An oxygen mask ( engl. oxygen mask ) is a device that the face or nose and mouth covered and reduced under conditions of atmospheric pressure or in a contaminated environment enables you to breathe pure oxygen or a breathing gas mixture. This type of mask is usually used by a container with the help of a tube, at the end of a mask body is attached to supply the oxygen or breathing mixture of the lungs. The oxygen mask may be made of plastic, silicone or rubber. We distinguish different types of producers in addition to full and half masks. The latter enclose the human nose and mouth, while full face masks also cover the eye area.
Oxygen masks are worn by pilots, among other things, have their aircraft do not have a pressurized cabin and operate at altitudes where by the low oxygen partial pressure sufficient oxygenation of the organism is no longer present. Even in military aircraft with a pressurized cabin crews may wear oxygen masks in order to remain operational in the event of an accident with possibly more necessary activation of the ejection seat or under combat conditions.
For passenger aircraft to plastic oxygen masks are located in the cabin ceiling above each seat and on the toilet. When loss of pressure in the aircraft cabin opens a flap in the ceiling and the oxygen masks fall from the cabin ceiling. The masks are connected through a tube to the ceiling and in general any form separately by a chemical gas generator ( SC ) is supplied with oxygen. For large aircraft such as the A380 a central supply oxygen bottles is preferred for reasons of weight.
Even when extreme altitude mountaineering find oxygen masks application, mostly for ascents of mountains with an altitude of over 7,000 meters, in order to avoid the consequences of prolonged hypoxia due to the thin air at high altitude mountain.