The newest and best gas used to propel paintballs, very expensive when compared to CO2 but much less volital.
High pressure compressed air (3000 to 5000 psi) is usually used instead of CO2 in tournament paintball. The use of HPA requires specialized high-pressure tanks and regulators, which lower the output pressure to what the markers can handle. HPA tanks can store nitrogen or compressed air--the performance of both is identical. HPA tanks can be constructed of aluminium or steel for 3000psi tanks, or a small aluminium or steel canister surrounded and bonded to carbon fibre for extra strength to store 4500 or 5000psi while reducing weight.
Compressed Air High-pressure compressed air (3000 to 4500 psi) is usually used instead of CO2 in tournament paintball. The use of HPA requires specialized high pressure tanks and regulators, which lower the output pressure to what paintball guns need.