These three cable jackets represent different fire-retardant level.
OFNR cable is resistant to oxidation and degradation. It gives off heavy black smoke, hydrochloric acid and other toxic gases when it burns. It is fine to use as a patch cord or for single in-wall runs. If you want to use it in a building, the building must feature a contained ventilation system and has good fire exits.
OFNP cable has fire-resistance and gives low smoke when it burns. It can be used as a substitute for PVC (OFNR) cable since its fire-resistance is the highest. It’s designed for the movement of environmental air and commonly used for vertical runs between floors.
LSZH cable is more rigid and less flexible than PVC (OFNR) cable. It has a flame-resistant jacket that doesn’t emit toxic fumes even if it burns. For confined aerospace, marine, and military applications, getting outside isn’t always an option and in cases of rooms where it is not easy to get out quickly, you should always use LSZH cable.p