The rate constants for the gas-phase reactions of di-ferl-butyl ether (DTBE) with chlorine atoms, hydroxyl radicals, and nitrate radicals have been determined in relative rate experiments using FTIR spectroscopy Values of _(DTBE→C1) = (1.4 ±0.2) × 10^-10, K_(DTBE+OH) = (3.7 ±0.7) × 10^-12. and K_(DTBE+NO3) = (2.8 ±0.9) × 10^-16 cm³ molecule^-11 s^-1 were obtained. Tert-butyl acetate was identified as the major product of both Cl atom and OH radical initiated oxidation of DTBE in air in the presence of NO₃ The molar tert-butyl acetate yield was 0.85 ±.0.11 in the Cl atom experiments and 0.84 ±0.11 in OH radical experiments As part of this work the rate constant for reaction of Cl atoms with terl-butyl acetate at 295 K was determined to be (1.6 ±0.3) × 10^-11 cm³ molecule ¹s^-1. The stated errors are two standard deviations (2σ)