Definitions for "Plenum Cable"
Cable that has an outer sheath coated with Teflon as a fire retardant. It will not give off toxic fumes or smoke when burned. It will also accept a higher temperature then regular PVC coated cable. Plenum cable is usually used in the plenum space of a building which is between the actual ceiling and the drop ceiling.
Cable having a covering (jacket ) that meets UL specifications for resistance to fire.
Cable made of fire-retardant material that generates little smoke. These cables are installed in plenum air ducts.