What does it mean for a cable to be plenum rated?

A plenum-rated cable is specifically designed and constructed for use in spaces where air circulates for heating and air conditioning systems, such as air ducts. It is made from materials that have low smoke and low flame characteristics, which helps reduce the risk of fire and smoke inhalation in the event of a fire. This certification allows the cable to be used in the plenum spaces of buildings, making it suitable for installation in areas where cables are exposed to airflow and could potentially pose safety risks.

The other options focus on different attributes that do not pertain to the specific requirements or conditions associated with plenum-rated cables. For instance, handling high voltages, being flexible for portable use, or possessing a longer lifespan pertains to other cable classifications and properties that are not the key distinction of plenum-rated cables.