A system was developed to continuously quantify hexanal produced via lipid oxidation of oils at constant oxygen concentrations. Two kinetic models were derived from molecular mechanisms of oxidation to describe the initial (a cubic model) and accelerated (an extended model) stages of oxidation. The kinetic models illustrated the mechanistic influence of oxygen on rate constants and fit the data as well as simplistic curve fitting models. The monomolecular reaction phase showed the expected hyperbolic fit of inverse rate vs reciprocal oxygen concentration. The break point between initial and accelerated stages as function of oxygen concentration was represented by a logarithmic function.