Oxygen Mask

Every time we fly, we hear flight attendants sharing some variation of the oxygen mask rule: “Should the cabin lose pressure, oxygen masks will drop from the overhead area. Please place the mask over your own mouth and nose before assisting others.”

When you are flying you are at a much higher altitude than normal. The air is thinner, which means there is less oxygen. On board every plane is a sophisticated pressure system that ensures everyone can breathe normally, but if something happens where there is a sudden loss in pressure, the effect could be dangerous.

So, in order to keep everyone maintained with enough oxygen, the masks fall down and provide a personal flow.

However, the aircraft only has enough oxygen to provide a flow for “several minutes,” which is a lot shorter time than most believed. The masks are only meant to keep passengers supplied with oxygen until a pilot is able to bring the aircraft down.

Up in the cockpit pilots get their own oxygen masks. Once they’re outfitted, they maneuver the plane to less than 10,000 feet in altitude, where passengers will be able to breathe more easily.

Airplanes don’t carry oxygen tanks above every single seat—that would be far too heavy. Instead, the panel above each seat includes a mixture of all sorts of chemicals that, when burned, create oxygen. (Some passengers report smelling burning when the oxygen masks fall. Don’t worry: It’s not the plane, it’s the creation of oxygen.)

Generally nasal cannulas are the preferred intake method of oxygen to the body. Their slimline shape allows you to move about and perform normal duties with little hindrance.

A nasal cannula allows the delivery of oxygen concentrations of between 24 to 40% at flow rates between 1 to 6 L/min – making them suitable for use with most portable oxygen concentrator units.

An oxygen mask can be used if you find cannulas uncomfortable but will be better suited to a stationary situation such as sitting or in bed.

A simple oxygen mask fits over the nose and mouth with open side ports to allow air to enter and dilute the oxygen as well as allow the escape of carbon dioxide.

An oxygen mask allows oxygen delivery via either the nose or mouth so is suitable for nose and or mouth breathers.

Apart from the physical differences of each device, the primary difference is that oxygen masks allow higher concentrations and rates of flow of oxygen. A simple oxygen mask can deliver oxygen concentrations from 35 to 55% at flow rates between 5 to 10 L/min.