Passengers may carry small quantities of liquids, but only within separate containers each of which with a capacity not greater than 100 ml. These containers must be contained in a single, transparent, re-sealable plastic bag which itself must not exceed 1 litre in capacity (approximately 20 cm x 20 cm). The contents of the plastic bag must fit comfortably and the bag sealed. Each passenger may carry only one such bag of liquids. These regulations are applicable at all UK airports.