Oil stocks is an amount of oil products which are at the disposal or under control of the state and formed for the purpose of ensuring the security or subsistence of the population in order to perform international agreements pertaining to the supply of energy and fuel. The purpose of oil stocks is to avoid or reduce disturbances in economic activities in the event of disruption in the supply of oil products (delivery difficulties), as a result of which the established stocks mean ensuring the security of the state's economic activities. Literally, oil stocks may be considered a buffer from which fuel companies operating in Estonia will be able to purchase fuel in the event of a crisis – for instance, if something like the Arabian oil embargo of 1973 should recur. Most of the fuel consumed in Estonia is brought from Lithuania, but in the event of liquid fuel delivery difficulties the aforementioned buffer will replace the ordinary sources of delivery.
The European Union has clearly declared that imported oil products are of great importance among the energy resources of the Community. Even short-term delivery difficulties or a considerable rise in oil prices could cause serious disturbances in the economic activities of the Community. In such circumstances the EU must be able to prevent or at least alleviate any adverse effects. Thus, the purpose of stockpiling 90 days' fuel stocks is to ensure sustainable economic activities in the event of unforeseen delivery problems of oil products.