Sodium nitrite is a chemical compound, sodium ion with inorganic sodium salt and a physiological derivative of nitric oxide to which it can be bioactivated.  It is very soluble in water and liquid ammonia, stable under anaerobic conditions. Slightly soluble in ether, ethanol, methanol and other organic solvents. It reacts with oxygen to form sodium nitrate when exposed to air.

It occurs as a white or yellowish crystalline powder.

What it is used for and where it is used

It is used in medicine, food, fertiliser, fixative in dyes, biological insecticide, antifreeze, raw material in the production of caffeine and saccharin, corrosion inhibitor for steel, bleaching agent for silk and linen, heat treatment agent for metals, bleaching, electroplating.

Chromatography: to determine mercury, potassium and chlorate. Nitrification and diazotization reagent (temporary generation of sodium nitrite and hydrochloric acid). Soil analysis.  Serum bilirubin measured in liver function tests.

Medicine

Sodium nitrite is an analytical reagent, a vasodilator that generates nitric oxide in tissues by involving haemoglobin, an antidote to cyanide poisoning.

It also has antimicrobial activity by inhibiting enzymes or disrupting electron transport in various microbes (1), can improve cardiac function and, as an effective cardioprotective treatment, is also cost-effective.

This study investigated the protective response in the presence of ischaemia or hypoxic conditions and concluded that exogenous sodium nitrite had protective effects against hepatic ischaemia-reperfusion injury (2).

Sickle cell skin ulceration has a negative impact on quality of life. Topical sodium nitrite has been shown to reduce the size of sickle cell leg ulcers. This study examined how topical sodium nitrite affected quality of life scores in patients with sickle cell leg ulcers. Topical sodium nitrite has the potential to improve quality of life, especially in younger people. Longer duration of treatment and randomised trials are needed to confirm the efficacy of this topical therapy (3).

Sodium nitrite can be considered an effective therapeutic agent for diseases of the central nervous system (4).

Sodium nitrite (Medicine) studies

Its use in food is permitted but at concentrations strictly established by European food additive legislation (Regulation (EC) No 1333/2008). It is labelled with the number E250 on the European additives list as a preservative and is subject to an Acceptable Daily Intake (ADI). 

Typical optimal characteristics of the commercial product Sodium nitrite

Appearance	Colorless or yellow crystal
Content of sodium nitrite %	≥98.5
Boiling Point	320 °C
Melting Point	271 °C(lit.)
Density	1.29 g/mL at 25 °C
PSA	52.49000
LogP	0.25060
Water Solubility	820 g/L (20 ºC)
Water insoluble matter	≤0.05%
Sodium nitrate	≤0.8%
Chloride	≤50ppm
Moisture %	≤2.0
Storage	2-8°C
Safety

• Molecular Formula : NNaO₂
• Molecular Weight : 68.995
• Exact Mass   68.982674
• CAS : 7632-00-0
• UNII M0KG633D4F
• EC Number   231-555-9
• DSSTox Substance ID DTXSID0020941
• IUPAC  sodium;nitrite
• InChI=1S/HNO2.Na/c2-1-3;/h(H,2,3);/q;+1/p-1  
• InChl Key      LPXPTNMVRIOKMN-UHFFFAOYSA-M
• SMILES   N(=O)[O-].[Na+]
• MDL number  MFCD00011118
• PubChem Substance ID 329752451
• ChEBI  78870
• ICSC    1120
• NSC   77391
• RTECS   RA1225000
• UN   1500   3287

Synonyms :

• Nitrous acid, sodium salt
• Nitrite, Sodium

References________________________________________________

(1) Mueller-Herbst S, Muehlig A, Kabisch J, Pichner R, Scherer S. The food additives nitrite and nitrate and microbiological safety of food products. American Journal of Clinical Microbiology. 2014;6(1):13. doi: 10.3844/ajmsp.2015.1.3.

(2) Choi EK, Jung H, Kim KJ, Kang SJ, Kim HJ, Lim JA, Kwak KH, Lim DG. Sodium Nitrite Attenuates Hepatic Ischemia-Reperfusion Injury in Rats. Exp Clin Transplant. 2019 Jun;17(3):348-354. doi: 10.6002/ect.2018.0169.

