The kinetics of reactions of CF3OCHFCF3 with hydroxyl radicals and chlorine atoms has been investigated using a discharged flow combined with both mass spectrometer and resonance fluorescence technique and using a relative rate technique, respectively, at 298 K. The rate constant for the reactions of CF3OCHFCF3 with OH and Cl was determined to be k(1) = (4.98 +/- 1.64) X 10(-15) cm(3) molecule(-1) s(-1) and k(2) = (3.1 +/- 2.5) X 10(-14) cm(3) molecule(-1) s(-1), respectively. On the basis of our kinetics measurements, the tropospheric lifetime of CF3OCHFCF3 is calculated to be about 8 years, primarily due to reaction with the hydroxyl radicals in the troposphere.