The air onboard the latest generation of commercial aircraft is exceptionally clean. It consists of around 60% of fresh air from outside. The air circulating in the cabin is cleaned by High Efficiency Particulate Air filters (HEPA) which remove most impurities such as dust, bacteria, and viruses. Air quality onboard matches the standards for clinical operating theatres. Moreover, air flow circulates vertically, from top to bottom, ensuring additional safety.
A good tip: Turn on the small overhead air jet to enjoy a freshly filtered airstream.