Substance profile
Hexachlorocyclopentadiene
Hexachlorocyclopentadiene is a dense, oily liquid with a pungent, unpleasant odor.
01 · Identification
What Hexachlorocyclopentadiene is
Hexachlorocyclopentadiene is a dense, oily liquid with a pungent, unpleasant odor. Its molecular formula is C5Cl6 and its molecular weight is 272.8 g/mol. It boils at 239 °C, melts at -9 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
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. |
| H311 | Toxic in contact with skin. |
| H302 | Harmful if swallowed. |
| H314 | Causes severe skin burns and eye damage. |
| H400 | Very toxic to aquatic life. |
| H410 | Very toxic to aquatic life with long lasting effects. |
Precautionary statements: P260, P270, P271, P273, P280, P301, P302, P304, P310, P312, P330, P331, P352, P391, P501
03 · Physical and chemical properties
Hexachlorocyclopentadiene 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 | 239 °C (462.2 °F) | HSDB | |
| 238.89 °C (462 °F) | NIOSH | ||
| 238.89 °C (462 °F) | at 753 mmHg | CAMEO | |
| Melting point | -9 °C (15.8 °F) | HSDB | |
| -8.89 °C (16 °F) | NIOSH | ||
| Density | 1.71 g/cm³ | NIOSH | |
| 1.7019 g/cm³ | at 25 °C | HSDB | |
| Solubility | Soluble in all proportions in acetone, carbon tetrachloride, methanol and hexane. | HSDB | |
| In water, 1.8 mg/L at 25 °C | at 25 °C | HSDB | |
| (77 °F): 0.0002% (Reacts) | at 25 °C | NIOSH | |
| Vapor pressure | 0.06 mmHg | at 25 °C, Extrapolated | HSDB |
| 0.08 mmHg | at 25 °C | NIOSH | |
| Flash point | Non-flammable (EPA, 1998) | CAMEO | |
| Lower explosive limit (LEL) | In presence of moisture explosive hydrogen gas may collect in enclosed space. | HSDB | |
| Noncombustible Liquid | NIOSH | ||
| Vapor density | 9.4 (air = 1) | HSDB | |
| Odor threshold | 0.15 ppm or 1.7 mg/cu m | HSDB | |
| Odor low: 1.5 mg/cu m; Odor high: 3.3 mg/cu m | HSDB | ||
| Odor Threshold Low: 0.15 [ppm] | Haz-Map | ||
| Corrosivity | In presence of moisture, will corrode iron & other metals. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Hexachlorocyclopentadiene
Incompatible materials
Reacts slowly with water to form hydrochloric acid.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
HEXACHLOROCYCLOPENTADIENE is incompatible with strong oxidizing and reducing agents. Also incompatible with many amines, nitrides, azo/diazo compounds, alkali metals (sodium), and epoxides.
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Hexachlorocyclopentadiene in the storage compatibility matrix →