Where does the oxygen for the oxygen mask really come from?

Oxygen masks on the aircraft will be dropped automatically if the cabin suddenly loses air pressure and helps passengers breathe in a few minutes.

But do you know where these masks get oxygen from? Will commercial aircraft carry both a giant oxygen chamber just for backup in such emergencies? ScienceABC will help you answer these questions.

Short answer: Commercial airplanes have a chemical oxygen generation system , in which the release of oxygen masks activates the needle, triggering a chemical reaction and producing oxygen.

Oxygen mask on the plane.

The need to have an emergency oxygen system on board

Air pressure will decrease as elevation increases. Through a certain height on the surface of the earth, the air becomes too thin and cannot breathe. In most commercial aircraft, if the pressure in the cabin is disturbed at an altitude of over 14,000 feet (about 4.2 km), the control panel containing oxygen masks will automatically open and fall to the seat. of passengers. Typically, aircraft design experts will add a spare mask to each row of seats, so the 3-seater row seats will have 4 oxygen masks.

Note that these passenger masks do not need to wear the entire time until the aircraft lands. They only provide oxygen for a short time, and that time is enough for pilots to lower their altitude into a safe area where outside air can breathe.

Of course, the crew will also announce "remove the mask" so people know that they have reached the safe area of ​​the atmosphere and no need for oxygen masks.

So where do oxygen masks get oxygen?

Most of us think that aircraft carrying a giant oxygen tank on board and oxygen masks will be connected there. In the case of a pressure regulator in the cabin, the tank can turn on to provide oxygen to the crew and passengers. Similarly, this tank will turn off when the plane has reached a safe height. In this way, the aircraft can conserve unused oxygen.

It sounds reasonable but that is not what happens in practice because oxygen is not stored in tank tanks; instead, oxygen is produced by chemical reactions.

Aircraft containing oxygen systems are often referred to as popular "oxygen lamps" , which contain some chemicals that will release oxygen as a byproduct. The chemicals contained in the oxygen lamp include sodium chloride (NaClO-3), barium peroxide (BaO-2) less than 5% and potassium perchlorate (KClO-4) less than 1%.

This mixture will be triggered by the temperature through a small explosion by tugging on the mask. This process will release the metal fire and cause a chemical reaction. Chemicals burn and release oxygen as a by-product and transfer to the nose through a pipe after filtering out other by-products.

Because the actual chemicals are "burned" in the reaction, it is possible that the passenger senses a burning smell and can cause panic. However, this is completely normal and safe for aircraft.

The reactions take place until the chemical runs out. Therefore, a mask can provide enough oxygen to breathe within 12-20 minutes, depending on the type and size of the oxygen generator. At any rate, you only need the oxygen mask until the plane drops to a height of 10,000 feet (about 3km).

So if you go on a plane and experience a loss of pressure, you don't need to be scared, just pull on the oxygen mask, put it on your nose and enjoy pure oxygen.