This edition has incorporated requirements for non-metallic raceways. This test is designed to provide information for evaluating the possibility of fire spreading in a plenum or other space used for environmental air along electrical wires or cables, optical-fiber cables or non-metallic raceways; or the possibility of high smoke levels being developed in the space when wiring or raceways are subject to fire exposure. The test method has been related to the results of tests on cables exposed to fires in simulated plenums. This test method is used to determine if a cable or non-metallic raceway qualifies for an FT-6 classification as specified in CSA C22.2 No. 0.3, Test Methods for Electrical Wires and Cables or CSA C22.2 No. 262, Optical Fiber Cable and Communication Cable Raceway Systems. This test method is for use in determining values of flame propagation distance and smoke optical density for electrical and optical-fiber cables and non-metallic raceways that are to be installed in ducts, plenums, and other spaces used for environmental air. It is not intended for use with cables enclosed in metallic raceways in those spaces. This method also determines values of flame propagation distance and smoke optical density for electrical and optical-fiber cables with combustible jackets or sheathes, and non-metallic raceways to determine their acceptability for use in buildings of non-combustible construction. This test method does not cover the construction requirements for cables and non-metallic raceways or their electrical and other performance requirements.