In order to ensure that EU Member States maintain emergency stocks of oil or petroleum products to be used in case of a supply crisis, a mandatory regime of compulsory oil stocks has existed since 1968. Member States have implemented different systems to manage their obligations: some rely on government held stocks, others established special stockholding agencies while yet others rely on stocks held by industry.
In March 2007, The European Council began to review the EU oil stockholding system. The Council had the goal to increase the availability of oil in the event of a crisis and harmonise mechanisms with the system administered by the International Energy Agency (IEA). In September 2009, the European Council adopted a new Directive (2009/119/EC) which replaced previous European legislation (Directive 2006/67/EC). The new directive was to be transposed into national legislation by Member States by 31 December 2012.