(3) Connor JL Jr, Sclafani JA, Kato GJ, Hsieh MM, Minniti CP. Brief topical sodium nitrite and its impact on the quality of life in patients with sickle leg ulcers. Medicine (Baltimore). 2018 Nov;97(46):e12614. doi: 10.1097/MD.0000000000012614.

(4) Pluta RM, Oldfield EH. Sodium nitrite as a therapeutic agent for central nervous system diseases. Surg Neurol. 2006 Jul;66(1):5-7; discussion 8-10. doi: 10.1016/j.surneu.2005.10.017.

Compendium of the most significant studies with reference to properties, intake, effects.

Wolff A, Günther T, Albert T, Johne R. Effect of Sodium Chloride, Sodium Nitrite and Sodium Nitrate on the Infectivity of Hepatitis E Virus. Food Environ Virol. 2020 Dec;12(4):350-354. doi: 10.1007/s12560-020-09440-2. 

Abstract. Here, an HEV preparation in phosphate-buffered saline (PBS) was subjected to different salt concentrations and the remaining infectivity was measured in a cell culture assay. 

Neto-Neves EM, Pinheiro LC, Nogueira RC, Portella RL, Batista RI, Tanus-Santos JE. Sodium nitrite improves hypertension-induced myocardial dysfunction by mechanisms involving cardiac S-nitrosylation. J Mol Cell Cardiol. 2019 Sep;134:40-50. doi: 10.1016/j.yjmcc.2019.06.012.

Abstract. We investigated whether nitrite improves the cardiac function in normotensive and in hypertensive rats.

Sriboonyong T, Kawamatawong T, Sriwantana T, Srihirun S, Titapiwatanakun V, Vivithanaporn P, Pornsuriyasak P, Sibmooh N, Kamalaporn H. Efficacy and safety of inhaled nebulized sodium nitrite in asthmatic patients. Pulm Pharmacol Ther. 2021 Feb;66:101984. doi: 10.1016/j.pupt.2020.101984.

Abstract. Here, we aimed to investigate the efficacy and safety of inhaled sodium nitrite as add-on therapy with inhaled corticosteroid (ICS) in adult patients with persistent asthma.

Bebarta VS, Brittain M, Chan A, Garrett N, Yoon D, Burney T, Mukai D, Babin M, Pilz RB, Mahon SB, Brenner M, Boss GR. Sodium Nitrite and Sodium Thiosulfate Are Effective Against Acute Cyanide Poisoning When Administered by Intramuscular Injection. Ann Emerg Med. 2017 Jun;69(6):718-725.e4. doi: 10.1016/j.annemergmed.2016.09.034.

Abstract. The 2 antidotes for acute cyanide poisoning in the United States must be administered by intravenous injection. In the out-of-hospital setting, intravenous injection is not practical, particularly for mass casualties, and intramuscular injection would be preferred. The purpose of this study is to determine whether sodium nitrite and sodium thiosulfate are effective cyanide antidotes when administered by intramuscular injection.

Gonçalves-Rizzi VH, Nascimento RA, Possomato-Vieira JS, Dias-Junior CA. Sodium Nitrite Prevents both Reductions in Circulating Nitric Oxide and Hypertension in 7-Day Lead-Treated Rats. Basic Clin Pharmacol Toxicol. 2016 Mar;118(3):225-30. doi: 10.1111/bcpt.12480.

Abstract. we expanded previous reports and evaluated the effects of sodium nitrite in 7-day lead-treated rats.

Hughan KS, Levine A, Helbling N, Anthony S, DeLany JP, Stefanovic-Racic M, Goodpaster BH, Gladwin MT. Effects of Oral Sodium Nitrite on Blood Pressure, Insulin Sensitivity, and Intima-Media Arterial Thickening in Adults With Hypertension and Metabolic Syndrome. Hypertension. 2020 Sep;76(3):866-874. doi: 10.1161/HYPERTENSIONAHA.120.14930.

Abstract. Preclinical studies in rodent models suggest there may be a benefit of nitrite in lowering serum triglyceride levels and improving the metabolic syndrome. In a phase 2 study, we evaluated the safety and efficacy of chronic oral nitrite therapy in patients with hypertension and the metabolic syndrome.