Absolute rate constants for the reaction of ethyl tert-butyl, diisopropyl, and methyl tert-amyl ethers with the hydroxyl radical, hydrated electron, and hydrogen atom in water have been determined using electron pulse radiolysis (e(aq)(-) and . OH), absorption spectroscopy (e(aq)(-) and . OH), and EPR free induction decay attenuation (H) measurements. At room temperature the hydroxyl radical reaction was found to be the primary loss pathway, with fate constants of (1.81 +/- 0.09) x 10(9), (2.49 +/- 0.12) x 10(9), and (2.37 +/- 0.12) x 10(9) dm(3) mol(-1) s(-1) determined for these ethers, respectively. The reaction of the hydrated electron with these compounds was not significant, with upper limit values of less than or equal to 10(7), less than or equal to6.7 x 10(6), and less than or equal to4.0 x 10(6) dm(3) mol(-1) s(-1) determined. The corresponding rate constants for hydrogen atom reaction with these ethers were (7.04 +/- 0.11) x 10(6), (6.70 +/- 0.09) x 10(7), and (3.09 +/- 0.09) x 10(6) dm(3) mol(-1) s(-1). On the basis of these rate constant values, the kinetic computer modeling of the free-radical removal of these ethers from NaO-saturated aqueous solution was found to be in very good agreement with experimental steady-state, Co-60, irradiation measurements.