Gas
| Property | Specification |
| State | Gaseous |
| Density | 0.6 – 0.9 kg/m³ |
| Viscosity | < 0.1 cP (near zero) |
| API Gravity | N/A |
| Flash Point | -160°C (for Liquefied Natural Gas - LNG) |
| Boiling Point | -161.5°C |
| Calorific Value | 33,000 – 40,000 kJ/m³ |
| Color | Colorless |
| Odor | Odorless (unless odorized for safety) |
| Composition |
Primarily methane (CH₄), with small amounts of ethane, propane, butane, carbon dioxide, and nitrogen |
| Sulfur Content | Trace or low (0.1% – 2%) |
| Carbon Content | 75% – 95% methane |
| Vapor Pressure | High (varies with temperature) |