Lufthansa is tightening its mask policy amid the coronavirus pandemic and will no longer permit fabric masks to be worn on their aircraft.

Beginning Feb. 1, the German airline would require passengers to wear only surgical masks, FFP2, KN95, and N95 masks.

The company said that travelers must wear masks at all times, including boarding, while onboard, and departing the aircraft.

Passengers are still permitted to wear visors and masks with valves, the company said.

Exceptions would be accepted to the new regulation only if a passenger presents a negative COVID-19 test result that is not older than 48 hours and a medical certificate on the Lufthansa Group form.

The new rule is applicable on all flights to and from Germany.