Low smoke zero halogen or low smoke free of halogen (LSZH or LSOH or LS0H or LSFH or OHLS) is a material classification typically used for cable jacketing in the wire and cable industry. LSZH cable jacketing is composed of thermoplastic or thermoset compounds that emit limited smoke and no halogen when exposed to high sources of heat, e.g. flame.[1]
Most network cables are insulated with polyethylene, PVC or Thermoplastic Urethane (TPU) . In a fire, a halogen-containing plastic material releases, e.g. hydrogen chloride, a poisonous gas that forms hydrochloric acid when it comes in contact with water. Designated Halogen-free cables, on the other hand, do not produce a dangerous gas/acid combination or toxic smoke when exposed to flame.
Low smoke zero halogen cable reduces the amount of toxic and corrosive gas emitted during combustion. This type of material is typically used in poorly ventilated areas such as aircraft or rail cars. Low smoke zero halogen is becoming very popular and, in some cases, a requirement where the protection of people and equipment from toxic and corrosive gas is critical.
Other benefits of halogen free cable include: