Low Smoke Cables are cables which produce low smoke when they burn. They are used in closed areas where ventilation is less. When a cable burns as a result of a short circuit or high current, the smoke emitted by the insulation is extremely dense.
In emergency situations, this density smoke can reduce visibility and can impede evacuation. The dense smoke also contains harmful chemicals which may affect breathing.Hence, many installations stipulate low smoke cables.
Halogens are a group of elements. Fluorine, Bromine, Chlorine and Iodine are the common halogens. When a material such as PVC burns, it releases halogen gas. Chlorine gas, for instance, forms hydrochloric acid on contact with moisture. This can be harmful to health. Zero Halogen cables are made of materials which will not produce any halogen on burning.