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Record Information
Creation Date2009-06-22 16:08:41 UTC
Update Date2014-12-24 20:24:43 UTC
Accession NumberT3D1839
Common NameSodium selenite
ClassSmall Molecule
DescriptionSodium selenite is a chemical compound of sodium and selenium. It is the most common water-soluble form of selenium. Together with the related barium and zinc salts, sodium selenite is mainly used in the manufacture of colorless glass. Its pink coloration cancels out the green color imparted by iron impurities. Selenium is a nonmetal element with the atomic number 34 and the chemical symbol Se. Selenium rarely occurs in its elemental state in nature and is usually found in sulfide ores such as pyrite, partially replacing the sulfur in the ore matrix. It may also be found in silver, copper, lead, and nickel minerals. Though selenium salts are toxic in large amounts, trace amounts of the element are necessary for cellular function in most animals, forming the active center of the enzymes glutathione peroxidase, thioredoxin reductase, and three known deiodinase enzymes. (4, 5)
Compound Type
  • Industrial/Workplace Toxin
  • Inorganic Compound
  • Pollutant
  • Selenium Compound
  • Synthetic Compound
Chemical Structure
Disodium selenite
Disodium selenium trioxide
Selenious acid (H2seo3), disodium salt
Selenious acid, disodium salt
Sodium selenite pentahydrate
Sodium selenite, anhydr
Chemical FormulaNa2O3Se
Average Molecular Mass172.940 g/mol
Monoisotopic Mass173.881 g/mol
CAS Registry Number10102-18-8
IUPAC Namedisodium selenite
Traditional Namedisodium selenite
InChI IdentifierInChI=1S/2Na.H2O3Se/c;;1-4(2)3/h;;(H2,1,2,3)/q2*+1;/p-2
Chemical Taxonomy
Description belongs to the class of inorganic compounds known as alkali metal selenites. These are inorganic compounds in which the largest oxoanion is selenite, and in which the heaviest atom not in an oxoanion is an alkali metal.
KingdomInorganic compounds
Super ClassMixed metal/non-metal compounds
ClassAlkali metal oxoanionic compounds
Sub ClassAlkali metal selenites
Direct ParentAlkali metal selenites
Alternative Parents
  • Alkali metal selenite
  • Inorganic sodium salt
  • Inorganic oxide
  • Inorganic salt
Molecular FrameworkNot Available
External Descriptors
Biological Properties
StatusDetected and Not Quantified
Cellular Locations
  • Cytoplasm
  • Extracellular
Biofluid LocationsNot Available
Tissue LocationsNot Available
PathwaysNot Available
ApplicationsNot Available
Biological RolesNot Available
Chemical RolesNot Available
Physical Properties
AppearanceWhite crystals.
Experimental Properties
Melting PointNot Available
Boiling PointNot Available
SolubilityNot Available
LogPNot Available
Predicted Properties
pKa (Strongest Acidic)11.93ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area63.19 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity17.44 m³·mol⁻¹ChemAxon
Polarizability5.32 ųChemAxon
Number of Rings0ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectrum TypeDescriptionSplash KeyView
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-00di-0900000000-57d63483e7bf17a35250JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-00di-0900000000-89eda8dae9a313d62146JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-00di-3900000000-a3a84418c0d31d3301fdJSpectraViewer
Toxicity Profile
Route of ExposureOral (3) ; inhalation (3) ; dermal (3)
Mechanism of ToxicitySelenium readily substitutes for sulfur in biomolecules and in many biochemical reactions, especially when the concentration of selenium is high and the concentration of sulfur is low. Inactivation of the sulfhydryl enzymes necessary for oxidative reactions in cellular respiration, through effects on mitochondrial and microsomal electron transport, might contribute to acute selenium toxicity. Selenomethionine (a common organic selenium compound) also appears to randomly substitute for methionine in protein synthesis. This substitution may affect the structure and functionability of the protein, for example, by altering disulfide bridges. Inorganic forms of selenium appear to react with tissue thiols by redox catalysis, resulting in formation of reactive oxygen species and causing damage by oxidative stress. (3)
