Beryllium oxide
A beryllium molecular entity consisting of beryllium (+2 oxidation state) and oxide in the ratio 1:1. In the solid state, BeO adopts the hexagonal wurtzite structure form while in the vapour phase, it is present as discrete diatomic covalent molecules. — ChEBI
Safety documents & references
1 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 | 1304-56-9 | ChEBI ↗ |
| Molecular formula | BeO | ChEBI ↗ |
| Molar mass | 25.011 g/mol | ChEBI ↗ |
| Monoisotopic mass | 25.0071 Da | ChEBI ↗ |
| Formal charge | 0 | ChEBI ↗ |
| ChEBI identifier | CHEBI:62842 | ChEBI ↗ |
Cross-source molecular data
PubChem| Molar mass | 25.012 g/mol | PubChem ↗ |
| Exact mass | 25.0070977 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 identifierberyllium oxideoxoberylliumLTPBRCUWZOMYOC-UHFFFAOYSA-N[Be]=[O]InChI=1S/Be.ONames & synonyms
Names are supplied by ChEBI. Trade names and related synonyms may describe a broader product context.
Classification & 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 governmentBeryllium oxide · 485
| Endpoint | Reported classification |
|---|---|
| Skin corrosion/irritation | Category 2 |
| Serious eye damage/eye irritation | Category 2A |
| Carcinogenicity | Category 1A |
| Reproductive toxicity | Category 2 |
| Specific target organ toxicity - Single exposure | Category 1 (respiratory system) |
| Specific target organ toxicity - Repeated exposure | Category 1 (respiratory system, blood system) |
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 25.011 g/mol from ChEBI. Assumes the substance described by this record; no purity or concentration correction is applied.
Elemental composition
Theoretical mass fractionsOBeCalculated 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.