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.