Editing Propellant (section)

====Propellant compounds====
[[Chlorofluorocarbon]]s (CFCs) were once often used as propellants,<ref>{{cite magazine
| author     =<!--Staff writer(s); no by-line.-->
| title      = Fires Halted Quickly by "Lazy" Freon Gas
| url        = https://books.google.com/books?id=zt4DAAAAMBAJ&q=%22Freon%22&pg=PA115
| magazine   = [[Popular Mechanics]]
| quote = Freon chemical compounds in household refrigerators, air-cooling systems and as '''a [[DDT]] carrier in aerosol [[Fogger#Fogger composition|insect bombs]]''' have been found to be more effective in extinguishing fires than carbon dioxide.
| volume = 87
| page =  115
| publisher  = [[Hearst Communications|Hearst Magazines]]
| date       = April 1947
| access-date= June 7, 2019
}}</ref> but since the [[Montreal Protocol]] came into force in 1989, they have been replaced in nearly every country due to the negative effects CFCs have on Earth's [[ozone layer]]. The most common replacements  of CFCs are mixtures of volatile [[hydrocarbon]]s, typically [[propane]], n-[[butane]] and [[isobutane]].<ref>{{Cite journal|last1=Yeoman|first1=Amber M.|last2=Lewis|first2=Alastair C. |date= 2021-04-22 |title=Global emissions of VOCs from compressed aerosol products|url=https://eprints.whiterose.ac.uk/172292/18/elementa.2020.20.00177.pdf |journal= Elementa: Science of the Anthropocene|language=en|volume=9|issue=1|pages=00177|doi=10.1525/elementa.2020.20.00177|issn=2325-1026|doi-access=free}}</ref> [[Dimethyl ether]] (DME) and [[methyl ethyl ether]] are also used. All these have the disadvantage of being [[flammable]]. [[Nitrous oxide]] and [[carbon dioxide]] are also used as propellants to deliver foodstuffs (for example, [[whipped cream]] and [[cooking spray]]). Medicinal aerosols such as [[asthma inhaler]]s use [[hydrofluoroalkanes]] (HFA): either [[HFA 134a]] (1,1,1,2,-tetrafluoroethane) or [[HFA 227]] (1,1,1,2,3,3,3-heptafluoropropane) or combinations of the two. More recently, liquid [[hydrofluoroolefin]] (HFO) propellants have become more widely adopted in aerosol systems due to their relatively low vapor pressure, low [[global warming potential]] (GWP), and nonflammability.<ref>{{Cite web|url=https://prod-edam.honeywell.com/content/dam/honeywell-edam/pmt/oneam/en-us/medical-propellant1/documents/pmt-am-solstice-propellant-DataSheet.pdf|title=Solstice® Propellant Technical Bulletin|website=Honeywell|date = 2017}}</ref>