MetabolismSelenium may be absorbed through inhalation and ingestion, while some selenium compounds may also be absorbed dermally. Once in the body, selenium is distributed mainly to the liver and kidney. Selenium is an essential micronutrient and is a component of glutathione peroxidase, iodothyronine 5'-deiodinases, and thioredoxin reductase. Organic selenium is first metabolized into inorganic selenium. Inorganic selenium is reduced stepwise to the intermediate hydrogen selenide, which is either incorporated into selenoproteins after being transformed to selenophosphate and selenocysteinyl tRNA or excreted into the urine after being transformed into methylated metabolites of selenide. Elemental selenium is also methylated before excretion. Selenium is primarily eliminated in the urine and feces, but certain selenium compounds may also be exhaled. (3)
Toxicity ValuesLD50: 7 mg/kg (Oral, Rat) (6) LD50: 3 mg/kg (Intravenous, Rat) (6)
Lethal DoseNot Available
Carcinogenicity (IARC Classification)3, not classifiable as to its carcinogenicity to humans. (2)
Uses/SourcesSodium selenite is mainly used in the manufacture of colorless glass. Its pink coloration cancels out the green color imparted by iron impurities. (5)
Minimum Risk LevelChronic Oral: 0.005 mg/kg/day (1)
Health EffectsChronic oral exposure to high concentrations of selenium compounds can produce a disease called selenosis. The major signs of selenosis are hair loss, nail brittleness, and neurological abnormalities (such as numbness and other odd sensations in the extremities). Animal studies have shown that selenium may also affect sperm production and the female reproductive cycle. (3)
SymptomsShort-term oral exposure to high concentrations of selenium may cause nausea, vomiting, and diarrhea. Brief exposures to high levels of elemental selenium or selenium dioxide in air can result in respiratory tract irritation, bronchitis, difficulty breathing, and stomach pains. Longer-term exposure to either of these air-borne forms can cause respiratory irritation, bronchial spasms, and coughing. (3)
TreatmentEYES: irrigate opened eyes for several minutes under running water. INGESTION: do not induce vomiting. Rinse mouth with water (never give anything by mouth to an unconscious person). Seek immediate medical advice. SKIN: should be treated immediately by rinsing the affected parts in cold running water for at least 15 minutes, followed by thorough washing with soap and water. If necessary, the person should shower and change contaminated clothing and shoes, and then must seek medical attention. INHALATION: supply fresh air. If required provide artificial respiration.
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
DrugBank IDNot Available
HMDB IDNot Available
PubChem Compound ID24934
ChemSpider ID23308
UniProt IDNot Available
ChEBI ID48843
BioCyc IDNot Available
CTD IDD018038
Stitch IDSodium selenite
PDB IDNot Available
ACToR ID7524
Wikipedia LinkNot Available
Synthesis ReferenceNot Available
General References
  1. ATSDR - Agency for Toxic Substances and Disease Registry (2001). Minimal Risk Levels (MRLs) for Hazardous Substances. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). [Link]
  2. International Agency for Research on Cancer (2014). IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. [Link]
  3. ATSDR - Agency for Toxic Substances and Disease Registry (2003). Toxicological profile for selenium. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). [Link]
  4. Wikipedia. Selenium. Last Updated 7 June 2009. [Link]
  5. Wikipedia. Sodium selenite. Last Updated 25 May 2009. [Link]
  6. The Physical and Theoretical Chemistry Laboratory of Oxford University (2005). Material Safety Data Sheet (MSDS) for sodium selenite. [Link]
Gene Regulation
Up-Regulated Genes
GeneGene SymbolGene IDInteractionChromosomeDetails
Down-Regulated Genes
GeneGene SymbolGene IDInteractionChromosomeDetails