Substance profile
Chlorpyrifos-methyl
Chlorpyrifos-methyl is white crystals with a slight mercaptan odor.
01 · Identification
What Chlorpyrifos-methyl is
Chlorpyrifos-methyl is white crystals with a slight mercaptan odor. Its molecular formula is C7H7Cl3NO3PS and its molecular weight is 322.5 g/mol. It melts at 46 °C.
Under the GHS it carries the signal word Warning.
Other names for Chlorpyrifos-methyl
- chlorpyrifos-methyl (ISO),
- O, O-dimethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate
02 · GHS classification
Hazards and label elements
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
| Code | Hazard statement |
|---|---|
| H317 | May cause an allergic skin reaction. |
| H400 | Very toxic to aquatic life. |
| H410 | Very toxic to aquatic life with long lasting effects. |
Precautionary statements: P261, P272, P273, P280, P313, P333, P391, P501
03 · Physical and chemical properties
Chlorpyrifos-methyl properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 46 °C (114.8 °F) | range, midpoint shown | HSDB |
| Density | 1.64 g/cm³ | at 23 °C | HSDB |
| Solubility | In water, 4.76 mg/L at 20 °C | at 20 °C | HSDB |
| In acetone > 400; methanol 190; hexane 120 (all in g/kg at 20 °C) | at 20 °C | HSDB | |
| In water, 4.0 mg/L at 25 °C | at 25 °C | HSDB | |
| Vapor pressure | 22500 mmHg | at 25 °C | HSDB |
| 0.0000422 mmHg | Haz-Map | ||
| Flash point | 182 °C (359.6 °F) | Cleveland open cup | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Chlorpyrifos-methyl
Storage conditions
Do not contaminate water, food or feed by storage ... Store in a cool, dry location. Do not store in direct sunlight. Do not use or store near heat or open flame. /Storcide II Grain, Bin and Warehouse Insecticide/
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Incompatible with alkaline & strongly acidic materials.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
A chlorinated organophosphate derivative. Organophosphates are susceptible to formation of highly toxic and flammable phosphine gas in the presence of strong reducing agents such as hydrides. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides. It is incompatible with strong acids and bases.
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Chlorpyrifos-methyl in the storage compatibility matrix →