The Department for Transport on Monday announced new rules on items that passengers may take aboard aircraft in their hand luggage. The new rules were effective immediately, but will not be implemented at Heathrow and other major airports until Tuesday. Each passenger is permitted to carry one item of cabin baggage through the airport security search point. The dimensions must not exceed 45 centimeters long, 35 cm wide and 16 cm deep (17.7 by 13.7 by 6.2 inches). Those limits include wheels, handles, side pockets, etc. Other bags, such as handbags, may be carried within the single item of cabin baggage. No liquids of any type may be carried through the airport security search point except: - Prescription medicines in liquid form sufficient and essential for the flight, and must be verified as authentic. - Baby milk and liquid baby food. Contents of each bottle or jar must be tasted by the accompanying passenger in the presence of security officers. Prohibited liquids include gels, pastes, lotions, liquid/solid mixtures and the contents of pressurized containers, e.g. toothpaste, hair gel, drinks, soups, syrups, perfume, deodorant, shaving foam, aerosols, etc. Passengers are encouraged not to carry on items capable of containing liquids. Passengers on flights to the United States will be subjected to secondary search at the gate. Any liquids will be removed from the passenger.