Substance profile
Methane
Methane is a colorless gas and is odorless.
01 · Identification
What Methane is
Methane is a colorless gas and is odorless. Its molecular formula is CH4 and its molecular weight is 16.043 g/mol. It boils at -161 °C, melts at -183 °C.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 4th 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 |
|---|---|
| H220 | Extremely flammable gas. |
03 · Physical and chemical properties
Methane 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 | -161.5 °C (-258.7 °F) | HSDB | |
| -161.11 °C (-258 °F) | at 760 mmHg | CAMEO | |
| -161.5 °C (-258.7 °F) | at 760 mmHg | CAMEO | |
| Melting point | -182.57 °C (-296.6 °F) | HSDB | |
| -182.22 °C (-296 °F) | CAMEO | ||
| -182.5 °C (-296.5 °F) | CAMEO | ||
| Density | 0.422 g/cm³ | at -160 °C | CAMEO |
| 0.4228 g/cm³ | at -162 °C | DOE PAC | |
| 0.4325 g/cm³ | range, midpoint shown, at -162 °C | CAMEO | |
| Solubility | Slightly soluble in acetone; soluble in ethanol, ethyl ether, benzene, toluene, methanol | HSDB | |
| 0.91 mL in 1 g ether at 20 °C; 0.60 mL in 1 g ethyl alcohol at 20 °C | at 20 °C | HSDB | |
| In water, 22 mg/L at 25 °C | at 25 °C | HSDB | |
| Vapor pressure | 466000 mmHg | at 25 °C | HSDB |
| 258600 mmHg | at 37.78 °C | CAMEO | |
| 0.0075 mmHg | at -220 °C | HSDB | |
| Flash point | -188 °C (-306.4 °F) | HSDB | |
| -187.78 °C (-306 °F) | CAMEO | ||
| Autoignition temperature | 537.22 °C (999 °F) | HSDB | |
| 540 °C (1004 °F) | CAMEO | ||
| Lower explosive limit (LEL) | 5.3 % by volume | HSDB | |
| 5 % by volume | CAMEO | ||
| Upper explosive limit (UEL) | 14 % by volume | HSDB | |
| 15 % by volume | CAMEO | ||
| Vapor density | 0.55 (air = 1) | CAMEO | |
| 0.6 (air = 1) | ICSC | ||
| 0.554 (air = 1) | at 0 °C | HSDB | |
| Critical temperature and pressure | -82.25 °C (-116 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Methane
Storage conditions
Store in a cool, dry, well-ventilated location. Separate from halogens and oxygen. Outside or detached storage is preferred.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
... Reacts with chlorine and bromine in light (explosively in direct sunlight)
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
Contact of very cold liquefied gas with water may result in vigorous or violent boiling of the product and extremely rapid vaporization due to the large temperature differences involved. If the water is hot, there is the possibility that a liquid "superheat" explosion may occur. Pressures may build to dangerous levels if liquid gas contacts water in a closed container [Handling Chemicals Safely 1980].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Methane in the storage compatibility matrix →