Finally, a third step connects the proxy data with the specific inputs and outputs in the ecoinvent database. This involves mapping how the proxy data is linked to the existing data in the ecoinvent database, both for environmental exchanges (inputs from and outputs to nature) and technosphere exchanges (inputs and outputs of man-made products and wastes). For example, the electricity input per amount of chemical is connected to the ecoinvent technosphere exchange electricity, medium voltage, and the uptake of cooling water from river and well is connected to the environmental exchange water, cooling, unspecified natural origin.