Here is a danger safety sign found by my geological engineer/exploration geologist daughter Évelyne.
The air in Earth's atmosphere is made up of approximately 78 % dinitrogen (N2) and 21 % dioxygen (O2). N2 gas can prove catastrophic and fatal if inhaled in large quantity because body will be left oxygen-deprived. Depending on the dose of N2 gas inhaled, it can lead to full body paralysis to instant death.
