An MPS gas is a mixture of two or more of propane, butane, butadiene, methylacetylene (propyne, CHC≡CH) and propadiene (CH=C=CH). They are marketed under different names including: "MPS", "Chem-O-Lean", "Apachi Gas", "FG-2 Gas", "Flamex" and "natural gas". The most commonly known type of MPS gas is the discontinued MAPP gas.
As a fuel gas, it burns hotter than propylene, propane or natural gas.