A container (22) includes a shell (24) made from a polymer, for example PET, and incorporating a catalyst, for example a palladium catalyst. A closure (40) incorporates a plug which includes a source of hydrogen, for example a hydride. In use, with container (22) including a beverage and closure (40) in position, the headspace in the container will be saturated with water vapor. This vapor contacts the hydride associated with plug (42) and as a result the hydride produces molecular hydrogen which migrates into the polymer matrix of shell (24) and combines with oxygen which may have entered the container through its permeable walls. A reaction between the hydrogen and oxygen takes place, catalyzed by the catalyst, and water is produced. Thus, oxygen which may ingress the container is scavenged and the contents of the container are protected from oxidation.