Why is it so important that cables and wires not only BE flame retardant, but also halogen-free?
Under no circumstances should cable and wire act as fuses enabling a fire to spread. They must not act as fuel for a fire, and should not release any dangerous substances. That is exactly what happens with materials whose flame retardation is based on halogens – i.e. fluorine, chlorine, bromine or iodine. Halogens are present in polymers like PVC, FEP, and PTFE. PUR, PP, P and TPE materials are often added as flame retardants. They can escape in case of a fire, and smother the surrounding flames. Later, however, they combine with water vapour to form acids that cause irritation to the eyes, skin and respiratory system, as well as attacking metal and glass.