1.1 This International Standard specifiesa small-scale laboratory screening procedure for comparing the relative burning characteristics of horizontally oriented, small cellular plastic specimens having a density less than 250 kg·m-3 determined in accordance with ISO 845, when exposed to a small-flame ignition sourceNOTE Another International Standard exists covering fexible cellular plastic and cellular rubber: ISO 3582[2].1.2 This method of test is intended for quality assurance and limited product evaluation of cellular plastic materials under controlled laboratory conditions, and is not intended to assess the firebehaviour of e.g. building materials or furnishings under actual fire conditions1.3 The optional classificationsystem described in Annex A is intended for the pre-selection of cellular plastic materials for products, including the determination of the ranges of material parameters that give the same classification (see 6.1)