Except oxygen gas, all other gases have the risk of suffocation. Therefore, asphyxiant accidents are rare, so the asphyxiant hazard of gas is often ignored. Although some gases have no special toxicity, their danger is only that at high concentrations, the partial pressure of oxygen in the air inhaled by people will be reduced, resulting in hypoxia and asphyxia.

  Liquefied gas is the most dangerous of these gases, because when they leak, they will rapidly vaporize and cause local anoxic atmosphere.

  Recommended reading: oxidation of bottled gas