ISO ignitability test and proposed criteria

Having characterized the current classification of building materials in Scandinavia the use of the International Standards Organization ignitability test for classifying coverings, linings and materials is discussed. Further evidence for the assumption of a linear function for 1/ t ig (where t ig is the time for sustained surface ignition) versus irradiance was gained for a number of materials, mainly wood‐based. This has been utilized in forecasting the ignitability behaviour in the new test by correlation of classes. Through definition of two borderline segments a simple table giving proposed criteria for t ig is obtained.