The Cambridge 2-D Eulerian model has been used to study the potential
atmospheric distributions and lifetimes of a number of CFC replacement
compounds and their degradation products. The study has focused on HF
C 134a and HCFCs 123, 141b and 142b and the major products formed by t
heir atmospheric degradation. The loss of these compounds and their pr
oducts by hydroxyl radical attack, photolysis and in-cloud hydrolysis
have been investigated. The study has shown that HCFCs 141b and 142b h
ave sufficiently long lifetimes to enter the stratosphere in significa
nt quantities, where degradation leads to an increase in the total str
atospheric chlorine concentration. The study has also highlighted area
s where further experimental work would be valuable, in particular cha
racterisation of the product channels for the degradation reactions an
d determination of the removal rates of the products in the aqueous ph
ase.