Smog chamber/FTIR techniques were used to study the Cl atom initiated oxidation of CF3OCF2H in 700 Torr of N-2/O-2 at 295 +/- 2 K. Atmospheric oxidation of CF3OCF2H proceeds via the formation of CF3OCF2 radicals. The atmospheric fate of CF3OCF2 radicals is addition Of O-2 to give CF3OCF2O2 radicals. In the atmosphere CF3OCF2O, radicals are converted via COF2 and CF3OH into CO2 and HF. Relative rate techniques were used to measure k(Cl + CF3OCF2H) = (2.3 +/- 0.3) x 10(-17) cm(3) molecule(-1) s(-1). The results are discussed with respect to the atmospheric degradation and environmental impact of CF3OCF2H.