" PRELIMINARY ATMOSPHERIC MONITORING DATA from a remote South Korean island off China’s east coast shows elevated concentrations of hydrofluorocarbon-23, or HFC-23, a greenhouse gas 14,700 times more potent than carbon dioxide on a pound-for-pound basis, according to the World Meteorological Association. The primary source of HFC-23 emissions in China was as a byproduct in the manufacturing of hydrochlorofluorocarbon-22, which is used to produce other fluorinated chemicals including polytetrafluoroethylene, or Teflon. " https://undark.org/2023/11/28/china-hfc-23/