Editing Bromine (section)

==Applications==
A wide variety of organobromine compounds are used in [[Industry (manufacturing)|industry]]. Some are prepared from bromine and others are prepared from [[hydrogen bromide]], which is obtained by burning [[hydrogen]] in bromine.<ref name="Ullmann">{{Cite book|author=Mills, Jack F. |title=Bromine: in Ullmann's Encyclopedia of Chemical Technology|publisher= Wiley-VCH Verlag|location= Weinheim|date= 2002|doi=10.1002/14356007.a04_391|chapter=Bromine|isbn=978-3527306732}}</ref>

===Flame retardants===
[[File:Tetrabromobisphenol A.svg|thumb|left|Tetrabromobisphenol A]]

[[Brominated flame retardant]]s represent a commodity of growing importance, and make up the largest commercial use of bromine. When the brominated material burns, the flame retardant produces [[hydrobromic acid]] which interferes in the radical [[chain reaction]] of the [[oxidation]] reaction of the fire. The mechanism is that the highly reactive hydrogen radicals, oxygen radicals, and [[hydroxyl radical]]s react with hydrobromic acid to form less reactive bromine radicals (i.e., free bromine atoms). Bromine atoms may also react directly with other radicals to help terminate the free radical chain-reactions that characterise combustion.<ref>{{Cite journal|journal = Journal of Fire Sciences|volume = 14|pages = 426–442| date = 1996|doi = 10.1177/073490419601400602|title = Mechanisms for Flame Retardancy and Smoke suppression – A Review|first =Joseph|last = Green|issue = 6 |s2cid = 95145090}}</ref><ref>{{Cite journal|journal = Polymer Degradation and Stability|volume = 77|date = 2002|pages = 325–331| doi = 10.1016/S0141-3910(02)00067-8|title = Fire retardant mechanism of aliphatic bromine compounds in polystyrene and polypropylene|first = Jelle|last = Kaspersma|author2 = Doumena, Cindy|author3 = Munrob Sheilaand|author4 = Prinsa, Anne-Marie|issue = 2}}</ref>

To make brominated polymers and plastics, bromine-containing compounds can be incorporated into the polymer during [[polymerisation]]. One method is to include a relatively small amount of brominated monomer during the polymerisation process. For example, [[vinyl bromide]] can be used in the production of [[polyethylene]], [[polyvinyl chloride]] or [[polypropylene]]. Specific highly brominated molecules can also be added that participate in the polymerisation process. For example, [[tetrabromobisphenol A]] can be added to [[polyester]]s or epoxy resins, where it becomes part of the polymer. Epoxies used in [[printed circuit board]]s are normally made from such flame retardant [[resin]]s, indicated by the FR in the abbreviation of the products ([[FR-4]] and [[FR-2]]). In some cases, the bromine-containing compound may be added after polymerisation. For example, [[decabromodiphenyl ether]] can be added to the final polymers.<ref>{{Cite journal|journal = Journal of Fire Sciences|volume = 22|pages = 25–40| date = 2004|doi = 10.1177/0734904104038107|title = A Review of Current Flame Retardant Systems for Epoxy Resins|first = Edward D.|last = Weil|author2=Levchik, Sergei|s2cid = 95746728}}</ref>

A number of gaseous or highly volatile brominated [[halomethane]] compounds are non-toxic and make superior fire suppressant agents by this same mechanism, and are particularly effective in enclosed spaces such as submarines, airplanes, and spacecraft. However, they are expensive and their production and use has been greatly curtailed due to their effect as ozone-depleting agents. They are no longer used in routine fire extinguishers, but retain niche uses in aerospace and military automatic fire suppression applications. They include [[bromochloromethane]] (Halon 1011, CH{{sub|2}}BrCl), [[bromochlorodifluoromethane]] (Halon 1211, CBrClF{{sub|2}}), and [[bromotrifluoromethane]] (Halon 1301, CBrF{{sub|3}}).<ref name="UllmannF">Siegemund, Günter; Schwertfeger, Werner; Feiring, Andrew; Smart, Bruce; Behr, Fred; Vogel, Herward; McKusick, Blaine (2002) "Fluorine Compounds, Organic" Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a11_349}}</ref>

===Other uses===
[[File:Bromo-Seltzer_Tower_MD2.jpg|thumb|upright|Baltimore's [[Emerson Bromo-Seltzer Tower]], originally part of the headquarters of Emerson Drug Company, which made [[Bromo-Seltzer]]]]
[[Silver bromide]] is used, either alone or in combination with [[silver chloride]] and [[silver iodide]], as the light sensitive constituent of [[photographic emulsion]]s.<ref name="Greenwood798" />

[[1,2-Dibromoethane|Ethylene bromide]] was an [[Gasoline additive|additive in gasolines]] containing lead anti-[[engine knocking]] agents. It scavenges lead by forming volatile lead bromide, which is exhausted from the engine. This application accounted for 77% of the bromine use in 1966 in the US. This application has declined since the 1970s due to environmental regulations (see below).<ref>{{Cite journal|journal = Environment International|volume = 29|date = 2003| doi = 10.1016/S0160-4120(03)00121-1|title = An overview of commercially used brominated flame retardants, their applications, their use patterns in different countries/regions and possible modes of release|first = Mehran|last = Alaeea|author2 = Ariasb, Pedro|author3 = Sjödinc, Andreas|author4 = Bergman, Åke|issue = 6|pmid=12850087|pages = 683–9| bibcode=2003EnInt..29..683A }}</ref>

[[Brominated vegetable oil]] (BVO), a complex mixture of plant-derived triglycerides that have been reacted to contain atoms of the element bromine bonded to the molecules, is used primarily to help emulsify citrus-flavored soft drinks, preventing them from separating during distribution.

