Chemistry Reference
In-Depth Information
is to happen, then further development of LCA
has to be directed towards its meeting the needs
and expectations of these stakeholders. It is only
then that we can expect this approach to become
integrated fully into corporate and public policy
decision-making.
the GWP factors for longer periods (100 and 500
years) are used to predict the cumulative effects of
these gases on the global climate.
Ozone depletion potential
The ozone depletion potential (ODP) category indi-
cates the potential of emissions of chlorofluorohy-
drocarbons (CFCs) and chlorinated hydrocarbons for
depleting the ozone layer and is expressed as:
5 Appendix
5.1 Definition of environmental impacts
J
Â
This section gives an overview of the calculation
procedure to estimate the contributions of burdens
identified in the Inventory Analysis phase to the dif-
ferent impact categories. The procedure is based on
the problem-oriented approach [21]. All impact cat-
egories are normalised to the functional unit. The
numerical values of the classification factors of some
of the burdens are given in Table A5.1.
E
=
ec
B
()
kg
(A1.3)
3
3
,
j
j
j
=
1
where
B
j
is the emission of ozone-depleting gas
j
. The
ODP factors
ec
3,
j
are expressed relative to the ozone
depletion potential of CFC-11.
Acidification potential
Acidification potential is based on the contributions
of SO
2
, NO
x
, HCl, NH
3
and HF to the potential acid
deposition, i.e. on their potential to form H
+
ions.
Acidification potential is calculated according to the
formula:
Abiotic resource depletion
Abiotic resource depletion includes depletion of non-
renewable resources, i.e. fossil fuels, metals and min-
erals. The total impact is calculated as:
J
Â
E
=
ec
B
()
kg
(A1.4)
J
B
ec
4
4
,
j
j
Â
j
E
=
(A1.1)
j
=
1
1
1
,
j
j
=
1
where
ec
4,
j
represents the acidification potential of
gas
j
expressed relative to the acidification potential
of SO
2
, and
B
j
is its emission in kilograms per func-
tional unit.
where
B
j
is the quantity of a resource used per func-
tional unit and
ec
1,
j
represents the total estimated
world reserves of that resource.
Global warming potential
Eutrophication potential
Global warming potential (GWP) is calculated as a
sum of emissions of the greenhouse gases (CO
2
, N
2
O,
CH
4
and VOCs) multiplied by their respective GWP
factors,
ec
2,
j
:
Eutrophication potential is defined as the potential
to cause over-fertilisation of water and soil, which
can result in increased growth of biomass. It is
calculated as:
J
J
Â
E
=
ec
B
()
kg
(A1.2)
Â
E
=
ec
B
()
kg
(A1.5)
2
2
,
j
j
5
5
,
j
j
j
=
1
j
=
1
where
B
j
represents the emission of greenhouse gas
j
. The GWP factors,
ec
2,
j
, for different greenhouse
gases are expressed relative to the global warming
potential of CO
2
, which is therefore defined to be
unity. The values of GWP depend on the time
horizon over which the global warming effect is
assessed. The GWP factors for shorter times (20 and
50 years) provide an indication of the short-term
effects of greenhouse gases on the climate, whereas
where
B
j
is an emission of species such as NO
x
, NH
4
+
,
N, PO
4
3-
, P and COD, and
ec
5,
j
are their respective
eutrophication potentials. Eutrophication potential
is expressed relative to PO
4
3-
.
Photochemical oxidants creation potential
Photochemical oxidants creation potential (POCP),
or photochemical smog, is usually expressed relative
