Swedish airport operator LFV says liquids and gels are now banned from hand baggage. The rule applies to drinks, shampoo, suncream, hairgel, toothpaste and substances of a similar consistency.
The restrictions imposed by LFV follow new rules from the US Transportation and Safety Administration.
Authorities in the UK say terrorists planned to blow up planes by mixing different liquid ingredients that by themselves would not be considered harmful, and then detonating it with some sort of electronic device.
Food and drink for young children who are travelling has been excluded from the ban, as has prescription medicine, as long as it is marked with a label bearing the passenger’s name. Insulin and other important non-prescription medicine is also excluded.
People flying from Copenhagen to the US have been told to contact their airline for more information.
Passengers leaving the UK were facing even tougher restrictions on hand luggage, but the rules do not affect incoming flights to Britain.