Low smoke zero halogen (LSZH or LSOH) is a type of plastic used in the wire and cable industry for cable jacketing. LSOH cable jacketing is custom compounded to produce minimal smoke and no halogen when exposed to fire.
Most network cables (CAT5, CAT6, etc.) are insulated with poly vinyl chloride (PVC), polyethylene, or thermoplastic urethane (TPU). In a fire, halogen-containing plastic releases hydrogen chloride, a poisonous gas that forms hydrochloric acid when it comes in contact with H2O. Zero Halogen cables do not produce this toxic combination of gas, acid, and smoke when exposed to flame.
Since no harmful toxins are actually released, LSOH material is usually used in poorly ventilated areas such as plenum, aircraft, rail cars, and tunnels in which smoke is likely to both build up and come into contact with people. Low smoke zero halogen material is becoming very popular, and can be required when the safety of people and equipment is critical. Low Smoke Zero Halogen compound also has the added benefit of complying with the European Union’s Restriction of Hazardous Substances (RoHS) directive and similar North American safety and environmental standards.
In 1995 S&E developed our first commercial zero Halogen compound, which we still produce in large quantities. Our innovative line of LSOH compounds fall into two families:
- Extrusion grades – By using special grades of metal hydroxide and very unique resin combinations, we were able to develop the series of one of the most flexible zero halogen compounds on the market, having a -50C to 90C+ continued use temperature rating, as well as exceptional physical and processing characteristics.
- Molding Grades – Using advanced phosphorus-nitrogen chemistry, we developed a high grade FR intumescent compound with UL 94 VO rating down to 40-45 mils. Other special characteristics of these compounds are good thermostability and low moisture sensitivity.
We believe we will continue to see increased adoption of zero halogen compounds and alloys, and we are continuously working on new grades, which meet the most critical and demanding application requirements.