Isoniazide
A carbohydrazide obtained by formal condensation between pyridine-4-carboxylic acid and hydrazine. — 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 | 54-85-3 | ChEBI ↗ |
| Molecular formula | C6H7N3O | ChEBI ↗ |
| Molar mass | 137.142 g/mol | ChEBI ↗ |
| Monoisotopic mass | 137.05891 Da | ChEBI ↗ |
| Formal charge | 0 | ChEBI ↗ |
| ChEBI identifier | CHEBI:6030 | ChEBI ↗ |
Cross-source molecular data
PubChem| Molar mass | 137.14 g/mol | PubChem ↗ |
| Exact mass | 137.058911855 Da | PubChem ↗ |
| Computed XLogP | -0.7 | PubChem ↗ |
| Topological polar surface area (Ų) | 68 | PubChem ↗ |
| H-bond donors | 2 | PubChem ↗ |
| H-bond acceptors | 3 | PubChem ↗ |
| Rotatable bonds | 1 | 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 identifierisoniazidepyridine-4-carbohydrazideQRXWMOHMRWLFEY-UHFFFAOYSA-NNNC(=O)c1ccncc1InChI=1S/C6H7N3O/c7-9-6(10)5-1-3-8-4-2-5/h1-4H,7H2,(H,9,10)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 governmentIsoniazid · 23A5063
| Endpoint | Reported classification |
|---|---|
| Acute toxicity （Oral） | Category 4 |
| Reproductive toxicity | Category 2 |
| Specific target organ toxicity - Single exposure | Category 1 (nervous system) |
| Specific target organ toxicity - Repeated exposure | Category 1 (nervous system, liver, blood) |
| Hazardous to the aquatic environment （Acute） | Category 3 |
| 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 137.142 g/mol from ChEBI. Assumes the substance described by this record; no purity or concentration correction is applied.
Elemental composition
Theoretical mass fractionsCNOHCalculated 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.