UN1956 COMPRESSED GAS, N.O.S. (CARBON DIOXIDE, METHANE) 2.2 1.0% METHANE, 0.1% ETHANE, 0.01% PROPANE, 0.1% ISOBUTANE, 0.1% HYDROGEN SULFIDE, 10 PPM METHYL MERCAPTAN, 5 PPM ETHYL MERCAPTAN, 7 PPM CARBONYL SULFIDE, CARBON DIOXIDE BALANCE CERTIFIED, SIZE 150AL