The reactions of O(3P) with CH3OH and C2H5OH were studied as a function of temperature. The absolute rate constants for these reactions fit the following expressions:[Formula: see text](Activation energies are in kJ/mol. Rate constants are in 1 mol−1 s−1.) The data support abstraction of the α-H atom as the primary step. The α-C—H bond in ethanol is apparently weaker than that in methanol, and this alters the nature of subsequent steps in the mechanisms for these reactions. The presence of oxygen alters the stoichiometric coefficients for these reactions and produces the corresponding carboxylic acid.