Liquefied petroleum gas or liquid petroleum gas (LPG or LP gas), also referred to as simply propane or butane, are flammable mixtures of hydrocarbon gases used as fuel in heating appliances, cooking equipment, and vehicles.

Most people know propane as the fuel in the white container attached to a barbecue grill. But propane has long proven its versatility for heating homes and water, cooking, drying clothes, fueling gas fireplaces and as an alternative fuel for vehicles. However, more propane is used to make petrochemicals- which are the building blocks for plastics, alcohols, fibers and cosmetics, to name a few.

Butane is a colorless gas with a faint petroleum-like odor. For transportation it may be stenched. It is shipped as a liquefied gas under its vapor pressure. Contact with the liquid can cause frostbite. It is easily ignited. Its vapors are heavier than air. Any leak can be either liquid or vapor. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket. It is used as a fuel, an aerosol propellant, in cigarette lighters, and to make other chemicals.