Finnair and LATAM airlines have ban the use of cloth masks on flights. Cloth masks are allowed in the United States; however, some airlines have changed their mask mandates.
Delta prohibits bandanas, scarves, and masks with exhaust valves, slits or holes. United has banned face shields alone and bandanas. Southwest prohibits bandanas, scarves, ski masks and single layer masks. American bans exhaust valves, scarves, bandanas and gaiters. Jet Blue does not allow masks connected to tubing or battery-operated filters. Hawaiian Airlines won’t allow scarves, ski masks or bandanas.
Currently, a federal mask mandate is in place in airports and on planes. It is important to double check and make sure the mask you have will be acceptable before heading to the airport.