FR = Flame Retardant
After a possible ignition source is removed, the material normally extinguishes itself. Expansion of fire is impaired in this way.
NC = Non Corrosive (halogen-free) In the event of fire, halogen-containing substances coming into contact with water (fire protection water) form corrosive gases, which attack other materials, for example, in electronic devices. High levels of consequential damage are not uncommon.
Each quality may be required individually or as a combination. Caution: "Halogen-free" is not identical to "FRNC"! Different materials and different cable structures lead to a differing rating of the behaviour in the case of fire. There are standards, to which the cables are assigned after relevant tests. These standards are prepared at the national, European and international level, however the criteria are not always identical and, thus, not readily comparable. In general, the requirements of the cable type in compliance with the relevant standard must be observed!