Editing Chlorofluorocarbon (section)

===Regulation===
Since the late 1970s, the use of CFCs has been heavily regulated because of their destructive effects on the [[Ozone depletion|ozone layer]]. After the development of his [[electron capture detector]], [[James Lovelock]] was the first to detect the widespread presence of CFCs in the air, finding a [[mole fraction]] of 60 [[parts per trillion|ppt]] of CFC-11 over [[Ireland]]. In a self-funded research expedition ending in 1973, Lovelock went on to measure CFC-11 in both the Arctic and Antarctic, finding the presence of the gas in each of 50 air samples collected, and concluding that CFCs are not hazardous to the environment. The experiment did however provide the first useful data on the presence of CFCs in the atmosphere. The damage caused by CFCs was discovered by [[Sherry Rowland]] and [[Mario Molina]] who, after hearing a lecture on the subject of Lovelock's work, embarked on research resulting in the first publication suggesting the connection in 1974. It turns out that one of CFCs' most attractive features—their low reactivity—is key to their most destructive effects. CFCs' lack of reactivity gives them a lifespan that can exceed 100 years, giving them time to diffuse into the upper [[stratosphere]].<ref>{{cite journal|last1=Lee|first1=Bing-Sun|last2=Chiou|first2=Chung-Biau|title=The Relationship of Meteorological and Anthropogenic Factors to Time Series Measurements of CFC-11, CFC-12, and CH3CCl3 Concentrations in the Urban Atmosphere|journal=Atmospheric Environment|date=October 2008|volume=42|issue=33|page=7707|doi=10.1016/j.atmosenv.2008.05.042|bibcode=2008AtmEn..42.7706L}}</ref> Once in the stratosphere, the sun's [[ultraviolet]] radiation is strong enough to cause the [[homolysis (chemistry)|homolytic]] cleavage of the C-Cl bond. In 1976, under the Toxic Substances Control Act, the EPA banned commercial manufacturing and use of CFCs and aerosol propellants. This was later superseded in the 1990 amendments to the Clean Air Act to address stratospheric ozone depletion.<ref>{{cite report |last1=Auer |first1=Charles |first2=Frank |last2=Kover |first3=James |last3=Aidala |first4=Marks |last4=Greenwood |date=1 March 2016 |title=Toxic Substances: A Half Century of Progress |publisher=EPA Alumni Association |url=https://www.epaalumni.org/userdata/pdf/toxics.pdf }}</ref>

[[File:Future ozone layer concentrations.jpg|thumb|upright=1.20|alt=An animation showing colored representation of ozone distribution by year, above North America, through 6 steps. It starts with a lot of ozone especially over Alaska and by 2060 is almost all gone from north to south.|NASA projection of stratospheric ozone, in [[Dobson unit]]s, if chlorofluorocarbons had not been banned. [[:File:Future ozone layer concentrations.gif|Animated version]].]]

By 1987, in response to a dramatic seasonal depletion of the ozone layer over [[Antarctica]], diplomats in [[Montreal]] forged a treaty, the [[Montreal Protocol]], which called for drastic reductions in the production of CFCs. On 2 March 1989, 12 [[European Community]] nations agreed to ban the production of all CFCs by the end of the century. In 1990, diplomats met in [[London]] and voted to significantly strengthen the Montreal Protocol by calling for a complete elimination of CFCs by 2000. By 2010, CFCs should have been completely eliminated from developing countries as well.
[[File:Ozone cfc trends.png|class=skin-invert-image|left|thumb|upright=1.5|Ozone-depleting gas trends]]
Because the only CFCs available to countries adhering to the treaty is from recycling, their prices have increased considerably. A worldwide end to production should also terminate the smuggling of this material. However, there are current CFC smuggling issues, as recognized by the [[United Nations Environmental Programme]] (UNEP) in a 2006 report titled "Illegal Trade in Ozone Depleting Substances". UNEP estimates that between 16,000–38,000 tonnes of CFCs passed through the black market in the mid-1990s. The report estimated between 7,000 and 14,000 tonnes of CFCs are smuggled annually into developing countries. Asian countries are those with the most smuggling; as of 2007, China, India and South Korea were found to account for around 70% of global CFC production,<ref>{{cite book |title=Illegal Trade in Ozone Depleting Substances |date=2007 |publisher=[[United Nations Environmental Programme]] |isbn=978-92-807-2815-6 |url=http://www.mea-ren.org/files/publications/Illegal%20Trade%20in%20ODS.pdf |archive-url=https://web.archive.org/web/20120322071146/http://www.mea-ren.org/files/publications/Illegal%20Trade%20in%20ODS.pdf |archive-date=22 March 2012 }}{{pn|date=June 2024}}</ref> South Korea later to ban CFC production in 2010.<ref>{{cite news |title=S. Korea to ban import, production of freon, halon gases in 2010 |url=https://en.yna.co.kr/view/AEN20091222006700320 |work=Yonhap |date=23 December 2009 }}</ref> Possible reasons for continued CFC smuggling were also examined: the report noted that many of the refrigeration systems that were designed   to be operated utilizing the banned CFC products have long lifespans and continue to operate. The cost of replacing the equipment of these items is sometimes cheaper than outfitting them with a more ozone-friendly appliance. Additionally, CFC smuggling is not considered a significant issue, so the perceived penalties for smuggling are low. In 2018 public attention was drawn to the issue, that at an unknown place in east Asia an estimated amount of 13,000 metric tons annually of CFCs have been produced since about 2012 in violation of the protocol.<ref>{{cite news|title=Ozonkiller: Ein verbotener Stoff in der Atmosphäre – WELT|periodical=Welt.de|date=16 May 2018|url=https://www.welt.de/wissenschaft/article176426312/Ozonkiller-Ein-verbotener-Stoff-in-der-Atmosphaere.html|access-date=2018-05-18|language=de|archive-date=2020-10-05|archive-url=https://web.archive.org/web/20201005190707/https://www.welt.de/wissenschaft/article176426312/Ozonkiller-Ein-verbotener-Stoff-in-der-Atmosphaere.html/|url-status=live}}</ref><ref>{{cite web|title=Ozone hole-forming chemical emissions increasing and mysterious source in East Asia may be responsible|periodical=Independent.co.uk|date=16 May 2018|url=https://www.independent.co.uk/environment/ozone-hole-chemicals-cfc-increase-mystery-source-east-asia-antarctica-a8354481.html|access-date=2018-05-18|archive-date=2020-11-09|archive-url=https://web.archive.org/web/20201109025914/https://www.independent.co.uk/environment/ozone-hole-chemicals-cfc-increase-mystery-source-east-asia-antarctica-a8354481.html|url-status=live}}</ref> While the eventual phaseout of CFCs is likely, efforts are being taken to stem these current non-compliance problems.

