Substance profile
Hexamethylphosphoramide
Hexamethylphosphoramide is colorless, mobile liquid with an aromatic odor.
01 · Identification
What Hexamethylphosphoramide is
Hexamethylphosphoramide is colorless, mobile liquid with an aromatic odor. Its molecular formula is C6H18N3OP and its molecular weight is 179.2 g/mol. It boils at 233 °C, melts at 6.1 °C, is miscible with water.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
Other names for Hexamethylphosphoramide
- hexamethylphosphoric triamide
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 |
|---|---|
| H350 | May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H340 | May cause genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
03 · Physical and chemical properties
Hexamethylphosphoramide 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 | 233 °C (451.4 °F) | at 760 mmHg | HSDB |
| 232.78 °C (451 °F) | NIOSH | ||
| 232.78 °C (451 °F) | at 760 mmHg | CAMEO | |
| Melting point | 6.11 °C (43 °F) | NIOSH | |
| 7.2 °C (45 °F) | ICSC | ||
| Density | 1.03 g/cm³ | NIOSH | |
| 1.03 g/cm³ | at 20 °C | HSDB | |
| 1.024 g/cm³ | at 25 °C | CAMEO | |
| Solubility | MISCIBLE WITH WATER & WITH MOST ORG LIQ; IMMISCIBLE WITH HIGH-BOILING SATURATED HYDROCARBONS | HSDB | |
| Miscible | NIOSH | ||
| Solubility in water: very good | ICSC | ||
| Vapor pressure | 0.03 mmHg | HSDB | |
| 0.07 mmHg | at 25 °C | CAMEO | |
| Flash point | 104.44 °C (220 °F) | NIOSH | |
| 105.56 °C (222 °F) | CAMEO | ||
| 105 °C (221 °F) | ICSC | ||
| Lower explosive limit (LEL) | Class IIIB Combustible Liquid: Fl.P. at or above 200 °F. | NIOSH | |
| Vapor density | 6.18 (air = 1) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Hexamethylphosphoramide
Storage conditions
PRECAUTIONS FOR "CARCINOGENS": Storage site should be as close as practical to lab in which carcinogens are to be used, so that only small quantities required for ... expt need to be carried. Carcinogens should be kept in only one section of cupboard, an explosion-proof refrigerator or freezer (depending on chemicophysical properties ...) that bears appropriate label. An inventory ... should be kept, showing quantity of carcinogen & date it was acquired ... Facilities for dispensing ... should be contiguous to storage area. /Chemical Carcinogens/
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Oxidizers, strong acids, chemically active metals (e.g., potassium, sodium, magnesium, zinc).
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
HEXAMETHYLPHOSPHORAMIDE may react with strong oxidizing agents and strong acids (NTP, 1992). 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.
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Hexamethylphosphoramide in the storage compatibility matrix →