A pulse radiolysis technique has been used to investigate the UV absorption spectrum of the CH₃CF₂CH₂O₂ radical from HFC-272ca, CH₃CF₂CH₃. The absorption cross sections were quantified in the wavelength range 220-320 nm; at 250 nm the absorption cross section for CH₃CF₃CH₂O₂ was σ = (451 ± 59) × 10^-20 cm² molecule^-1. By following the increase in NO₂ at 400 nm, the rate constant for the reaction of CH₃CF₂CH₂O₂ with NO was determined to be (8.5 ± 1.9) × 10^-12 cm³ molecule^-1 s^-1. The reaction of CH₃CF₂CH₂O₂ with NO₂ was found to have a reaction rate constant of (6.8 ± 0.5) × 10^-12 cm³ molecule^-1 s^-1. The kinetics of the reaction of CH₃CF₂CH₃ with F atoms and CH₃CF₂CH₂ with O₂ were studied. The rate constants were (2.8 ± 0.9) × 10^-11 and (1.10 ± 0.03) × 10^-12 cm³ molecule^-1 s^-1, respectively. The observed rate constant for the self-reaction of CH₃CF₂CH₂O₂ radicals was (8.6 ± 0.4) × 10^-12 cm³ molecule^-1 s^-1. The reaction of CH₃CF₂CH₂O₂ radicals with NO gives CH₃CF₂CH₂O radicals; the dominant atmospheric fate of CH₃CF₂CH₂O radicals is reaction with O₂ to give CH₃CF₂CHO. As part of the present work, relative rate techniques were used to measure rate constants at 296 ± 2 K for the reactions of Cl and F atoms with CH₃CF₂CH₃, with the values being (1.7 ± 0.2) × 10^-14 and (3.3 ± 0.8) × 10^-11 cm³ molecule^-1 s^-1, respectively.