This standard specifies the general part of a method common to all bedding items. EN ISO 12952-4 describes the specific parts of the test method for bedding items, which can normally be placed on a mattress. A test specimen placed on a testing substrate is subjected to a small open flame placed on top of and/or below the test specimen. Any progressive smouldering and/or flaming is noted. Where the actual mattress is known, it can replace the testing substrate.