Substance profile
Cyclopentane
Cyclopentane is a colorless liquid with a mild, sweet odor.
01 · Identification
What Cyclopentane is
Cyclopentane is a colorless liquid with a mild, sweet odor. Its molecular formula is C5H10 and its molecular weight is 70.13 g/mol. It boils at 49.2 °C, melts at -93.4 °C.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 3rd degree.
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 |
|---|---|
| H225 | Highly flammable liquid and vapour. |
| H412 | Harmful to aquatic life with long lasting effects. |
Precautionary statements: P210, P233, P241, P242, P273, P403, P501
03 · Physical and chemical properties
Cyclopentane 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 | 49.2 °C (120.6 °F) | HSDB | |
| 49.44 °C (121 °F) | NIOSH | ||
| 49.28 °C (120.7 °F) | at 760 mmHg | CAMEO | |
| Melting point | -93.4 °C (-136.1 °F) | HSDB | |
| -93.89 °C (-137 °F) | NIOSH | ||
| Density | 0.75 g/cm³ | NIOSH | |
| 0.7457 g/cm³ | at 20 °C | HSDB | |
| 0.74 g/cm³ | at 20 °C | CAMEO | |
| Solubility | Miscible with other hydrocarbon solvents, alcohol, ether | HSDB | |
| Miscible with ethanol, ethyl ether, acetone, benzene, petroleum ether, carbon tetrachloride | HSDB | ||
| In water, 156 ppm at 25 °C | at 25 °C | HSDB | |
| Vapor pressure | 337.528 mmHg | at 20 °C | ICSC |
| 317.8 mmHg | at 25 °C | HSDB | |
| Flash point | -20 °C (-4 °F) | HSDB | |
| -37.22 °C (-35 °F) | NIOSH | ||
| -37 °C (-34.6 °F) | ICSC | ||
| Autoignition temperature | 361.11 °C (682 °F) | HSDB | |
| 320 °C (608 °F) | ICSC | ||
| Lower explosive limit (LEL) | 1.1 % by volume | NIOSH | |
| 1.1 % by volume | approx. | CAMEO | |
| Upper explosive limit (UEL) | 8.7 % by volume | HSDB | |
| 8.7 % by volume | approx. | CAMEO | |
| Vapor density | 2.42 (air = 1) | HSDB | |
| 2.4 (air = 1) | ICSC |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Cyclopentane
Storage conditions
Conditions for safe storage, including any incompatibilities: 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.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Strong oxidizers (e.g. chlorine, bromine, fluorine).
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
CYCLOPENTANE is incompatible with strong oxidizing agents such as chlorine, bromine, fluorine. (NIOSH, 2024).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Cyclopentane in the storage compatibility matrix →