1.1   This part of ISO 5659 specifies a method of measuring smoke production from the exposed surface of specimens 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 under forced ventilation conditions, with or without the application of a pilot flame. This method of test is applicable to plastics and may also be used for the evaluation of other materials (e.g. rubbers, textile coverings, painted surfaces, wood and other building materials).