The Materialprüfungsamt Nordrhein-Westfalen, founded at Dortmund in 1947 and run as a state enterprise of North Rhine-Westphalia, testing, monitoring and certifying for more than fifteen thousand customers. It has operated a dedicated fire testing centre at its Erwitte branch since 1980, examining how materials, components and forms of construction behave in fire, alongside its wider work on building materials, safety glass, doors and gates and thermal insulation. It is a notified body in the field of the Construction Products Regulation. State ownership; testing is sold on the open market.