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Characterisation Method Information
Characterisation Method Name:
Contributions to ODP
Version:
1997
Date Completed:
1997
Principal Method Name:
EDIP: ozone depletion potential
Method Description:
Stratospheric ozone is broken down as a consequence of man-made emissions of halocarbons, i.e. CFCs, HCFCs, halons and other longlived gases containing chlorine and bromine. The ozone content of the
stratosphere is therefore decreasing, and since 1985 a dramatic temporary thinning of the ozone layer, often referred to as the "ozone hole", has been observed each year, over the South Pole. In the last few years the depletion of ozone has also accelerated over the northern hemisphere. As
a consequence of this the intensity of hazardous ultraviolet radiation at the earth's surface has increased over parts of the southern and northern hemispheres. This can have dangerous consequences in the form of increased frequency of skin cancer in humans and damage to the plants which form the basis of all ecosystems.
The stratospheric depletion of ozone is an impact which affects the environment on a global scale.


1 Determine which substances contribute to ozone depletion

For a substance to be considered as contributing to stratospheric ozone depletion, it must
be a gas at normal atmospheric temperatures,
contain chlorine or bromine,
be stable with a lifetime in the atmosphere of several years to centuries, to allow for its transportation up into the stratosphere.

The man-made substances contributing to the stratospheric breakdown of ozone are simple gaseous organic compounds with a substantial content of chlorine or bromine. The most important groups of ozone-depleting halocarbons are the CFCs, the HCFCs, the halons and methyl bromide. In contrast to these, the HFCs are a group of halocarbons which contain neither chlorine nor bromine but only fluorine, and which are therefore not regarded as contributors to stratospheric depletion of ozone.
CFCs and HCFCs are used mainly as foaming agents in foam plastic, as refrigerants and as solvents. Halons are used as fire-extinguishing agents in fire-fighting equipment. Methyl bromide is used in the disinfection of buildings and of soil in market gardens.

The production of halocarbons is regulated under the Montreal Protocol by the UN. Under this protocol, production of CFCs and halons
ceased in the industrialized world on 1 January 1996. Consumption of methyl bromide was frozen in 1995, and consumption of HCFCs is to be decreased gradually. The deadlines for phasing out have been brought forward in a number of countries. CFCs and halons can, however, continue to be produced in Third World countries until 2010 (UNEP, 1993), and they will therefore also occur in future in inventories of product systems.

As for the greenhouse gases, the list of compounds considered as contributing to the stratospheric depletion of ozone is short and can be regarded as exhaustive. In practice it will therefore not be necessary to check a substance under the above criteria to decide whether it contributes to ozone depletion. It will be sufficient to consult the list of equivalency factors in the following section.

2 Calculate the ozone depletion potential

Together with the UN's environment programme UNEP and a number of other organizations, the World Meteorological Organization (WMO)
organizes the "Global Ozone Research and Monitoring Project", a research network of experts in atmospheric chemistry. The network reviews international developments in scientific knowledge of stratospheric ozone depletion and every few years issues status reports summarizing the latest findings. The status reports present the Ozone Depletion Potentials (ODPs), which for individual gases express the ozone depletion potential as an equivalent emission of a reference substance CFCII (CFCI3). These ODP values are used as equivalency factors in the calculation of the ozone depletion potential. The equivalency factor is thus defined as:

EF(od)=ODP=Contribution to stratospheric ozone depletion from gas(i)/contribution to stratospheric ozone depletion from CFC11

The focus in this definition is on the gas's total contribution to stratospheric ozone depletion throughout its life in the atmosphere. If the plans for phasing out halocarbons in the Montreal Protocol are followed, the breakdown of ozone in the stratopshere is predicted to peak within the next 10 years, and the problem will then gradually decline. On this basis the contribution to ozone depletion realized within the next few years
can be viewed as more serious than contributions which will only be realized in the distant future. It can therefore be more relevant to view the gases' contributions in a significantly shorter time perspective. For the most short-lived of the gases, especially the HCFCs, this will result in some markedly larger equivalency factors.

In accordance with general LCA practice, the EDIP method does, however, recommend use, for equivalency factors, of ODP values representing the gases' full contributions.

Literature Reference:
Henrik Wenzel, Michael Hauschild and Leo Alting (1997 ): Environmental assessment of products Vol. 1 Methodology, tools and case studies in product development London Chapman & Hall
Methodological Range:
Geographical range is global. Time range is 100 years.
Notes:

Existing Characterisation Factors of Contributions to ODP
Characterisation Parameter Category Indicator Impact Indication Principle Aspect Substance Quantity Unit Notes
CFactor ODP EDIP/1997
Type = Emission
Direction = Output
Media = Air
Geography = *
1,1,1-Trichloroethane 0.15 g/g
CFactor ODP EDIP/1997
Type = Emission
Direction = Output
Media = Air
Geography = *
CFC-11 1 g/g
CFactor ODP EDIP/1997
Type = Emission
Direction = Output
Media = Air
Geography = *
CFC-113 0.78 g/g
CFactor ODP EDIP/1997
Type = Emission
Direction = Output
Media = Air
Geography = *
CFC-114 0.78 g/g
CFactor ODP EDIP/1997
Type = Emission
Direction = Output
Media = Air
Geography = *
CFC-115 0.78 g/g
CFactor ODP EDIP/1997
Type = Emission
Direction = Output
Media = Air
Geography = *
CFC-12 0.78 g/g
CFactor ODP EDIP/1997
Type = Emission
Direction = Output
Media = Air
Geography = *
Halon 1211 4.9 g/g
CFactor ODP EDIP/1997
Type = Emission
Direction = Output
Media = Air
Geography = *
Halon 1301 11.5 g/g
CFactor ODP EDIP/1997
Type = Emission
Direction = Output
Media = Air
Geography = *
HCFC-141b 0.13 g/g
CFactor ODP EDIP/1997
Type = Emission
Direction = Output
Media = Air
Geography = *
HCFC-142b 0.08 g/g
CFactor ODP EDIP/1997
Type = Emission
Direction = Output
Media = Air
Geography = *
HCFC-22 0.07 g/g
CFactor ODP EDIP/1997
Type = Emission
Direction = Output
Media = Air
Geography = *
Methyl bromide 0.69 g/g
CFactor ODP EDIP/1997
Type = Emission
Direction = Output
Media = Air
Geography = *
Tetrachloromethane 1.14 g/g