Hazards of Pressurizing Gases

Nitrogen (N2) and helium (He) are both odorless, colorless gases used for pressurizing rocket-propulsion systems. Helium is chemically inert and nitrogen is chemically inactive. Neither gas is corrosive, explosive, nor combustible.

The only possible hazards arising from the use of either nitrogen or helium stem from (1) high storage and transfer pressures normally employed, or (2) shortage of breathing oxygen because of extremely high concentrations of either gas.