Editing Freon (section)

==History==
The first CFCs were synthesized by [[Frédéric Swarts]] in the 1890s. In the late 1920s, a research team was formed by [[Charles Franklin Kettering]] in [[General Motors]] to find a replacement for the dangerous refrigerants then in use, such as [[ammonia]].<ref>{{Cite book |last=Cleveland |first=Cutler |title=Dictionary of Energy |publisher=Elsevier |year=2015 |isbn=978-0-08-096811-7 |edition=2nd |location=Amsterdam, Netherlands |pages=239}}</ref> The team was headed by [[Thomas Midgley Jr.]]<ref name=Sneader2005>{{cite book|title=Drug discovery: a history|chapter=Chapter 8: Systematic medicine|pages=74–87|author=Sneader W|publisher=John Wiley and Sons|location=Chichester, England|year=2005|isbn=978-0-471-89980-8|url=https://books.google.com/books?id=mYQxRY9umjcC&q=Drug+Discovery+history|access-date=2010-09-13}}</ref> In 1928, they improved the synthesis of CFCs and demonstrated their usefulness for such a purpose and their stability and nontoxicity. Kettering patented a refrigerating apparatus to use the gas; this was issued to [[Frigidaire]], a wholly owned subsidiary of [[General Motors]].<ref>{{cite web |title=Freon |url=http://inventors.about.com/library/inventors/blfreon.htm |archive-url=https://archive.today/20120710084411/http://inventors.about.com/library/inventors/blfreon.htm |url-status=dead |archive-date=July 10, 2012 |first=Mary |last=Bellis |publisher=About.com |series=Inventors |access-date=2013-04-30 }}</ref>

In 1930, General Motors and [[DuPont]] formed [[Kinetic Chemicals]] to produce Freon. Their product was [[dichlorodifluoromethane]] and is now designated "Freon-12", "R-12", or "CFC-12". The number after the R is a [[refrigerants#Classification of refrigerants|refrigerant class number]] developed by DuPont to systematically identify single halogenated hydrocarbons, as well as other refrigerants besides halocarbons.

Most uses of CFCs are now banned or severely restricted by the [[Montreal Protocol]] of August 1987, as they have been shown to be responsible for [[ozone depletion]].<ref>{{cite web |title=Handbook for the Montreal Protocol on Substances that Deplete the Ozone Layer - 7th Edition |year=2007 |url=http://ozone.unep.org/Publications/MP_Handbook/Section_1.2_Control_measures/Annex_A_-_Group_I.shtml |publisher=United Nations Environment Programme - Ozone Secretariat |access-date=2013-04-30 |archive-url=https://web.archive.org/web/20160530171422/http://ozone.unep.org/Publications/MP_Handbook/Section_1.2_Control_measures/Annex_A_-_Group_I.shtml |archive-date=2016-05-30 |url-status=dead }}</ref> Brands of Freon containing [[hydrofluorocarbon]]s (HFCs) instead have replaced many uses, but they, too, are under strict control under the [[Kyoto Protocol]], as they are deemed "super-greenhouse effect" gases.{{cn|date=May 2022}}