Chlorotrifluoromethane, R-13, CFC-13, or Freon 13, is a non-flammable, non-corrosive, nontoxic chlorofluorocarbon (CFC) and also a mixed halomethane. It is a man-made substance used primarily as a refrigerant. When released into the environment, CFC-13 has a high ozone depletion potential, and long atmospheric lifetime. Only a few other greenhouse gases surpass CFC-13 in global warming potential (GWP). The IPCC AR5 reported that CFC-13's atmospheric lifetime was 640 years.
CFC-13like all chlorofluorocarbon compoundscontains atoms of carbon (C), chlorine (Cl), and fluorine (F).
It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride:
This reaction can also produce trichlorofluoromethane (CCl<sub>3</sub>F), dichlorodifluoromethane (CCl<sub>2</sub>F<sub>2</sub>) and tetrafluoromethane (CF<sub>4</sub>).
Following the unanimous ratification of the 1987 Montreal Protocolin response to concerns about the role of concentrations of chlorofluorocarbons (CFCs) in ozone layer-depletion in the stratospherea process was put into place to gradually phase out and replace CFC-13 and all the other CFCs. Research in the 1980s said that these man-made CFC compounds had opened a hole in ozone layer in the upper atmosphere or stratosphere that protects life on earth from UV radiation.
CFC-13's ozone depletion potential (ODP) is high 1 (CCl<sub>3</sub>F = 1)it is categorized as a Class I in the IPCC's list of ozone-depleting substances. CFC-13's radiative efficiency is high which results in a high global warming potential (GWPs) of 13 900 GWP-100 yr that is "surpassed by very few other greenhouse gases." It is categorized as a Class I in the list of ozone-depleting Substances.
Starting in the 2010s, despite a global ban on the production of CFCs, five of these ozone-damaging emissions were on the rise.
The atmospheric abundance of CFC-13 rose from 3.0 parts per trillion (ppt) in year 2010 to 3.3 ppt in year 2020 based on analysis of air samples gathered from sites around the world. Contrary to the Montreal Protocol, the atmospheric emissions of CFC-13 and four other chlorofluorocarbons (CFCs), increased between 2010 and 2020.
As of 2023, the drivers behind the increase in CFC-13 and CFC-112a emissions were not certain.
The IPCC AR5 reported that CFC-13's Atmospheric lifetime was 640 years.