Specifies a method of measuring smoke production from the exposed surface of essentially flat materials, composites or assemblies, not exceeding 25 mm in thickness, when placed in a horizontal orientation and subjected to specified levels of thermal irradiance in a closed cabinet with or without the application of a pilot flame. Applies to all plastics and may be used for the evaluation of other materials. Meant for use in research and development and not primarily as a basis for ratings for building codes or other purposes.