As it becomes more difficult for the supply of petroleum to keep up with its demand, alternative sources for chemicals derived from petroleum must be identified. A large fraction of these chemicals could be produced using lipids from renewable feedstocks such as vegetable oils, animal fats, and bacterial lipids. For example, many lipid sources contain unsaturated fatty acids, which can be oxidized to form a variety of products such as diacids and epoxides. These chemicals are used to formulate herbicides, detergents, plasticizers, lubricants, paints, and other useful products. One of the most common unsaturated fatty acids is oleic acid, and it can be oxidized with ozone to produce azelaic acid (a diacid) and pelargonic acid (a monoacid). In this paper, a kinetic analysis of oleic acid oxidation in a supercritical carbon dioxide medium was performed, and the results were compared to performing the reaction in the absence of a supercritical fluid. In particular, the effect of the supercritical fluid on reaction rate, reaction products, and selectivity was determined. Oxidizers such as ozone and hydrogen peroxide were used to investigate the variety of products that could be formed.