Substance profile
Phosmet
Phosmet is an off-white crystalline solid with an offensive odor.
01 · Identification
What Phosmet is
Phosmet is an off-white crystalline solid with an offensive odor. Its molecular formula is C11H12NO4PS2 and its molecular weight is 317.3 g/mol. It melts at 71.7 °C.
Under the GHS it carries the signal word Danger.
Other names for Phosmet
- phosmet (ISO)
- S-[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl] O,O-di-methyl phosphorodithioate
- O,O-dimethyl-S-phthalimido-methyl phosphorodithioate
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 |
|---|---|
| H361f | Suspected of damaging fertility. |
| H301 | Toxic if swallowed. |
| H332 | Harmful if inhaled. |
| H370 | Causes damage to organs <or state all organs affected, if known> <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: P260, P270, P271, P273, P301, P304, P308, P310, P311, P312, P330, P391, P501
03 · Physical and chemical properties
Phosmet 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 | Decomposes below boiling point (EPA, 1998) | decomposes | CAMEO |
| Melting point | 71.67 °C (161 °F) | CAMEO | |
| 72 °C (161.6 °F) | ICSC | ||
| 71.9 °C (161.4 °F) | DOE PAC | ||
| Density | 1.03 g/cm³ | ICSC | |
| 1.03 g/cm³ | at 20 °C | HSDB | |
| Solubility | 100 G/KG IN DICHLOROMETHANE, 4-METHYLPENT-3-EN-2-ONE, BUTANONE | HSDB | |
| In water, 24.4 mg/L at 20 °C | at 20 °C | HSDB | |
| At 25 °C: 25 mg/L water; 650 g/L acetone; 600 g/L benzene; 5 g/L kerosene; 50 g/L methanol; 300 g/L toluene, methyl isobutyl ketone; 250 g/L xylene. | at 25 °C | HSDB | |
| Vapor pressure | 4.9e-7 mmHg | HSDB | |
| 0.00054 mmHg | at 25 °C | DOE PAC | |
| 0.001 mmHg | at 50 °C | CAMEO | |
| Lower explosive limit (LEL) | Containers may explode in the heat of fire. | HSDB | |
| Corrosivity | SLIGHTLY CORROSIVE TO METALS | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Phosmet
Storage conditions
Store in tightly closed containers in a cool, well vented area away form other pesticide, alkaline conditions, water and other forms of moisture. Where possible, automatically transfer material from drums or other storage containers to process containers. Sources of ignition such as smoking and open flames are prohibited where this chemical is handled, used, or stored. Metal containers involving the transfer of this chemical should be grounded and bonded. Whenever this chemical is used, handled, manufactured, or stored, use explosion-proof electrical equipment and fittings.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Not compatible with other pesticides under alkaline conditions. Contact with water, steam or moisture forms phthalic acids. Slightly corrosive to metals in the presence of moisture.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
Organophosphates, such as PHOSMET, 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. Storage above 113 F, may lead to decomposition. [EPA, 1998].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Phosmet in the storage compatibility matrix →