Substance profile
Methyl Parathion
Methyl Parathion is crystals with a pungent, garlic-like odor.
01 · Identification
What Methyl Parathion is
Methyl Parathion is crystals with a pungent, garlic-like odor. It boils at 143 °C, melts at 35.8 °C.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 3rd degree.
Other names for Methyl Parathion
- parathion - methyl (ISO)
- O,O-dimethyl O-4-nitrophenyl 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 |
|---|---|
| H226 | Flammable liquid and vapour. |
| H330 | Fatal if inhaled. |
| H300 | Fatal if swallowed. |
| H311 | Toxic in contact with skin. |
| H373 | May cause damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H400 | Very toxic to aquatic life. |
| H410 | Very toxic to aquatic life with long lasting effects. |
Precautionary statements: P210, P233, P241, P242, P260, P270, P271, P273, P280, P301, P302, P304, P310, P314, P330, P352, P391, P403, P501
03 · Physical and chemical properties
Methyl Parathion 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 |
|---|---|---|---|
| Boiling point | 142.78 °C (289 °F) | NIOSH | |
| 154 °C (309.2 °F) | at 1.02008 mmHg (reduced pressure) | HSDB | |
| Melting point | 35.8 °C (96.4 °F) | HSDB | |
| 37.22 °C (99 °F) | NIOSH | ||
| Density | 1.36 g/cm³ | NIOSH | |
| 1.358 g/cm³ | at 20 °C | HSDB | |
| Solubility | Soluble in organic solvents | HSDB | |
| In water, 37.7 mg/L at 20 °C | at 20 °C | HSDB | |
| Vapor pressure | 0.00001 mmHg | NIOSH | |
| 0.0000097 mmHg | at 20 °C | CAMEO | |
| 0.0000035 mmHg | at 25 °C | HSDB | |
| Flash point | 42 °C (107.6 °F) | Closed cup | HSDB |
| commercial product, containing xylene, has flashpoint of 115F (EPA, 1998) | CAMEO | ||
| Autoignition temperature | 120 °C (248 °F) | Methyl parathion 80% in xylene | HSDB |
| Lower explosive limit (LEL) | Combustible Solid | NIOSH | |
| Vapor density | 9.1 (air = 1) | CAMEO | |
| Odor threshold | 0.1328 mg/cu m odor low and high. | HSDB | |
| 1.23X10-2 ppm (detection in water; purity not specified) | HSDB | ||
| Odor Threshold Low: 0.0012 [mg/m3] | Haz-Map |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Source notes
Further notes on Methyl Parathion
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
Solubility
Readily soluble in common organic solvents, e.g. dichloromethane, toluene >200, hexane 10 to 20 (all in g/L at 20 °C). Sparingly soluble in petroleum ether and some types of mineral oil.
Source: HSDB
05 · Handling and storage
Storing and handling Methyl Parathion
Storage conditions
Keep container tightly closed in a dry and well-ventilated place.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Strong oxidizers, water [Note: Explosive risk when heated above 122 degrees F].
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
METHYL PARATHION is half decomposed in 8 days at 40 °C. When a sample was heated in a small test tube it decomposed in a few minutes and the residue exploded (Food Chem. 4(1):42. 1956).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Methyl Parathion in the storage compatibility matrix →