Editing Potassium nitrate (section)

==Uses==
Potassium nitrate has a wide variety of uses, largely as a source of nitrate.

===Nitric acid production===
Historically, [[nitric acid]] was produced by combining sulfuric acid with nitrates such as saltpeter. In modern times this is reversed: nitrates are produced from nitric acid produced via the [[Ostwald process]].

===Oxidizer===
[[File:10. Оксидација на јагленче во стопен калиум нитрат.webm|thumb|right|A demonstration of the oxidation of a piece of [[charcoal]] in molten potassium nitrate]]
The most famous use of potassium nitrate is probably as the oxidizer in [[gunpowder|blackpowder]]. From the most ancient times until the late 1880s, blackpowder provided the explosive power for all the world's firearms. After that time, small arms and large artillery increasingly began to depend on [[cordite]], a [[smokeless powder]]. Blackpowder remains in use today in [[black powder rocket motor]]s, but also in combination with other fuels like sugars in "[[rocket candy]]" (a popular amateur rocket propellant). It is also used in fireworks such as [[smoke bomb]]s.<ref>[http://www.galleries.com/minerals/carbonat/niter/niter.htm Amthyst Galleries, Inc] {{webarchive|url=https://web.archive.org/web/20081104110741/http://www.galleries.com/minerals/carbonat/niter/niter.htm |date=2008-11-04}}. Galleries.com. Retrieved on 2012-03-07.</ref> It is also added to cigarettes to maintain an even burn of the tobacco<ref>[http://tobaccodocuments.org/product_design/00382055-2062.html Inorganic Additives for the Improvement of Tobacco] {{webarchive|url=https://web.archive.org/web/20071101110019/http://tobaccodocuments.org/product_design/00382055-2062.html |date=2007-11-01}}, TobaccoDocuments.org</ref> and is used to ensure complete combustion of [[paper cartridge]]s for cap and ball revolvers.<ref>{{cite book |author=Kirst, W.J. |title=Self Consuming Paper Cartridges for the Percussion Revolver |place=Minneapolis, Minnesota |publisher=Northwest Development Co. |year=1983}}</ref> It can also be heated to several hundred degrees to be used for [[Bluing (steel)#Niter bluing|niter bluing]], which is less durable than other forms of protective oxidation, but allows for specific coloration of steel parts, such as screws, pins, and other small parts of firearms.

===Meat processing===
Potassium nitrate has been a common ingredient of salted meat since [[Antiquity of humanity|antiquity]]<ref>{{Cite journal|last1=Binkerd|first1=E. F|last2=Kolari|first2=O. E|date=1975-01-01|title=The history and use of nitrate and nitrite in the curing of meat|journal=Food and Cosmetics Toxicology|volume=13|issue=6|pages=655–661|doi=10.1016/0015-6264(75)90157-1|issn=0015-6264|pmid=1107192}}</ref> or the [[Middle Ages]].<ref>[https://web.archive.org/web/20031223155710/http://www.uwex.edu/ces/flp/meatscience/sausage.html "Meat Science"], University of Wisconsin. uwex.edu.</ref> The widespread adoption of nitrate use is more recent and is linked to the development of large-scale meat processing.<ref name="auto1" /> The use of potassium nitrate has been mostly discontinued because it gives slow and inconsistent results compared with [[sodium nitrite]] preparations such as "Prague powder" or pink "[[curing salt]]". Even so, potassium nitrate is still used in some food applications, such as salami, dry-cured ham, [[charcuterie]], and (in some countries) in the [[brine]] used to make [[corned beef]] (sometimes together with sodium nitrite).<ref>[http://www.foodnetwork.com/food/recipes/recipe/0,,FOOD_9936_36271,00.html Corned Beef] {{webarchive|url=https://web.archive.org/web/20080319080839/http://www.foodnetwork.com/food/recipes/recipe/0,,FOOD_9936_36271,00.html |date=2008-03-19}}, Food Network</ref> In the Shetland Islands (UK) it is used in the curing of mutton to make [[reestit mutton]], a local delicacy.<ref>{{Cite book |url=https://books.google.com/books?id=CeF0AQAAQBAJ&q=reestit+mutton |title=A Year In A Scots Kitchen |last=Brown |first=Catherine |date=2011-11-14 |publisher=Neil Wilson Publishing Ltd |isbn=9781906476847 |language=en}}</ref> When used as a food additive in the European Union,<ref>UK Food Standards Agency: {{cite web |url=http://www.food.gov.uk/safereating/chemsafe/additivesbranch/enumberlist |title=Current EU approved additives and their E Numbers |access-date=2011-10-27 |url-status=live |archive-url=https://web.archive.org/web/20101007124435/http://www.food.gov.uk/safereating/chemsafe/additivesbranch/enumberlist |archive-date=2010-10-07}}</ref> the compound is referred to as [[E number|E252]]; it is also approved for use as a food additive in the United States<ref>US Food and Drug Administration: {{cite web |url=https://www.fda.gov/Food/FoodIngredientsPackaging/FoodAdditives/ucm191033.htm#ftnT |title=Listing of Food Additives Status Part II |website=[[Food and Drug Administration]] |access-date=2011-10-27 |url-status=live |archive-url=https://web.archive.org/web/20111108002304/https://www.fda.gov/Food/FoodIngredientsPackaging/FoodAdditives/ucm191033.htm#ftnT |archive-date=2011-11-08}}</ref> and Australia and New Zealand<ref>Australia New Zealand Food Standards Code {{cite web |url=http://www.comlaw.gov.au/Details/F2011C00827 |title=Standard 1.2.4 – Labelling of ingredients |date=8 September 2011 |access-date=2011-10-27}}</ref> (where it is listed under its [[List of food additives, Codex Alimentarius|INS number]] 252).<ref name=b1/>

