Sodium nitrite
407615
224614593
2008-07-09T17:43:23Z
Rifleman 82
1255637
Reverted edits by [[Special:Contributions/130.218.238.84|130.218.238.84]] ([[User talk:130.218.238.84|talk]]) to last version by 12.216.30.181
{{Chembox new
| Name = Sodium nitrite
| ImageFile = Sodium nitrite.jpg
| ImageSize = 200px
| ImageName = Sodium nitrite
| Section1 = {{Chembox Identifiers
| CASNo = 7632-00-0
}}
| Section2 = {{Chembox Properties
| Formula = NaNO<sub>2</sub>
| MolarMass = 69.00 g/mol
| Appearance = White solid.
| Density = 2.2 g/cm<sup>3</sup>, solid
| Solubility = 82 g/100 ml (20 °C)
| MeltingPt = 270°C
| BoilingPt = 320°C ''decomp.''
}}
| Section3 = {{Chembox Structure
| Coordination =
| CrystalStruct = [[rhombohedral|Trigonal]]
}}
| Section7 = {{Chembox Hazards
| ExternalMSDS = [http://ptcl.chem.ox.ac.uk/MSDS/SO/sodium_nitrite.html External MSDS]
| EUClass = Oxidant ('''O''')<br />,Toxic ('''T'''),<br />Dangerous for<br />the environment ('''N''')
| RPhrases = {{R8}}, {{R25}}, {{R36}}, {{R37}}, {{R38}}, {{R50}}
| SPhrases = {{S26}}, {{S36}}, {{S45}}, {{S61}}
| FlashPt = Non-flammable.
}}
| Section8 = {{Chembox Related
| OtherAnions = [[Sodium nitrate]]
| OtherCations = [[Potassium nitrite]]<br />[[Ammonium nitrite]]
}}
}}
'''Sodium nitrite''', with [[chemical formula]] [[Sodium|Na]][[Nitrogen|N]][[Oxygen|O]]<sub>2</sub>, is used as a [[color fixative]] and [[preservative]] in meats and fish.
When pure, it is a white to slight yellowish crystalline powder. It is very soluble in [[water]] and is [[hygroscopic]]. It is also slowly oxidized by oxygen in the air to [[sodium nitrate]], NaNO<sub>3</sub>. The compound is a strong reducing agent.
It is also used in manufacturing [[azo compound|diazo]] [[dye]]s, [[nitroso compound]]s, and other organic compounds; in dyeing and printing textile fabrics and bleaching fibers; in [[photography]]; as a laboratory [[reagent]] and a [[corrosion inhibitor]]; in metal coatings for phosphatizing and detinning; and in the manufacture of [[rubber]] chemicals. Sodium nitrite also has been used in human and veterinary medicine as a [[vasodilator]], a [[bronchodilator]], and an [[antidote]] for [[cyanide]] poisoning.
==Uses==
===Food additive===
As a [[food additive]], it serves a dual purpose in the [[food]] [[industry]] since it both alters the [[color]] of preserved [[fish]] and [[meat]]s and also prevents growth of ''[[Clostridium botulinum]]'', the [[bacterium|bacteria]] which causes [[botulism]]. In the European Union it may be used only as a mixture with salt containing at most 0.6% sodium nitrite. It has the [[E number]] E250. [[Potassium nitrite]] (E249) is used in the same way.
While this chemical will prevent the growth of bacteria, it can be toxic for mammals. ([[LD]]<sub>50</sub> in rats is 180 mg/kg.) For this reason, sodium nitrite sold as a food additive is dyed bright pink to avoid mistaking it for something else. Cooks and makers of charcuterie often simply refer to sodium nitrite as "pink salt".
Various dangers of using this as a food additive have been suggested and researched by scientists. A principal concern is the formation of [[carcinogenic]] N-[[nitrosamine]]s by the reaction of sodium nitrite with amino acids in the presence of heat in an acidic environment. Sodium nitrite has also been linked to triggering migraines. http://www.fda.gov/FDAC/features/1998/398_pain.html {{Fact|date=March 2008}}
Recent studies have found a link between high processed meat consumption and colon cancer, possibly due to preservatives such as sodium nitrite.
