There is no universal exact classification or specification which is used for such materials. Even legislative authorities have not yet established any exact guidelines on the type and composition of alternative fuels. The first approaches towards classification or specification are to be found in the Federal Republic of Germany (Bundesgütegemeinschaft für Sekundärbrennstoffe) as well as at European level (European Recovered Fuel Organisation). These approaches which are initiated primarily by the producers of alternative fuels, follow a correct approach: Only through an exactly defined standardisation in the composition of such materials can both production and utilisation be uniform worldwide.