====Possible cancer risk====
Since October 2015, [[World Health Organization|WHO]] classifies processed meat as Group 1 carcinogen (based on epidemiological studies, convincingly [[Carcinogenesis|carcinogenic]] to humans).<ref>{{Cite web |title=Cancer: Carcinogenicity of the consumption of red meat and processed meat |url=https://www.who.int/news-room/questions-and-answers/item/cancer-carcinogenicity-of-the-consumption-of-red-meat-and-processed-meat |access-date=2023-12-29 |website=www.who.int |language=en}}</ref>

In April 2023 the French Court of Appeals of Limoges confirmed that food-watch NGO Yuka was legally legitimate in describing Potassium Nitrate [[E number#E200–E299|E249 to E252]] as a "cancer risk", and thus rejected an appeal by the French {{lang|fr|[[charcuterie]]}} industry against the organisation.<ref>{{cite news |title=Nitrites et jambons "cancérogènes" : nouvelle victoire en appel de Yuka contre un industriel de la charcuterie |trans-title=Nitrites and "carcinogenic" hams: Yuka's new appeal victory against a charcuterie manufacturer |work=Marianne |first=Thomas |last=Rabino |date=13 April 2023 |language=fr |quote=Et ce, en dépit de la multiplicité des avis scientifiques, comme celui du Centre international de recherche sur le cancer, classant ces mêmes additifs, connus sous le nom de E249, E250, E251, E252, parmi les « cancérogènes probables », auxquels la Ligue contre le cancer attribue près de 4 000 cancers colorectaux par an. |trans-quote=And this, despite the multiplicity of scientific opinions, such as that of the International Agency for Research on Cancer, classifying these same additives, known as E249, E250, E251, E252, among the "probable carcinogens", to which the League Against Cancer attributes nearly 4,000 colorectal cancers per year.}}</ref>

===Fertilizer===
Potassium nitrate is used in [[fertilizer]]s as a source of nitrogen and potassium – two of the [[Plant nutrition|macronutrients]] for plants. When used by itself, it has an [[NPK rating]] of 13-0-44.<ref>[http://fieldcrop.msu.edu/uploads/documents/e0896.pdf Michigan State University Extension Bulletin E-896: N-P-K Fertilizers] {{webarchive|url=https://web.archive.org/web/20151224052500/http://fieldcrop.msu.edu/uploads/documents/e0896.pdf |date=2015-12-24}}</ref><ref>{{cite book|title=Environmental Impact of Fertilizer on Soil and Water|date=2004|page=40|url=https://books.google.com/books?id=v_PwAAAAMAAJ|isbn=9780841238114|last1=Hall|first1=William L|last2=Robarge|first2=Wayne P|last3=Meeting|first3=American Chemical Society|publisher=American Chemical Society |url-status=live|archive-url=https://web.archive.org/web/20180127195831/https://books.google.com/books?id=v_PwAAAAMAAJ|archive-date=2018-01-27}}</ref>

