Material flow in the framework of environmental statistics focuses on mass of chemicals and materials that flow in or out of the economy. The focus is on material flow that is directly connected with processes and investments that originate in the economy, rather than material flow that is due to natural origins. The main components of the material flow are management of solid waste, treatment of waste water and emissions of gasses (found in it‘s own category). Additionally numbers for import, export and water consumptions are collected, but these numbers are connected with environmental load in a wider sense.