Substance profile
Thionyl Chloride
Thionyl Chloride is a colorless to pale yellow or reddish liquid with a suffocating odor.
01 · Identification
What Thionyl Chloride is
Thionyl Chloride is a colorless to pale yellow or reddish liquid with a suffocating odor. Its molecular formula is Cl2OS and its molecular weight is 118.97 g/mol. It boils at 76 °C, melts at -104 °C.
Under the GHS it carries the signal word Danger. It is classed as corrosives.
Other names for Thionyl Chloride
- thionyl dichloride
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 |
|---|---|
| H332 | Harmful if inhaled. |
| H302 | Harmful if swallowed. |
| H314 | Causes severe skin burns and eye damage. |
Supplemental EU statements: EUH014, EUH029
Precautionary statements: P260, P270, P271, P280, P301, P304, P310, P312, P330, P331
03 · Physical and chemical properties
Thionyl Chloride 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 °C (168.8 °F) | at 760 mmHg | HSDB |
| 76.11 °C (169 °F) | NIOSH | ||
| 76.11 °C (169 °F) | at 760 mmHg | CAMEO | |
| Melting point | -104.5 °C (-156.1 °F) | HSDB | |
| -104.44 °C (-156 °F) | NIOSH | ||
| Density | 1.64 g/cm³ | NIOSH | |
| Solubility | Decomp in acids, alc, alkalies; in cold and hot water | HSDB | |
| Miscible with benzene, chloroform, carbon tetrachloride | HSDB | ||
| Decomposes (fumes) in water | decomposes | HSDB | |
| Vapor pressure | 100 mmHg | at 21.11 °C | NIOSH |
| 110 mmHg | at 26 °C | HSDB | |
| Lower explosive limit (LEL) | Noncombustible Liquid | NIOSH | |
| Vapor density | 4.1 (air = 1) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Thionyl Chloride
Storage conditions
Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Keep away from water. Never allow product to get in contact with water during storage. Handle and store under inert gas. Storage class (TRGS 510): 6.1D: Non-combustible, acute toxic Cat.3 / toxic hazardous materials or hazardous materials causing chronic effects.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Incompatible materials: Alcohols, amines, metals, reacts violently with water.
Source: Hazardous Substances Data Bank (HSDB)
Planning storage for a mix of chemicals? Check Thionyl Chloride in the storage compatibility matrix →