===Pharmacology===
* Used in some [[toothpaste]]s for [[Dentine hypersensitivity|sensitive teeth]].<ref>{{cite web|title=Sensodyne Toothpaste for Sensitive Teeth |date=2008-08-03 |url=http://us.sensodyne.com/products_freshmint.aspx |access-date=2008-08-03 |url-status=dead |archive-url=https://web.archive.org/web/20070807010449/http://us.sensodyne.com/products_freshmint.aspx |archive-date=August 7, 2007}}</ref> It has been used since 1980, although the efficacy is not strongly supported by the literature.<ref>{{cite journal|pmid=16803826|url=http://www.ufpi.br/subsiteFiles/ppgo/arquivos/files/Orchardson_&_Gillam_2006_Manejo_da_Hipersensibilidade_Dentinaria.pdf|year=2006|author1=R. Orchardson|author2=D. G. Gillam|name-list-style=amp|title=Managing dentin hypersensitivity|volume=137|issue=7|pages=990–8; quiz 1028–9|journal=Journal of the American Dental Association|doi=10.14219/jada.archive.2006.0321|url-status=dead|archive-url=https://web.archive.org/web/20130729082456/http://www.ufpi.br/subsiteFiles/ppgo/arquivos/files/Orchardson_%26_Gillam_2006_Manejo_da_Hipersensibilidade_Dentinaria.pdf|archive-date=2013-07-29|quote=The efficacy of potassium nitrate to reduce DH, however, is not supported strongly by the literature}}</ref><ref>{{cite journal|url=http://sciencelinks.jp/j-east/article/200315/000020031503A0361500.php|title=The Effect of Potassium Nitrate and Silica Dentifrice in the Surface of Dentin|journal=Japanese Journal of Conservative Dentistry|volume=46|issue=2|pages=240–247|year=2003|author=Enomoto, K|display-authors=etal|url-status=dead|archive-url=https://web.archive.org/web/20100111220400/http://sciencelinks.jp/j-east/article/200315/000020031503A0361500.php|archive-date=2010-01-11}}</ref>
* Used historically to treat asthma.<ref>{{cite book|title=Asthma, presenting an exposition of the nonpassive expiration theory|author=Orville Harry Brown|year=1917|publisher=C.V. Mosby company|page=[https://archive.org/details/asthmapresenting00brow/page/277 277]|url=https://archive.org/details/asthmapresenting00brow}}</ref> Used in some toothpastes to relieve asthma symptoms.<ref>{{cite news|author=Joe Graedon|title='Sensitive' toothpaste may help asthma|url=http://www.chicagotribune.com/health/sc-health-0512-pharm-20100512-11,0,4146905.story|access-date=June 18, 2012|newspaper=The Chicago Tribune|date=May 15, 2010|url-status=dead|archive-url=https://web.archive.org/web/20110916071338/http://www.chicagotribune.com/health/sc-health-0512-pharm-20100512-11,0,4146905.story|archive-date=September 16, 2011}}</ref>
* Used in Thailand as main ingredient in kidney tablets to relieve the symptoms of [[cystitis]], [[pyelitis]] and [[urethritis]].<ref>{{cite web|url=http://www2.fda.moph.go.th/exporters/select/eng/drug/dgexp111e.asp?dgnmt=%C2%D2%E0%C1%E7%B4+%E2%AB%E2%C3%A4%D4%B4%B9%D5%E8&lcnsid=1162&lcnscd=2506&lctnmcd=2392&lctdtnmcd=&lctcd=10280266&lcntype=%BC%C21+&lcnno=5000002&rctype=2A%20&rcno=5000163&dgnmoth=ZORO+KIDNEY+TABLETS&dgtype=2&ndrug=2&typecd=1|title=Local manufactured drug registration for human (combine) – Zoro kidney tablets|website=fda.moph.go.th|location=Thailand|quote=Potassium nitrate 60mg|url-status=dead|archive-date=August 8, 2014|archive-url=https://web.archive.org/web/20140808045035/http://www2.fda.moph.go.th/exporters/select/eng/drug/dgexp111e.asp?dgnmt=%C2%D2%E0%C1%E7%B4+%E2%AB%E2%C3%A4%D4%B4%B9%D5%E8&lcnsid=1162&lcnscd=2506&lctnmcd=2392&lctdtnmcd=&lctcd=10280266&lcntype=%BC%C21+&lcnno=5000002&rctype=2A%20&rcno=5000163&dgnmoth=ZORO+KIDNEY+TABLETS&dgtype=2&ndrug=2&typecd=1}}</ref>
* Combats high blood pressure and was once used as a [[hypotensive]].<ref>{{cite journal|title=On the physiological action of potassium nitrite|author=Reichert ET.|journal=Am. J. Med. Sci.|year=1880|volume=80|pages=158–180|doi=10.1097/00000441-188007000-00011}}</ref>

