The ultraviolet absorption spectrum of CF₃CH₂O₂ radicals, the kinetics of their self-reaction, and their reactions with NO and NO₂ have been studied in the gas phase at 296 K using a pulse radiolysis technique. A long path-length Fourier transform infrared technique was used to study the fate of CF₃CH₂O radicals. Absorption cross sections were quantified over the wavelength range 220-300 nm. At 250 nm, σ(CF₃CH₂O₂) = (2.73 ± 0.31) × 10^-18 molecule^-1. By monitoring the rate of NO₂ formation, k₄ = (1.2 ± 0.3) 10^-11 cm³ molecule^-1 s^-1 was found for the reaction of CF₃CH₂O₂ radical with NO. The reaction of CF₃CH₂O₂ radicals with NO gives CF₃CH₂O radicals. In the atmosphere, >99.3% of the CF₃CH₂O radicals react with O₂ to give CF₃CHO. By monitoring the rate of NO₂ decay, k₅ = (5.8 ± 1.1) × 10^-12 cm³ molecule^-1 s^-1 was found for the reaction of CF₃CH₂O₂ radical with NO₂. The results are discussed with respect to the atmospheric chemistry of CF₃CH₃ (HFC-143a). As a part of the present work, relative rate techniques were used to measure the following rate constants: (2.6 ± 0.7) × 10^-12 and (2.0 ± 0.5) × 10^-12 for the reaction of F atoms with CF₃CH₃, (5.5 ± 0.3) × 10^-11 for the reaction of F atoms with CF₃CH₂OH, and (3.6 ± 0.2) × 10^-17 for the reaction with Cl atoms with CF₃CH₃ (units of cm³ molecule^-1 s^-1).