LPG or LP Gas is the abbreviation of Liquefied Petroleum Gas. This group of products includes saturated Hydrocarbons - Propane (C3H8) and Butane (C4H10), which can be stored/transported separately or as a mixture. They exist as gases at normal room temperature and atmospheric pressure.

 Varieties of LPG bought and sold include mixes that are mostly propane (C3H8), mostly butane (C4H10) and, most commonly, mixes including both propane and butane. In the northern hemisphere winter, the mixes contain more propane, while in summer, they contain more butane.In the United States, mainly two grades of LPG are sold: commercial propane and HD-5. These specifications are published by the Gas Processors Association (GPA)[5] and the American Society of Testing and Materials (ASTM).[6] Propane/butane blends are also listed in these specifications.