Using the pulse radiolysis UV absorption technique and subsequent simulations of experimental absorption transients at 254 and 276 nm, upper limits of the rate constants for the reactions of CF₃O₂ and CF₃O radicals with ozone were determined at 295 K, CF₃0₂+O₃→CF₃O+2O₂ (4), CF₃O+O₃→CF₃O₂+O₂ (5). The upper limits were derived as k₄<0.5×10^-14 cm³ molecule^-1 s^-1, and k₅<1×10^-13 cm³ molecule^-1 s^-1. Results are discussed in the context of the atmospheric chemistry and ozone depletion by hydrofluorocarbons.