Poisonous [[bromomethane]] was widely used as [[pesticide]] to [[Fumigation|fumigate]] soil and to fumigate housing, by the tenting method. Ethylene bromide was similarly used.<ref name="USGSYB2007" /> These volatile organobromine compounds are all now regulated as [[ozone depletion]] agents. The [[Montreal Protocol|Montreal Protocol on Substances that Deplete the Ozone Layer]] scheduled the phase out for the [[ozone depleting]] chemical by 2005, and organobromide pesticides are no longer used (in housing fumigation they have been replaced by such compounds as [[sulfuryl fluoride]], which contain neither the chlorine or bromine organics which harm ozone). Before the Montreal protocol in 1991 (for example) an estimated 35,000 tonnes of the chemical were used to control [[nematode]]s, [[fungi]], [[weed]]s and other soil-borne diseases.<ref>{{cite web|title = Alternatives to Methyl Bromide for the Control of Soil-Borne Diseases and Pests in California|first = Belinda|last = Messenger|author2 = Braun, Adolf|date = 2000|publisher = Pest Management Analysis and Planning Program|url = https://www.cdpr.ca.gov/docs/emon/methbrom/alt-anal/sept2000.pdf|access-date = 2008-11-17|archive-url = https://web.archive.org/web/20100421041145/https://www.cdpr.ca.gov/docs/emon/methbrom/alt-anal/sept2000.pdf|archive-date = 2010-04-21|url-status = dead}}</ref><ref>{{Cite journal|title = Economics of the "Critical Use" of Methyl bromide under the Montreal Protocol|doi = 10.1093/cep/byi028|journal =Contemporary Economic Policy|volume = 23|pages = 376–393|date = 2008|first = Stephen J.|last = Decanio|author2=Norman, Catherine S.|issue = 3}}</ref>

In pharmacology, inorganic [[bromide]] compounds, especially [[potassium bromide]], were frequently used as general sedatives in the 19th and early 20th century. Bromides in the form of simple salts are still used as anticonvulsants in both veterinary and human medicine, although the latter use varies from country to country. For example, the U.S. [[Food and Drug Administration]] (FDA) does not approve bromide for the treatment of any disease, and [[sodium bromide]] was removed from over-the-counter sedative products like [[Bromo-Seltzer]], in 1975.<ref>{{cite book|author=Adams, Samuel Hopkins |title=The Great American fraud|url=https://archive.org/details/greatamericanfr03adamgoog|access-date=2011-06-25 |date=1905|publisher=Press of the American Medical Association}}</ref> Commercially available organobromine pharmaceuticals include the vasodilator [[nicergoline]], the sedative [[brotizolam]], the anticancer agent [[pipobroman]], and the antiseptic [[merbromin]]. Otherwise, organobromine compounds are rarely pharmaceutically useful, in contrast to the situation for [[organofluorine chemistry|organofluorine compounds]]. Several drugs are produced as the bromide (or equivalents, hydrobromide) salts, but in such cases bromide serves as an innocuous counterion of no biological significance.<ref name="KO" />

Other uses of organobromine compounds include high-density drilling fluids, dyes (such as [[Tyrian purple]] and the indicator [[bromothymol blue]]), and pharmaceuticals. Bromine itself, as well as some of its compounds, are used in water treatment, and is the precursor of a variety of inorganic compounds with an enormous number of applications (e.g. [[silver bromide]] for photography).<ref name="Greenwood798" /> [[Zinc–bromine battery|Zinc–bromine batteries]] are hybrid [[Flow battery|flow batteries]] used for stationary electrical power backup and storage; from household scale to industrial scale.

Bromine is used in cooling towers (in place of chlorine) for controlling bacteria, algae, fungi, and [[zebra mussel]]s.<ref>Buecker, Brad (1998-01-07) [https://www.power-eng.com/emissions/choose-the-right-cooling-tower-chemicals/#gref Choose the Right Cooling Tower Chemicals]. ''Power Engineering''. {{Webarchive|url=https://web.archive.org/web/20210810000356/https://www.power-eng.com/emissions/choose-the-right-cooling-tower-chemicals/#gref|date=10 August 2021}} Choose the Right Cooling Tower Chemicals | Power Engineering |1998</ref>

Because it has similar antiseptic qualities to chlorine, bromine can be used in the same manner as chlorine as a disinfectant or antimicrobial in applications such as swimming pools. Bromine came into this use in the United States during [[World War II]] due to a predicted shortage of chlorine.<ref>{{Cite journal |last1=VanderVelde |first1=T. L. |last2=Mallmann |first2=W. L. |last3=Moore |first3=A. V. |date=1948 |title=A Comparative Study Of Chlorine And Bromine For Swimming Pool Disinfection |url=https://www.jstor.org/stable/26324332 |journal=The Sanitarian |volume=11 |issue=2 |pages=47–52 |jstor=26324332 |pmid=18891247 |issn=0096-560X}}</ref> However, bromine is usually not used outside for these applications due to it being relatively more expensive than chlorine and the absence of a stabilizer to protect it from the sun. For indoor pools, it can be a good option as it is effective at a wider pH range. It is also more stable in a heated pool or hot tub.<ref>{{Cite book |last=Blanchard |first=Kristine |title=Pool Care For Dummies |date=2023 |publisher=John Wiley and Sons |isbn=978-1-394-16611-4 |edition=1st |location=Indianapolis |pages=259–260}}</ref>