<ref>[http://www3.interscience.wiley.com/cgi-bin/abstract/113337490/ABSTRACT?CRETRY=1&SRETRY=0 publication from wiley]</ref><ref>{{cite journal | author = A. W. Susanna C. Larsson | title = Meat consumption and risk of colorectal cancer: A meta-analysis of prospective studies | year = 2006 | journal = [[International Journal of Cancer]] | volume = 119 | issue = 11 | pages = 2657–2664 | doi = 10.1002/ijc.22170}}</ref>
Recent studies have also found a link between frequent ingestion of meats cured with nitrites and the [[COPD]] form of [[lung disease]].<ref>{{cite news | url = http://www.webmd.com/news/20070417/study-copd-cured-meats-may-be-linked | title = Study: Cured Meats, COPD May Be Linked | author = Miranda Hitti | publisher = WebMD Medical News | date = 17 April 2007}}</ref>
===Disease treatment===
Recently, sodium nitrite has been found to be an effective means to increase blood flow by dilating [[blood vessel]]s, acting as a [[vasodilator]]. Research is ongoing to investigate its applicability towards treatments for [[sickle cell anemia]], cyanide poisoning, [[myocardial infarction|heart attack]]s, [[brain aneurysm]]s, and [[pulmonary hypertension]] in infants.<ref>{{cite news | url = http://www.usatoday.com/news/health/2005-09-05-hot-dog-drug_x.htm | author = [[Associated Press]] | title = Hot dog preservative could be disease cure | date = 9/5/2005}}</ref><ref>{{cite news | url = http://www.newscientist.com/article.ns?id=dn8643 | title = Food preservative fights cystic fibrosis complication | date = 27 January 2006 | publisher = NewScientist.com | author = Roxanne Khamsi}}</ref>
===Synthetic reagent===
Sodium nitrite is used to convert [[amines]] into diazo compounds. The synthetic utility of such a reaction is to render the amino group labile for [[nucleophilic substitution]], as the N<sub>2</sub> group is a better [[leaving group]].
In the laboratory, sodium nitrite is also used to destroy excess [[sodium azide]].<ref>{{cite web | url = http://www.ehs.neu.edu/hazardous_waste/fact_sheets/sodium_azide/ | work = Hazardous Waste Management | title = Sodium Azide | date = March 2003 | publisher = [[Northeastern University]]}}</ref><ref>{{cite book | title = Prudent practices in the laboratory: handling and disposal of chemicals | year = 1995 | publisher = [[National Academy Press]] | city = Washington, D.C. | isbn = 0309052297 | url = http://books.nap.edu/openbook.php?record_id=4911&page=165}}</ref>
: NaNO<sub>2</sub> + H<sub>2</sub>SO<sub>4</sub> → HNO<sub>2</sub> + NaHSO<sub>4</sub>
: 2 NaN<sub>3</sub> + 2 HNO<sub>2</sub> → 3 N<sub>2</sub> + 2 NO + 2 NaOH
==References==
<references/>
==See also==
* [[Nitrosamine]]
* [[Sodium nitrate]]
==External links==
* [http://www.atsdr.cdc.gov/csem/nitrate/ ATSDR - Case Studies in Environmental Medicine - Nitrate/Nitrite Toxicity] U.S. [[Department of Health and Human Services]] (public domain)
* [http://www.ilo.org/public/english/protection/safework/cis/products/icsc/dtasht/_icsc11/icsc1120.htm International Chemical Safety Card 1120].
* [http://ecb.jrc.it/ European Chemicals Bureau].
* [http://www.uga.edu/nchfp/how/cure_smoke/nitrates_nitrites.html National Center for Home Food Preservation Nitrates and Nitrites].
* [http://ntp-server.niehs.nih.gov/index.cfm?objectid=070B04E4-0E6C-7453-7747FB268B93D146 TR-495: Toxicology and Carcinogenesis Studies of Sodium Nitrite (CAS NO. 7632-00-0) Drinking Water Studies in F344/N Rats and B6C3F<sub>1</sub> Mice].
* [http://www.foxnews.com/story/0,2933,208307,00.html FOX news article concerning carcinogicity and hot dogs]
{{Antidotes}}
[[Category:Sodium compounds]]
[[Category:Inorganic compounds]]
[[Category:Nitrites]]
[[Category:Color fixers]]
[[Category:Curing agents]]
[[Category:Food additives]]
[[Category:Garde manger]]
[[ar:نتريت صوديوم]]
[[bs:Natrijum nitrit]]
[[cs:Dusitan sodný]]
[[de:Natriumnitrit]]
[[fr:Nitrite de sodium]]
[[it:Nitrito di sodio]]
[[he:נתרן חנקיתי]]
[[hu:Nátrium-nitrit]]
[[ja:亜硝酸ナトリウム]]
[[no:Natriumnitritt]]
[[pl:Azotan(III) sodu]]
[[pt:Nitrito de sódio]]
[[ru:Нитрит натрия]]
[[fi:Natriumnitriitti]]
[[zh:亚硝酸钠]]