For German DIN 4102 (B1), a material is classified as B1 if it fulfils the requirements of a B2-test and the ‘fire shaft’ test.
The residual length is minimum 150mm. The temperature of the smoke is maximum 200°C.
The time to reach the marked point is minimum 20 seconds. The paper doesn’t ignite. The droplets are burning for maximum 2 seconds.
A test specimen is hung vertically in a test cabinet with a burner in it. It is subjected simultaneously to a flame for 10 minutes and a constant flow of air from below. The temperature of the smoke and the undamaged length of the specimen are measured.
The test specimen is put on a specimen holder that is hung in a test cabinet. A burner flame is applied to it for 15 seconds. The time to reach a marked point is measured. Also the burning droplets are observed by means of a paper placed under the specimen.
The material is classified as: - B1 schwerentflammbare Stoffe; - B2 normalentflammbare Stoffe; - B3 leichtentflammbare Stoffe.