The system that circulates the air in the cabin works automatically and will have been devised by the aircraft’s manufacturer in full compliance with all the requirements of the relevant supervisory authorities.
Because of its lower pressure, the air on board will contain less oxygen than air at sea level. For healthy individuals, this does not pose any problem.
All the air inside the cabin is exchanged every two to three minutes. By comparison, the air in an air-conditioned building is only exchanged every five to ten minutes.
In today’s advanced aircraft, all the air circulating in the cabin is passed through highly effective filters that remove over 99% of all the particles in it such as viruses and bacteria.
Research carried out by the World Health Organization (WHO) has found no evidence to date that infectious diseases are passed on more easily aboard an aircraft because of its cabin air circulation system.
Although cabin air is dry, this will not cause people to suffer from dehydration and does not pose any other health risk. Dry eyes and skin can be avoided by using eye drops and moisturising creams.