Acetylsalicylic acid
A member of the class of benzoic acids that is salicylic acid in which the hydrogen that is attached to the phenolic hydroxy group has been replaced by an acetoxy group. A non-steroidal anti-inflammatory drug with cyclooxygenase inhibitor activity. — 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 | 50-78-2 | ChEBI ↗ |
| Molecular formula | C9H8O4 | ChEBI ↗ |
| Molar mass | 180.159 g/mol | ChEBI ↗ |
| Monoisotopic mass | 180.04226 Da | ChEBI ↗ |
| Formal charge | 0 | ChEBI ↗ |
| ChEBI identifier | CHEBI:15365 | ChEBI ↗ |
Cross-source molecular data
PubChem| Molar mass | 180.16 g/mol | PubChem ↗ |
| Exact mass | 180.04225873 Da | PubChem ↗ |
| Computed XLogP | 1.2 | PubChem ↗ |
| Topological polar surface area (Ų) | 63.6 | PubChem ↗ |
| H-bond donors | 1 | PubChem ↗ |
| H-bond acceptors | 4 | PubChem ↗ |
| Rotatable bonds | 3 | 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 identifieracetylsalicylic acid2-(acetyloxy)benzoic acidBSYNRYMUTXBXSQ-UHFFFAOYSA-NCC(=O)Oc1ccccc1C(=O)OInChI=1S/C9H8O4/c1-6(10)13-8-5-3-2-4-7(8)9(11)12/h2-5H,1H3,(H,11,12)Names & 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 governmentAspirin · R06-C-002-JNIOSH, MOE
| Endpoint | Reported classification |
|---|---|
| Respiratory sensitization | Category 1 |
| Hazardous to the aquatic environment （Long-term） | Category 3 |
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 180.159 g/mol from ChEBI. Assumes the substance described by this record; no purity or concentration correction is applied.
Elemental composition
Theoretical mass fractionsCOHCalculated 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.