Is oxygen gas pure or a mixture

Air, nitrogen dioxide, and oxygen are common oxidizing agents. However, if important basic rules are not properly followed when dealing with oxygen, for example, the surrounding atmosphere can become enriched with oxygen. The following information describes the dangers associated with such enrichment and explains simple measures that must be observed for the safe use of oxygen.

Gases that occur naturally in the atmosphere are not toxic. If their concentration changes, however, they do have an impact on living beings and the combustion process (especially in the case of oxygen. An adequate amount of oxygen must always be present in atmospheres that are inhaled by humans.

Oxygen itself is not flammable, but it promotes combustion. In contrast, nitrogen and argon inhibit combustion. Changes in the concentration of these gases are imperceptible to the human sensory organs. If not handled properly, accidents can occur.

In order for these gases to be stored in liquid form, they must be cooled to extremely low temperatures (less than -180 ° C at atmospheric pressure). In this state, they can quickly cause cold burns and make certain materials brittle, which in turn can lead to the failure of structural parts.

  • Fire hazards from oxygen enrichment
    Oxygen reacts with most elements. The triggering, speed, severity and extent of these reactions depend on numerous factors, including:

    • Concentration, temperature and pressure of the reactants

    • Ignition energy and type of ignition

  • Flammability of materials
    If the oxygen concentration in an atmosphere increases, even if only by a few percent, the risk of fire increases many times over. Sparks that would be harmless under normal conditions can start fires in oxygen-enriched atmospheres, and materials that would not normally burn in air, including refractories, can burn violently or even ignite spontaneously.

  • Oils and fats made from hydrocarbons
    Oils and fats have a particularly high hazard potential in connection with pure oxygen, as they can ignite spontaneously and burn with explosive violence. They must never be used as a lubricant for devices or systems for oxygen or oxygen-enriched air (special lubricants compatible with oxygen can be used under certain conditions).

  • Smoke
    Many accidents related to combustion processes are caused by lighting cigarettes in oxygen-enriched atmospheres. The risks of smoking in oxygen-enriched atmospheres or in places where oxygen-enrichment can occur are extremely high. An absolute ban on smoking must apply in all such areas.