Substance profile
Phosphorus oxychloride
Phosphorus oxychloride is a clear, colorless to yellow, oily liquid with a pungent & musty odor.
01 · Identification
What Phosphorus oxychloride is
Phosphorus oxychloride is a clear, colorless to yellow, oily liquid with a pungent & musty odor. Its molecular formula is Cl3OP and its molecular weight is 153.33 g/mol. It boils at 106 °C, melts at 1.3 °C.
Under the GHS it carries the signal word Danger. It is classed as corrosives.
Other names for Phosphorus oxychloride
- phosphoryl trichloride
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. |
| H302 | Harmful if swallowed. |
| H372 | Causes 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, P312, P314, P330, P331
03 · Physical and chemical properties
Phosphorus oxychloride 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 | 105.8 °C (222.4 °F) | HSDB | |
| 105.56 °C (222 °F) | NIOSH | ||
| 106.11 °C (223 °F) | at 760 mmHg | CAMEO | |
| Melting point | 1.25 °C (34.3 °F) | HSDB | |
| 1.11 °C (34 °F) | NIOSH | ||
| 1.22 °C (34.2 °F) | CAMEO | ||
| Density | 1.645 g/cm³ | ICSC | |
| 1.645 g/cm³ | at 25 °C | HSDB | |
| Solubility | Reacts with water | HSDB | |
| Decomposes | decomposes | NIOSH | |
| Decomposes (NIOSH, 2024) | decomposes | CAMEO | |
| Vapor pressure | 40 mmHg | at 27.22 °C | NIOSH |
| 40 mmHg | at 27.3 °C | HSDB | |
| Flash point | Not Flammable (EPA, 1998) | CAMEO | |
| Autoignition temperature | Not flammable (USCG, 1999) | CAMEO | |
| Lower explosive limit (LEL) | SMALL QUANTITIES OF PHOSPHORUS OXYCHLORIDE WERE EMPTIED INTO SCRAP NICKEL DRUM CONTAINING ABOUT 28 LB OF WATER. AFTER DELAY OF 15-30 MIN, THE DRUM EXPLODED. | HSDB | |
| Vapor density | 5.3 (air = 1) | HSDB | |
| Critical temperature and pressure | 331.8 °C (629.2 °F) | HSDB | |
| Corrosivity | PRODUCTS OF ITS REACTION WITH WATER RAPIDLY CORRODE STEEL & MOST METALS | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Fire and explosion
Fire and explosion behaviour of Phosphorus oxychloride
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.
Fire and explosion
POOR STIRRING DURING FORMYLATION OF 2,5-DIMETHYLPYRROLE WITH THE PREFORMED COMPLEX OF DIMETHYLFORMAMIDE WITH PHOSPHORYL CHLORIDE CAUSED ERUPTION OF FLASK CONTENTS. REACTION OF COMPLEX WITH LOCAL EXCESS OF PYRROLE MAY HAVE BEEN INVOLVED.
Source: HSDB
AN EXPLOSION OCCURRED IMMEDIATELY AFTER POURING & CAPPING OF CHLORIDE RECOVERED FROM PREPN OF FERROCENE-1,1'-DICARBONYL CHLORIDE. THE STORAGE BOTTLE CONTAINED PHOSPHORYL CHLORIDE RECOVERED FROM SIMILAR PREPN & WHICH HAS BEEN STORED FOR ABOUT 3 MO.
Source: HSDB
05 · Handling and storage
Storing and handling Phosphorus oxychloride
Storage conditions
Keep in tightly closed containers.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
WILL REACT WITH WATER OR STEAM TO PRODUCE HEAT AND TOXIC AND CORROSIVE FUMES.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
PHOSPHORUS OXYCHLORIDE is water reactive. Incompatible with strong oxidizing agents, alcohols, bases (including amines). May react vigorously or explosively if mixed with diisopropyl ether or other ethers in the presence of trace amounts of metal salts [J. Haz. Mat., 1981, 4, 291]. Combining the chloride with zinc dust caused immediate ignition, due to the formation of phosphine gas which ignites, [Mellor, 1940, Vol. 8, 1025]. An exotherm starting with the mixing of phosphorus oxychloride with acetone (a ketone) lead to an explosion, may behave similarly with other ketones, [Organic Process Research and Development, Vol.4, No. 6,200, "Phosphorus Oxychloride and Acetone: An Incompatibility Investigation Using ARC."]
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Phosphorus oxychloride in the storage compatibility matrix →