Association Française du Gaz Naturel pour Véhicules

At mild temperatures, methane is a gas less dense than air. It is not very soluble in water. However, methane is combustible. Safe - as only mixtures ranging from 5 to 15% in the air are explosive - methane is not toxic when inhaled.

On the other hand, there is a risk of suffocation if there is an extreme lack of oxygen. In domestic uses, natural gas is odourless: traces of ill-smelling organic sulphur are added (it concerns mercaptan de butyl tertiaire, (CH3)3CSH and sulphide du dimethyl, CH3-S-CH3). This addition is only to be used for detecting natural gas in the household.
The same principal is used in industrial and the utility industries in order to detect any leak.

Not only can methane be naturally extracted from natural gas but also synthesised through distilling bitumen carbon or by heating a mixture of carbon and hydrogen. Equally, it may be produced in the laboratory by heating sodium acetate with sodium hydroxide or even by producing a reaction with aluminium carbonate (Al4C3) and water.