By the time of the [[Montreal Protocol]], it was realised that deliberate and accidental discharges during system tests and maintenance accounted for substantially larger volumes than emergency discharges, and consequently halons were brought into the treaty, albeit with many exceptions.<ref>{{cite web | title=Halon essential use exemptions | website=DCCEEW | date=23 February 2023 | url=https://www.dcceew.gov.au/environment/protection/ozone/halon/essential-use-exeptions | access-date=17 May 2024}}</ref><ref>{{Cite web |title={{!}} Ozone Secretariat |url=https://ozone.unep.org/halon-aviation |access-date=2023-12-12 |website=ozone.unep.org}}</ref><ref>{{Cite web |title=Phase out of Halons : Firesafe.org.uk |url=https://www.firesafe.org.uk/phase-out-of-halons/ |access-date=2023-12-12 |website=www.firesafe.org.uk}}</ref>

====Regulatory gap====
While the production and consumption of CFCs are regulated under the Montreal Protocol, emissions from existing banks of CFCs are not regulated under the agreement. In 2002, there were an estimated 5,791 kilotons of CFCs in existing products such as refrigerators, air conditioners, aerosol cans and others.<ref>Campbell, Nick ''et al.'' [https://web.archive.org/web/20140923002205/http://www.ipcc.ch/pdf/special-reports/sroc/sroc11.pdf "HFCs and PFCs: Current and Future Supply, Demand and Emissions, plus Emissions of CFCs, HCFCs and Halons"], Ch. 11 in ''IPCC/TEAP Special Report: Safeguarding the Ozone Layer and the Global Climate System''</ref> Approximately one-third of these CFCs are projected to be emitted over the next decade{{when|date=March 2024}} if action is not taken, posing a threat to both the ozone layer and the climate.<ref>[http://www.eesi.org/100209_cfc Chlorofluorocarbons: An Overlooked Climate Threat, EESI Congressional Briefing]. {{webarchive|url=https://web.archive.org/web/20091204120541/http://www.eesi.org/100209_cfc |date=2009-12-04 }}. Eesi.org. Retrieved on 24 September 2011.</ref> A proportion of these CFCs can be safely captured and destroyed by means of high temperature, controlled incineration which destroys the CFC molecule.<ref>{{Cite web |last= |title=The cool way to destroy CFCs |url=https://www.newscientist.com/article/mg14920143-600-the-cool-way-to-destroy-cfcs/ |access-date=2023-12-12 |website=New Scientist |language=en-US}}</ref>

====Regulation and DuPont====
In 1978 the United States banned the use of CFCs such as Freon in aerosol cans, the beginning of a long series of regulatory actions against their use. The critical DuPont manufacturing patent for Freon ("Process for Fluorinating Halohydrocarbons", U.S. Patent #3258500) was set to expire in 1979. In conjunction with other industrial peers DuPont formed a lobbying group, the "Alliance for Responsible CFC Policy", to combat regulations of ozone-depleting compounds.<ref>{{cite book |last1=DeSombre |first1=Elizabeth R. |title=Domestic Sources of International Environmental Policy: Industry, Environmentalists, and U.S. Power |date=2000 |publisher=MIT Press |isbn=978-0-262-04179-9 |page=93 }}</ref> In 1986 DuPont, with new patents in hand, reversed its previous stance and publicly condemned CFCs.<ref name="Ethics">{{cite journal |last1=Smith |first1=Brigitte |title=Ethics of Du Pont's CFC Strategy 1975–1995 |journal=Journal of Business Ethics |date=1998 |volume=18 |issue=1 |pages=103–114 |doi=10.1023/A:1005789810145 }}</ref> DuPont representatives appeared before the [[Montreal Protocol]] urging that CFCs be banned worldwide and stated that their new HCFCs would meet the worldwide demand for refrigerants.<ref name="Ethics"/>