The ultraviolet absorption spectrum and kinetics and mechanism of the self-reaction of CHF₂CF₂O₂ radicals have been studied in the gas phase at 298 K. Two techniques were used: pulse radiolysis UV absorption to measure the spectrum and kinetics and long-path-length Fourier transform infrared spectroscopy (FTIR) to identify and quantify the reaction products. Absorption cross sections were quantified over the wavelength range 220-270 nm. At 230 nm, σ_CHF2CF2O2 = (3-2 ± 0.5) × 10^-18 cm² molecule^-1. Errors are statistical (2 standard deviations) plus our estimate of potential systematic uncertainty (15%). This absorption cross section was used to derive the observed self-reaction rate constant for the reaction CHF₂CF₂O₂ + CHF₂CF₂O₂ → products (1), defined as -d[CHF₂CF₂O₂]/dt = 2k_1,obs[CHF₂CF₂O₂]². k_1,obs = (2.7 ± 0.6) × 10^-12 cm³ molecule^-1 s^-1 (errors are 2 standard deviations). Measured UV transients were not corrected for possible complications caused by formation of CHF₂O₂ and HO₂ radicals. Hence, k_1,obs may not be the true bimolecular rate constant for reaction 1. The only carbon-containing product observed by FTIR spectroscopy was COF₂. The carbon balance was, within our experimental uncertainty, 100%. As part of this work, a rate constant of (1.9 ± 0.2) × 10^-15 cm³ molecule^-1 s^-1 was measured for the reaction of Cl atoms with CHF₂CHF₂ using a relative rate technique. Results are discussed with respect to the atmospheric chemistry of haloalkanes.