FESS Nasal Defence helps relieve nasal and sinus congestion due to low humidity, dry environments such as on planes or in air-conditioned environments. The solution keeps nasal passages moist and helps wash away bacteria and other pollutants. The air inside aircraft cabin is low in humidity. This can dry the nasal mucous membranes and increase discomfort during the flight. FESS Nasal Defence helps moisturise your nose and help guard against airborne infections.