A Bunded Oil Tank simply consists of a tank within a tank. The fuel is stored in the inner tank and the outer tank acts as a failsafe so that in the event of a spillage, excess fuel will collect in the outer tank - thus averting a pollution incident.

Bunded Oil Tanks have been proven to significantly reduce the risk of pollution at oil storage installations. They are a requirement at commercial, industrial, institutional and commercial premises; all installations in the Channel Islands; and, at most domestic installations in the United Kingdom and Republic of Ireland.

A Single Skin Oil Tank consists of a single rotationally moulded container, in which fuel is stored. Single Skin Oil Tanks do not incorporate any form of secondary containment and therefore in the event of a spillage, ordinarily a pollution incident will result.

Single Skin Tanks Plastic Oil Tanks are suitable only for installation at the very small number of domestic installations where a Bunded Oil Tank is not a legal requirement.