Chlorofluorocarbons (CFC-11 thiab CFC-12), lawv kuj yog tshuaj lom neeg hauv troposphere, tab sis lawv kuj tuaj yeem tso duab rau hauv stratosphere los ntawm hnub ci hluav taws xob lossis noj los ntawm cov tshuaj tiv thaiv nrog cov pa oxygen atoms.
CCl₃F + hv → CCl₂F + Cl,
CCl₂F₂ + hv → CClF₂ + Cl
CCl₃F + O (1D) → CCl₂F + ClO
CCl₂F₂ + O (1D) → CClF + ClO