Thomas Midgley, Jr. wuxuu abuuray gaaska ugu horeeya ee aan guban karin, oo aan sun ahayn ee loo yaqaan 'chlorofluorocarbon gas', Freon, sanadkii 1928. Magaca waa magac ganacsi oo ay leedahay shirkadda DuPont oo loogu talagalay wax kasta oo ah chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), ama hydrofluorocarbon (HFC) qaboojiye. Magacyada qaboojiyaha waxaa ka mid ah lambar tilmaamaya isku-darka molikiyuulka (tusaale ahaan, R-11, R-12, R-22, R-134A). Isku-darka ugu badan ee loo isticmaalo ballaarinta tooska ah ee guriga iyo qaboojinta raaxada dhismaha waa HFC oo loo yaqaan 'Chlorofluoromethane-2' (Rodifluoromethane-22).
Qaab dhismeedka molecule