Page 72 - Materials Chemistry, Second Edition

56 2 Goal and Scope Definition

An evaluation of the accuracy of data records is difficult, as process
data are usually not available with variants, error margins or standard
deviations. The evaluation is thereby essentially based on qualitative expert
knowledge. Therefore, for a descriptive evaluation of the data material,
available information such as, the average of a used technology, the year
of reference, and so on, has to be consulted. Thus, above all, information
is obtained on how representative the data are. Exceptions are packaging
specifications of the beverage cartons. Here, a mapping of qualified band
widths is possible.

2.3.2.8 Type of Life Cycle Impact Assessment
At this stage impact categories to be considered are already defined. From this
results the data set to be procured in the inventory analysis (see Table 2.1).

Table 2.1 Correlation of inventory parameters procured in the project and impact
categories (for explanation of the impact categories, see Chapter 4).

Impact category Substantial LCI parameter a Unit of category indicator

Resource demand Crude oil, raw gas, brown coal, kg of crude oil
hard coal equivalents
Land use Spatial categories II–V m 2
Greenhouse effect b CO fossil, CH ,CH kg CO -equivalent
2 4 4 2
regenerative, N O, C F ,CF ,
2 6
4
2
CCl
4
Eutrophication NO ,NH 3 kg PO 4 3− -equivalent
x
(terrestrial)
Acidification NO ,SO ,H S, HCl, HF, NH , kg SO -equivalent
x 2 2 3 2
TRS
Photo smog ∼ ozone NMVOC, VOC, benzene, CH , kg of ethene equivalents
4
formation (near acetylene, ethanol,
surface) formaldehyde, hexane, toluene,
xylene, aldehydes unspecified.
+ 3−
Eutrophication P-total, CSB, N-total, NH 4 , kg PO 4 -equivalent
(aquatic) NO 3 − ,NO 2 − , N unspecified
a The complete lists of inventory parameters considered in the example can be found in Sections
3.7 and 4.6 for illustration of the phases Inventory Analysis and Impact Assessment.
b The impact category ‘climate change’ is designated as ‘greenhouse effect’ in the example.
TRS, total reduced sulphur; NMVOC, non-methane volatile organic substances; VOC, volatile
organic compounds; CSB, chemischer Sauerstoff-Bedarf.

63) Since in the examined systems ozone-destroying substances are not released in relevant
quantities, the impact category ‘stratospheric ozone depletion’ is omitted.