Q: Does CMP (plenum) rated category cable have PVC in it?
A: Yes. Unless explicitly noted, CMP rated cables utilize a PVC jacket, similar to that of a CMR (riser) rated cable. The CMP rated cable will have more flame retardant in the PVC. The CMP rated cable will also utilize different materials for the insulation that will assist it in passing the more rigorous plenum flammability test required by U.S. national electrical code. Sometimes people refer to CMR cable as PVC. Since both CMP and CMR cables utilize a PVC jacket, it is important when purchasing the cable to clarify which cable you want.