The objective of this study was to compare the sooting behavior of lactones to other hydrocarbons under well-defined burning conditions. Engine experiments suggest that lactones can reduce particulate emissions , so sugar-derived lactone biofuels could have the significant co-benefit of improving local air quality as well as reducing net carbon emissions. However, laboratory-scale sooting tendencies have not been reported for them. Lactones would be expected to have low sooting tendencies since they contain two oxygen atoms, but they also contain a ring, which tends to promote soot production. Furthermore, both oxygen atoms are bonded to the same carbon atom, so they could directly form CO2, which would use the oxygen atoms inefficiently to sequester only one carbon atom .