===Other uses===
* Used as an [[electrolyte]] in a [[salt bridge]].
* Active ingredient of [[condensed aerosol fire suppression]] systems. When burned with the [[free radical]]s of a fire's flame, it produces [[potassium carbonate]].<ref>{{cite web|url=https://www.nist.gov/el/fire_research/upload/R0000245.pdf|title=The evaluation of non-pyrotechnically generated aerosols as fire suppressants|author1=Adam Chattaway|author2=Robert G. Dunster|author3=Ralf Gall|author4=David J. Spring|publisher=United States National Institute of Standards and Technology ([[National Institute of Standards and Technology|NIST]])|url-status=live|archive-url=https://web.archive.org/web/20130729080813/http://www.nist.gov/el/fire_research/upload/R0000245.pdf|archive-date=2013-07-29}}</ref>
* Works as an aluminium cleaner.
* Component (usually about 98%) of some [[tree stump]] removal products. It accelerates the natural [[decomposition]] of the stump by supplying nitrogen for the [[fungi]] attacking the [[wood]] of the stump.<ref>{{cite web |url=http://www.aces.edu/homegarden/news/archives/003560.php|archive-url=https://web.archive.org/web/20120323054236/http://www.aces.edu/homegarden/news/archives/003560.php
| publisher =[[Alabama Cooperative Extension System]]|author=Stan Roark|title=Stump Removal for Homeowners|archive-date=March 23, 2012|date=February 27, 2008}}</ref>
* In [[heat treatment]] of metals as a medium temperature molten salt bath, usually in combination with sodium nitrite. A similar bath is used to produce a durable blue/black finish typically seen on firearms. Its [[oxidizing]] quality, water solubility, and low cost make it an ideal short-term [[rust inhibitor]].<ref>{{cite web|url=http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=/netahtml/PTO/search-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN/6228283|title=Aqueous corrosion inhibitor Note. This patent cites potassium nitrate as a minor constituent in a complex mix. Since rust is an oxidation product, this statement requires justification.|publisher=United States Patent|id=6,228,283|author1=David E. Turcotte|author2=Frances E. Lockwood|date=May 8, 2001|url-status=live|archive-url=https://web.archive.org/web/20180127195832/http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F6228283|archive-date=January 27, 2018}}</ref>
* In [[Chemically strengthened glass|glass toughening]]: molten potassium nitrate bath is used to increase glass strength and scratch-resistance.<ref>{{Cite web |title=Chemical Toughening of Customer Owned Glass - TILSE Yacht Glazing |url=https://www.tilse.com/chemical-toughening/#:~:text=The%20glass%20is%20submerged%20in,+)%20from%20the%20salt%20bath. |access-date=2025-01-17 |website=TILSE GmbH |language=en}}</ref>
* To induce flowering of [[mango]] trees in the Philippines.<ref>{{cite web|url=http://www.wipo.int/wipo_magazine/en/2008/03/article_0001.html|title=The Scientist, the Patent and the Mangoes – Tripling the Mango Yield in the Philippines|publisher=United Nations World Intellectual Property Organization ([[World Intellectual Property Organization|WIPO]])|work=WIPO Magazine|author=Elizabeth March| date=June 2008|archive-date=25 August 2012|archive-url=https://web.archive.org/web/20120825204717/http://www.wipo.int/wipo_magazine/en/2008/03/article_0001.html| url-status =live}}</ref><ref>{{cite web|url=http://beta.searca.org/searca/index.php/news/723-filipino-scientist-garners-2011-dioscoro-l-umali-award|title=Filipino scientist garners 2011 Dioscoro L. Umali Award
| publisher =Southeast Asian Regional Center for Graduate Study and Research in Agriculture ([[Southeast Asian Regional Center for Graduate Study and Research in Agriculture|SEARCA]])
| archive-url =https://web.archive.org/web/20111130182054/http://beta.searca.org/searca/index.php/news/723-filipino-scientist-garners-2011-dioscoro-l-umali-award|archive-date=30 November 2011}}</ref>
* Thermal storage medium in [[power generation]] systems. Sodium and potassium nitrate salts are stored in a molten state with the [[solar energy]] collected by the [[heliostat]]s at the [[Gemasolar Thermosolar Plant]]. [[wikt:ternary|Ternary]] [[Salt (chemistry)|salts]], with the addition of [[calcium nitrate]] or [[lithium nitrate]], have been found to improve the heat storage capacity in the molten salts.<ref>{{cite web|url=http://www.estelasolar.eu/fileadmin/ESTELAdocs/documents/powerplants/Gemasolar/Gemasolar_Torresol.pdf|title=Gemasolar, The First Tower Thermosolar Commercial Plant With Molten Salt Storage System|author1=Juan Ignacio Burgaleta|author2=Santiago Arias|author3=Diego Ramirez|publisher=[[Torresol Energy]]|access-date=7 March 2012|archive-url=https://web.archive.org/web/20120309085029/http://www.estelasolar.eu/fileadmin/ESTELAdocs/documents/powerplants/Gemasolar/Gemasolar_Torresol.pdf|archive-date=9 March 2012|type=Press Release|url-status=dead}}</ref>
* As a source of potassium ions for exchange with sodium ions in [[chemically strengthened glass]].
* As an oxidizer in model rocket fuel called [[Rocket candy]].
* As a constituent in homemade [[smoke bomb]]s.<ref>{{Cite web |title=How to Make the Ultimate Colored Smoke Bomb |url=https://www.thoughtco.com/ultimate-colored-smoke-bomb-605967 |access-date=2023-10-18 |website=ThoughtCo |language=en}}</ref>