The smoke performance of jackets and insulations for wire and cable using UL 1685 “LS” designation

The purpose of this paper is to educate the reader concerning the smoke performance of available wire and cable burned in the approved UL Standard 1685. The paper: defines and relates the technical terms “halogen”, “low halogen” and “nonhalogen”, “smoke, “low smoke” and “LS rating”; describes apparatus to perform UL 1685 and defines passing smoke levels; shows test smoke levels of different wire and cable constructions compared to the standard; and shows relevance of these tests to electronic gear. The issues surrounding smoke can be put on a performance basis, using new technical standards for measurement. Previously, manufacturers have used the term “low smoke”. This paper has direct application to wire and cable specifications for wire used in transit tunnels, control rooms and also any applications having enclosed spaces and large amounts of wire and cable