In limonene ozonolysis, the endocyclic double bond is inclined to generate hydroxy radicals, while the exocyclic double bond has a higher fraction of forming stabilized Criegee intermediates. The oxidation that happens on the exocyclic double bond greatly contributes to the organic peroxides, which account for a considerable proportion of secondary organic aerosol. Terpenes with multiple double bonds may have more complex effects on the atmosphere than previously thought.