... pakage or packed according to demand Name: helium gasPurity: 99.9~99.999%Property: colourless, odourless, non-flammable, non-reactive, ... balloons are perhaps the most well-known use of helium, they are a minor part of all helium use. Another minor use is in rocketry, where ... ≤5,CH4 ≤10,H2 O≤30 GB/T 7445-1995 99.999% O2 +Ar≤1,N2 ≤5,CO≤1,CO2 ... 1,CH4 ≤1,H2 O≤3 GB/T 7445-1995 99.9999% O2 +Ar≤0.2,N2 ≤0.4,CO ...