All NM-B cable that I have seen recently uses a nylon jacket over the PVC conductor insulation. The nylon prevents the PVC insulation plasticizer from migrating into the EPS. The overall cable jacket also is a PVC material and you may have some plasticizer migration out of the jacket, but the jacket serves essentially no purpose after the cable is pulled and installed. Cracks in the cable jacket (due to long term loss of plasticizer) will not increase the potential fire hazard as long as the underlying conductor insulation remains intact and it should be with the nylon jacket. Also note that some NM-B wire designed for easy pulling has nylon incorporated into the outer cable jacket as well, further reducing the concern of plasticizer migration. |