Substance profile
Phosphorus trichloride
Phosphorus trichloride is clear colorless, fuming liquid with a pungent odor.
01 · Identification
What Phosphorus trichloride is
Phosphorus trichloride is clear colorless, fuming liquid with a pungent odor. Its molecular formula is Cl3P and its molecular weight is 137.33 g/mol. It boils at 76.1 °C, melts at -93.6 °C, is soluble in water.
Under the GHS it carries the signal word Danger. It is classed as corrosives.
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 |
|---|---|
| H330 | Fatal if inhaled. |
| H300 | Fatal if swallowed. |
| 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>. |
| H314 | Causes severe skin burns and eye damage. |
Supplemental EU statements: EUH014, EUH029
Precautionary statements: P260, P270, P271, P280, P301, P304, P310, P314, P330, P331
03 · Physical and chemical properties
Phosphorus trichloride 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 | 76.1 °C (169 °F) | HSDB | |
| 76.11 °C (169 °F) | NIOSH | ||
| 76.11 °C (169 °F) | at 760 mmHg | CAMEO | |
| Melting point | -93.6 °C (-136.5 °F) | HSDB | |
| -112.22 °C (-170 °F) | NIOSH | ||
| Density | 1.58 g/cm³ | NIOSH | |
| 1.574 g/cm³ | at 21 °C | HSDB | |
| Solubility | Reacts with water, ethanol; soluble in benzene, chloroform, ether | HSDB | |
| Soluble in carbon tetrachloride | HSDB | ||
| Reacts | NIOSH | ||
| Vapor pressure | 100 mmHg | NIOSH | |
| 100 mmHg | at 21 °C | CAMEO | |
| 120 mmHg | at 25 °C | HSDB | |
| Autoignition temperature | Not flammable (USCG, 1999) | CAMEO | |
| Lower explosive limit (LEL) | Noncombustible Liquid; however, a strong oxidizer that may ignite combustibles upon contact. | NIOSH | |
| Reacts violently with water producing heat and decomposition products including hydrochloric acid and phosphorous acid, causing fire and explosion hazard. | decomposes | HSDB | |
| Vapor density | 4.75 (air = 1) | HSDB | |
| Odor threshold | Phosphorus trichloride ... can be detected at about 0.5 mg/cu m. | HSDB | |
| Critical temperature and pressure | 285.5 °C (545.9 °F) | HSDB | |
| Corrosivity | Corrodes most common construction materials. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Phosphorus trichloride
Storage conditions
Provision to contain effluent from fire extinguishing. Separated from food and feedstuffs. See Chemical Dangers. Dry. Well closed. Ventilation along the floor.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Reacts with water to form hydrochloric acid, which reacts with most metals to form flammable hydrogen gas.
Source: Hazardous Substances Data Bank (HSDB)
Planning storage for a mix of chemicals? Check Phosphorus trichloride in the storage compatibility matrix →