The truth about plane cabin air
Many travellers believe that cabin air will make you sick. So what’s the truth?
What air is inside the cabin?
Commercial airplanes fly at such high altitudes that people would not be able to survive in the low pressure environment outside – that also means you can’t just crack and window to get some fresh air. A plane’s cabin is airtight and compressed air is drawn from the engines, treated and released into the cabin as breathable air. Between 10% and 50% of this air is recirculated through the cabin during the flight, mixed with the fresh air drawn from the engines.
How is the air treated?
Once the compressed air leaves the engines, it passes through an air conditioner to be cooled and then through a high tech HEPA (High Efficiency Particulate Air) filter. This filter removes almost all airborne particulates, bacteria and viruses. Aircraft manufacturers state that the filters remove between 94% and 99% of all impurities in the air.
Is it safe?
In a word, yes. One US doctor is quoted as saying that the air onboard a plane is cleaner than what you would breathe in a day care centre. There’s a complete changeover of the air in the cabin every two to three minutes, which is a much higher rate than you would find in another crowded place like an office or cinema. Plane air is also much cleaner than onboard other forms of transport, regardless of open windows.
Can pilots influence air quality?
There’s a bit of an air travel urban legend that says pilots can slow down the air recirculation process or reduce the amount of fresh air that’s pulled in, all as a way to save fuel and lower costs. You’ll be happy to know that is completely false. Pilots don’t have such high level control over airflow and have no way to upset the ratios. On some aircraft they can adjust airflow, but only to ensure that the cabin is comfortable and safe for passengers.