Chlorpyrifos
An organic thiophosphate that is O,O-diethyl hydrogen phosphorothioate in which the hydrogen of the hydroxy group has been replaced by a 3,5,6-trichloropyridin-2-yl group. — 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 | 2921-88-2 | ChEBI ↗ |
| Molecular formula | C9H11Cl3NO3PS | ChEBI ↗ |
| Molar mass | 350.591 g/mol | ChEBI ↗ |
| Monoisotopic mass | 348.92628 Da | ChEBI ↗ |
| Formal charge | 0 | ChEBI ↗ |
| ChEBI identifier | CHEBI:34631 | ChEBI ↗ |
Cross-source molecular data
PubChem| Molar mass | 350.6 g/mol | PubChem ↗ |
| Exact mass | 348.926284 Da | PubChem ↗ |
| Computed XLogP | 5.3 | PubChem ↗ |
| Topological polar surface area (Ų) | 72.7 | PubChem ↗ |
| H-bond donors | 0 | PubChem ↗ |
| H-bond acceptors | 5 | PubChem ↗ |
| Rotatable bonds | 6 | 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 identifierchlorpyrifosO,O-diethyl O-(3,5,6-trichloropyridin-2-yl) phosphorothioateSBPBAQFWLVIOKP-UHFFFAOYSA-NCCOP(=S)(OCC)Oc1nc(Cl)c(Cl)cc1ClInChI=1S/C9H11Cl3NO3PS/c1-3-14-17(18,15-4-2)16-9-7(11)5-6(10)8(12)13-9/h5H,3-4H2,1-2H3Names & 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 governmentO,O-diethyl O-(3,5,6-trichloro-2-pyridyl) thiophosphate [Chlorpyrifos] · H29-B-020
| Endpoint | Reported classification |
|---|---|
| Acute toxicity （Oral） | Category 3 |
| Serious eye damage/eye irritation | Category 2B |
| Specific target organ toxicity - Single exposure | Category 1 (nervous system) |
| Specific target organ toxicity - Repeated exposure | Category 1 (nervous system, adrenal gland), Category 2 (eye, haemal system, liver) |
| Hazardous to the aquatic environment （Acute） | Category 1 |
| Hazardous to the aquatic environment （Long-term） | Category 1 |
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 350.591 g/mol from ChEBI. Assumes the substance described by this record; no purity or concentration correction is applied.
Elemental composition
Theoretical mass fractionsCClOSPNHCalculated 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.