI data into midpoint indicators.
