Sodium hydrogensulfite
An inorganic sodium salt having hydrogensulfite as the counterion. — ChEBI
Safety documents & references
2 indexed referencesFind a product-specific SDS
Safety guides and government classification records are not a manufacturer’s SDS. Match supplier, product number, concentration, physical form, region and revision before using a document.
Identity & molecular properties
Source-linked values| CAS number | 7631-90-5 | ChEBI ↗ |
| Molecular formula | HO3S.Na | ChEBI ↗ |
| Molar mass | 104.062 g/mol | ChEBI ↗ |
| Monoisotopic mass | 103.95441 Da | ChEBI ↗ |
| Formal charge | 0 | ChEBI ↗ |
| ChEBI identifier | CHEBI:26709 | ChEBI ↗ |
Cross-source molecular data
PubChem| Molar mass | 104.06 g/mol | PubChem ↗ |
| Exact mass | 103.95440935 Da | PubChem ↗ |
PubChem computed values are shown separately from the ChEBI record. An exact InChIKey match was used to connect the records. Molecular descriptors do not describe a supplied product’s purity, particle size or performance.
Names & structural identifiers
Copy any identifiersodium hydrogensulfitesodium hydrogensulfiteDWAQJAXMDSEUJJ-UHFFFAOYSA-MO=S([O-])O.[Na+]InChI=1S/Na.H2O3S/c;1-4(2)3/h;(H2,1,2,3)/q+1;/p-1Classification & relationships
ChEBI ontologyRoles recorded in ChEBI
Database role annotations describe reported biological or chemical roles; they are not product approvals or recommendations for use.
Safety classification · Japan
NITE / Japanese governmentSodium hydrogen sulfite (34% aqueous solution) · 25B0042
| Endpoint | Reported classification |
|---|---|
| Serious eye damage/eye irritation | Category 2B |
| Specific target organ toxicity - Single exposure | Category 3 （Respiratory tract irritation） |
Selected source-reported endpoints. Other endpoints, rationales and conditions remain in the original classification. Missing or unlisted information does not mean non-hazardous. This is not a global classification or transport decision.
Read the original NITE classificationMass ↔ amount of substance
Calculated from sourced massUses 104.062 g/mol from ChEBI. Assumes the substance described by this record; no purity or concentration correction is applied.
Elemental composition
Theoretical mass fractionsOSNaHCalculated theoretical mass fractions from the reported formula and PubChem periodic-table atomic masses. These are not assay or purity results.
Research & patent references
Selected source associationsSources & record history
Checked 27 Sep 2026Release 255, 9 September 2026. ChEBI three-star (manually annotated) source entry. View original record ↗ · CC BY 4.0
PubCAS formats source data, connects references and computes explicitly labelled conversions. CAS cross-references are supplied by ChEBI; they do not constitute CAS verification or endorsement.