Is oxygen a flammable gas?
Oxygen is classified as a strongly energetic oxidizing gas and by itself is not flammable. A flammable gas is one that will act as a fuel that will burn in the presence of oxygen. Thus oxygen is not a flammable gas but is an oxidizer. In the presence of oxygen concentrations above atmospheric pressure and concentrations, materials that readily burn in atmospheric conditions will burn more vigorously and may spontaneously combust; and, materials that normally do not burn in atmospheric conditions may burn in the presence of oxygen concentrations above atmospheric pressure and concentrations.