Homes, agriculture and industry generate large quantities of biodegradable waste products that, when managed improperly, can cause enormous environmental impacts. The reuse of these wastes, which are currently often disposed of as residues, is one of the key principles of the EU's December 2015 Circular Economy package, which involves moving away from the traditional linear economy model and replacing it with a new model of society involved in using and optimising raw materials and material resource flows.