Registration Dossier

Administrative data

Endpoint:
mode of degradation in actual use
Adequacy of study:
supporting study

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Radiative forcing of climate change. The 1994 report of the Scientific Assessment Group. Summary for Policy Makers.
Author:
Intergovernmental Panel on Climate Change
Year:
1995
Bibliographic source:
IPCC, Hadley Centre, Meteorological Office, Bracknell, UK p28.
Reference Type:
publication
Title:
Climate Change 2001: The scientific basis. Contribution of Working Group I to the 3rd assessment report of the IPCC
Author:
Intergovernmental Panel on Climate Change
Year:
2001
Bibliographic source:
Cambridge University Press, Cambridge, UK.
Reference Type:
publication
Title:
Global ozone research and monitoring project, scientific assessment of stratospheric ozone. Report 44.
Author:
WMO
Year:
1998
Bibliographic source:
World Meteorological Associated, Geneva, Switzerland
Reference Type:
publication
Title:
Source gases. Global ozone research and monitoring project, scientific assessment of stratospheric ozone. Report 47.
Author:
WMO
Year:
2002
Bibliographic source:
World Meteorological Association, Geneva, Switzerland, pp1.54, 1.57
Reference Type:
publication
Title:
The atmospheric degradation and impact of 1,1,1,2-tetrafluoroethane (hydrofluorocarbon 134a)
Author:
Franklin J
Year:
1993
Bibliographic source:
Chemosphere 27: 1565-1601

Materials and methods

Test material

Reference
Name:
Unnamed
Type:
Constituent

Results and discussion

Applicant's summary and conclusion

Executive summary:

The atmospheric degradation of HFC-134a occurs mainly in the troposphere, initiated by reaction with naturally occurring hydroxyl radicals (photo-oxidation), and in the stratosphere through photolysis and reaction with O(1D) and OH. Both tropospheric and stratospheric degradation processes were taken into account to calculate an overall atmospheric lifetime of 14 years (IPCC, 1994), corresponding to a half-life of 9.7 years. More recent estimations remained very close to this value, i.e. 13.6 years (WMO, 1998), 13.8 years (IPCC, 2001) or 14.0 years (WMO, 2002). The atmospheric lifetime of HFC-134a is much longer than either the intra- or inter-hemispheric mixing times. As a consequence, HFC-134a will become more or less uniformly distributed in the atmosphere on a global scale (Franklin, 1993). This conclusion is supported by atmospheric measurements.