This specification covers a thermoplastic jacketing compound substantially consisting of pigmented polyethylene for use in electrical wires and cables with specified nominal thicknesses and operating at specified voltages. Since the jacket material cannot be tested unless it has been formed around a conductor or cable, tests shall then be done on jacketed wires and cables solely to determine the relevant property of the jacket material and not to test the jacketed conductor or completed cable. Materials shall be suitably sampled and tested, and shall conform accordingly to the following physical and electrical properties: unaged tensile strength and elongation at rupture; tensile strength and elongation at rupture after air oven aging; absorption coefficient; heat distortion; environmental stress-cracking; surface resistivity; and U-bend discharge.