The requirement is part of a new set of infection guidelines for air passengers in Denmark agreed between the aviation trade body Dansk Luftfart, the country's transport and business ministries, and its health and transport agencies.
“We are very pleased that there is now agreement on simple and pragmatic rules that can create a safe journey for passengers”, Michael Svane, director of Dansk Luftfart, said in a statement.
The Danish Health Authority does not currently advise the general public to wear face masks in public, arguing that the benefits are unproven, and that it might encourage people not to follow social distance guidelines.
“People who wear face masks might take the rules less seriously and, for example, go out if they have symptoms, or be less likely to keep their distance,” it warns.
In requiring face masks, Denmark is following the guidelines of the European Aviation Safety Agency.
Svane told Ritzau that the masks meant that “we can avoid having restrictions in cabins”, such as leaving an empty seat between each passenger.
Denmark's Transport Minister Benny Engelbrecht told Ritzau that the new guidelines would make it easier to restart flights in and out of Denmark.
“It can ensure that aviation can get started nice and smoothly,” he said. “Business travellers in particular need to be able to travel, and to the extent that you travel to airports outside Denmark, it is most appropriate to follow the same guidelines.”
Svane estimated that only 40 percent of the usual flights in and out of Denmark would be back running by the end of 2020, with flying not returning to normal levels before 2022.