Low Smoke Zero Halogen (LSZH)-also known as LSOH, LS0H, LSFH, or OHLS-is a classification of cable jacket materials used in the wire and cable industry. LSZH jackets are made from thermoplastic or thermoset compounds that emit minimal smoke when heated and contain no halogens.
Most network cable jackets are made of polyethylene, PVC, or thermoplastic polyurethane. When ignited, chlorine-containing plastics release toxic hydrogen chloride, which forms hydrochloric acid upon contact with water. In contrast, LSZH materials do not release hydrogen halides or other acids during combustion.
LSZH materials reduce the emission of toxic and corrosive gases during burning. They are frequently used in poorly ventilated environments such as aircraft, train carriages, and ships. They are also widely used in the railway industry, where high-voltage lines and train-positioning signal cables run beneath the tracks. Using LSZH materials minimizes the accumulation of toxic gases in the event of fire or short-circuit damage to the cabling.
Protecting personnel and equipment from exposure to toxic and corrosive gases is a critical requirement in industries such as rail and shipbuilding; consequently, the use of LSZH materials for cable jackets is often mandated in these sectors.
