Bottled gas is a liquefied petroleum gas that is shipped and stored in portable steel cylinders or tanks for use as a fuel. The standard commercial bottled gases are propane, butane, and mixtures of propane and butane. The gas is kept liquefied under pressure in a steel cylinder for safe, efficient, and convenient transportation and storage. When released from the pressure container, it changes from a liquid to a gaseous state.
Bottled gas provides die fuel for heating and cooking and for hot water in mobile trailer homes and in homes in rural areas; campers use bottled gas for heating and lighting and for cooking in camp stoves. Repairmen use a small cylindrical bottle of propane as a torch for jobs such as removing paint or soldering, and bottled gas also is used as a fuel for internal-combustion engines, for example in trucks and farm tractors.
Propane and butane, which are obtained by separation from petroleum or natural gas, are non-toxic, colorless, and odorless. For safety, an odor-nt is added in the cylinder to warn when a leak develops.