The total weight of materials, extracted from the domestic environment and imported from other countries, which have been used in the domestic economy , then flow to the domestic environment. These flows occur at the processing, manufacturing, use, and final disposal stages of the economic production-consumption chain. Exported materials are excluded because their wastes occur in other countries. The sum of domestic processed output and domestic hidden flows. This indicator represents the total quantity of material outputs to the domestic environment caused directly or indirectly by human economic activity.
Gateways are the first point of entry of a material flow into the environment.
Both DPO and TDO can be disaggregated to show the quantity of material output generated by each sector. Dissipative losses such as rubber worn away from car tires, particles worn from friction products such as brakes and clutches, and solvents used in paints or other coatings. The balance is the net addition to stock.