It’s pretty safe to assume that just about everyone is familiar with flight attendant safety demonstrations at the start of every flight: “In case there is a loss in cabin pressure, yellow oxygen masks will deploy from the ceiling compartment located above your head…” That’s great, but do you really need to wear those masks if they drop? Or is the oxygen there just to make people “high” and calm them down?
As an airline pilot, I can tell you that yes, you definitely do need to wear the oxygen masks if the airplane cabin becomes depressurized. Also, I can assure you that the oxygen is not there to get you “high” or make you delirious. Unfortunately, several movies have promoted a myth about the purpose of the oxygen masks. Most notably, Brad Pitt’s character in “Fight Club” makes the claim that oxygen “gets you high,” and implies that the masks are simply a way to calm everyone during an emergency. This is completely false. The masks are necessary because without a pressurized cabin, the air is too thin and contains too little oxygen for your body to function normally. If the airplane was to depressurize and you did not put on a mask, you would lose consciousness after a short while. How long it takes to pass out depends on the altitude that the plane is at and how quickly the cabin pressure decreases. It should be noted that pure oxygen does not cause you to become “stoned” or inebriated. On the contrary, it would be a lack of oxygen from a depressurization at altitude that would cause you to feel drunk or “stoned.” The 100% pure oxygen is needed to counteract those effects.
Up at altitude in an airplane, the atmosphere contains less and less oxygen as altitude increases, making the air “thinner.” This means that there is less oxygen for your lungs to process and pass along through the blood stream to the brain and other organs. If the air gets too “thin” the body cannot get enough oxygen to function and your brain and thought processes slow down. If this trend continues, you may eventually pass out. On average, most people don’t start experiencing a degraded ability to think or reason until they are above 15,000 feet. At this altitude you will certainly remain conscious and be able to move, but your brain function will be greatly diminished. For those of us on the ground, this really is not a consideration unless you are planning on climbing Mount Everest.
On the other hand, commercial airliners typically fly at an altitude of anywhere from 30,000 to 40,000 feet. These airplanes are pressurized to keep the cabin at an artificially lower altitude (roughly 6,000 to 8,000 feet) so that people can breathe comfortably. During a loss of cabin pressure, it is likely that the air would be so thin and contain so little oxygen that the average person would pass out in about 15 to 20 seconds without the help of an oxygen mask. This is why the flight attendant safety demonstration directs you to put on your own mask before helping others. If you put the mask on your child or neighbor first, you could potentially pass out before you are able to put on your own mask. It should be noted that each mask also has its own oxygen supply that will last for more than ten minutes. That is more than enough time to allow the pilots to quickly descend to a safe altitude (where the air is thick enough for everyone to breath normally). As an airline pilot who has had to use all of the emergency equipment as part of my training, I can assure you that those oxygen masks do not cause you to “get high” or become euphoric. They are simply there for your safety and enable you to continue to function normally during a loss of cabin pressure. This is an extremely unlikely scenario, but like everything else, airlines always take the most conservative approach when it comes to your safety.
-The truth and myths about oxygen masks on airplanes-