Nitrous acid (CHEM002539)

IdentificationTaxonomyBiological PropertiesPhysical PropertiesToxicity ProfileSpectraConcentrationsLinksReferencesTargets (9)XML
Record Information
Version1.0
Creation Date2009-08-05 14:20:32 UTC
Update Date2026-04-14 17:38:15 UTC
Accession NumberCHEM002539
Identification
Common NameNitrous acid
ClassSmall Molecule
DescriptionNitrous acid is a weak and monobasic acid known only in solution and in the form of nitrite salts. It is prepared by adding any mineral acid to sodium nitrite and is used in chemical synthesis. Nitrite is a toxic compound known to cause methemoglobinemia. (3, 5)
Contaminant Sources
  • T3DB toxins
Contaminant Type
  • Industrial/Workplace Toxin
  • Inorganic Compound
  • Nitrite
  • Non-Metal
  • Synthetic Compound
Chemical Structure
Thumb
MOLSDFPDBSMILESInChI
Synonyms
ValueSource
[NO(OH)]ChEBI
HNO2ChEBI
Nitrosyl hydroxideChEBI
Acid, nitrousHMDB
Nitrous acidHMDB
Chemical FormulaHNO2
Average Molecular Mass47.013 g/mol
Monoisotopic Mass47.001 g/mol
CAS Registry Number7782-77-6
IUPAC Namenitrous acid
Traditional Namenitrous acid
SMILESON=O
InChI IdentifierInChI=1S/HNO2/c2-1-3/h(H,2,3)
InChI KeyIOVCWXUNBOPUCH-UHFFFAOYSA-N
Chemical Taxonomy
Description belongs to the class of inorganic compounds known as non-metal nitrites. These are inorganic non-metallic compounds containing a nitrite as its largest oxoanion.
KingdomInorganic compounds
Super ClassHomogeneous non-metal compounds
ClassNon-metal oxoanionic compounds
Sub ClassNon-metal nitrites
Direct ParentNon-metal nitrites
Alternative Parents
Substituents
  • Non-metal nitrite
  • Inorganic nitrite
  • Inorganic oxide
Molecular FrameworkNot Available
External Descriptors
Biological Properties
StatusDetected and Not Quantified
OriginExogenous
Cellular Locations
  • Cytoplasm
  • Extracellular
Biofluid LocationsNot Available
Tissue LocationsNot Available
PathwaysNot Available
ApplicationsNot Available
Biological RolesNot Available
Chemical RolesNot Available
Physical Properties
StateLiquid
AppearancePale blue solution.
Experimental Properties
PropertyValue
Melting PointNot Available
Boiling PointNot Available
SolubilityNot Available
Predicted Properties
PropertyValueSource
logP0.17ChemAxon
pKa (Strongest Basic)-3.5ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count1ChemAxon
Polar Surface Area49.66 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity8.72 m³·mol⁻¹ChemAxon
Polarizability2.81 ųChemAxon
Number of Rings0ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Spectra
Spectra
Spectrum TypeDescriptionSplash KeyView
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, PositiveNot AvailableSpectrum
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 10V, Negative (Annotated)splash10-0007-9000000000-9cf82c70d7bc0883ea95Spectrum
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 25V, Negative (Annotated)splash10-0005-9000000000-e52588fd7e5b6989584dSpectrum
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 40V, Negative (Annotated)splash10-0007-9000000000-891acfcb7562d9875939Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-0002-9000000000-701578487c4dc8b94d22Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-0002-9000000000-701578487c4dc8b94d22Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0002-9000000000-701578487c4dc8b94d22Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-0002-9000000000-9c61b79c18a51c772d86Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-0002-9000000000-9c61b79c18a51c772d86Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0002-9000000000-9c61b79c18a51c772d86Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-0002-9000000000-f32ca30bef7a838cd1d9Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-0002-9000000000-f32ca30bef7a838cd1d9Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0002-9000000000-25fa00bd60fa653bf828Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-0002-9000000000-a0441e6336543cb88423Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-0002-9000000000-a0441e6336543cb88423Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0002-9000000000-a0441e6336543cb88423Spectrum
Toxicity Profile
Route of ExposureOral (3) ; inhalation (3)
Mechanism of ToxicityNitrite causes the autocatalytic oxidation of oxyhemoglobin to hydrogen peroxide and methemoglobin. This elevation of methemoglobin levels is a condition known as methemoglobinemia, and is characterized by tissue hypoxia, as methemoglobin cannot bind oxygen. (1, 4)
MetabolismNitrites and their metabolites are excreted in the urine. (3)
Toxicity ValuesNot Available
Lethal Dose10 to 100 mg/kg for an adult human. (6)
Carcinogenicity (IARC Classification)Ingested nitrate or nitrite under conditions that result in endogenous nitrosation is probably carcinogenic to humans (Group 2A). (2)
Uses/SourcesNitrous acid is used in chemical synthesis. (5)
Minimum Risk LevelNot Available
Health EffectsNitrite poisoning causes methemoglobinemia. Nitrites may cause pregnancy complications and developmental effects. They may also be carcinogenic. (3)
SymptomsNitrite poisoning causes methemoglobinemia. Symptoms include cyanosis, cardiac dysrhythmias and circulatory failure, and progressive central nervous system (CNS) effects. CNS effects can range from mild dizziness and lethargy to coma and convulsions. (3)
TreatmentMethemoglobinemia can be treated with supplemental oxygen and methylene blue 1% solution administered intravenously slowly over five minutes followed by IV flush with normal saline. Methylene blue restores the iron in hemoglobin to its normal (reduced) oxygen-carrying state. (4)
Concentrations
Not Available
DrugBank IDNot Available
HMDB IDHMDB0002786
FooDB IDFDB023064
Phenol Explorer IDNot Available
KNApSAcK IDNot Available
BiGG IDNot Available
BioCyc IDNot Available
METLIN IDNot Available
PDB IDNot Available
Wikipedia LinkNitrous acid
Chemspider ID22936
ChEBI ID25567
PubChem Compound ID24529
Kegg Compound IDC00088
YMDB IDYMDB00135
ECMDB IDECMDB02786
References
Synthesis ReferenceNot Available
MSDSNot Available
General References
1. Nakata, Sumio; Eiki, Toshio; Tanaka, Norihiro; Koyama, Tadashi; Tsukui, Hiroto; Watanabe, Shizuo. Production of nitrite ions from trinitrophenyl myosin and from trinitrophenyl subfragment-1. Journal of Biochemistry (Tokyo, Japan) (1986), 99(1), 27-32.
2. Takahama U, Oniki T, Murata H: The presence of 4-hydroxyphenylacetic acid in human saliva and the possibility of its nitration by salivary nitrite in the stomach. FEBS Lett. 2002 May 8;518(1-3):116-8.
3. Miyado T, Tanaka Y, Nagai H, Takeda S, Saito K, Fukushi K, Yoshida Y, Wakida S, Niki E: Simultaneous determination of nitrate and nitrite in biological fluids by capillary electrophoresis and preliminary study on their determination by microchip capillary electrophoresis. J Chromatogr A. 2004 Oct 8;1051(1-2):185-91.
4. Tsikas D: Methods of quantitative analysis of the nitric oxide metabolites nitrite and nitrate in human biological fluids. Free Radic Res. 2005 Aug;39(8):797-815.