The kinetics and products of the Cl atom initiated oxidation of CF3CFHOCF3 in 50-700 Torr of air, or N-2, diluent at 295 2 K were studied using smog chamber/FTIR techniques. Relative rate methods were used to measure k(Cl + CF3CFHOCF3) = (6.0 +/- 0.8) X 10(-17) cm(3) molecule(-1) s(-1). The reaction of Cl atoms with CF3CFHOCF3 proceeds substantially (approximately a factor of 500) times slower than reported recently by Li et al. [Chem. Phys. Lett. 320 (2000) 70]. The atmospheric degradation of CF3CFHOCF3 gives the alkoxy radical CF3CFO((.))OCF3. The atmospheric fate of CF3CFO((.))OCF3 radicals is decomposition via C-C bond scission to give FC(O)OCF3 and CF3 radicals. The atmospheric degradation mechanism of CF3CFHOCF3 is discussed. (C) 2002 Elsevier Science B.V. All rights reserved.