This part of ISO 5660 specifies a method for evaluating materials and products that produce low levels of heat release when exposed to high heat flux (i.e. irradiance levels) typical of fully developed fires. It differs from ISO 5660-1 by prescribing items such as specific specimen size, specimen holder, specimen orientation, volumetric flow rate for O2 analyses and irradiance levels at which testing is conducted. This test method is intended for use on products and materials that contain only small amounts of combustible elements, e.g. test specimens that yield a total heat release of < 15 MJ m-2. NOTE The test method for specimens that yield moderate to high total heat release is described in ISO 5660-1. The information obtained from the test method in this part of ISO 5660 can also be used for fire safety engineering purposes