To assess the contribution of oxidation to the overall degradation of compounds in the environment, it would be helpful to have QSAR models which cover a large range of chemicals and/or degradation processes. At present QSAR models for oxidation in the aqueous environment mainly deal with phenols and are restricted to a specific reaction with one oxidant present in the aqueous environment. In this paper we have gathered data on oxidation of phenols with various aqueous phase oxidants to compare the different processes. It is shown that existing models for oxidation can be extended by using the energy of the highest occupied molecular orbital calculated with semiempirical molecular orbital methods as a descriptor. The results from correlating reaction rate constants with this theoretical descriptor are equal to results using experimentally measured half-wave potentials. By using PLS analysis on those compounds having multiple response data, a single model comprising all oxidation rate constants with different oxidants is created. This analysis shows that for four out of five oxidants the electronic properties of the compound determine the reaction rate constants. These oxidants are thought to react by the same mechanism, namely outer-sphere one-electron oxidation. The fifth oxidant, potassium dichromate, shows a different dependence on the descriptor variables, indicating a different reaction mechanism.