Defines a small-scale laboratory screening method for comparison of the relative burning behaviour of specimens made from plastics and other non-metallic materials, in addition to their resistance to burn-through when exposed to a flame ignition source of 500 W nominal power. Applies to both solid and cellular plastic materials with an apparent density not less than 250 kg/m when determined according to ISO 845. Not applicable to thin materials which shrink away from the applied flame without igniting.