The insulation commonly used on plenum-rated cable is _____.

Plenum-rated cable is designed for use in spaces that facilitate air circulation for heating and air conditioning systems, such as air ducts and ceilings. The insulation material must meet specific fire safety standards to prevent the release of toxic fumes when exposed to heat or flames.

PTFE (Teflon®) is a common insulation choice for plenum-rated cables due to its superior fire-resistant properties and low smoke generation. It is able to maintain its performance and structural integrity at high temperatures and offers excellent dielectric strength, making it ideal for minimizing risks in these environments.

In contrast, other materials such as PVC are not suitable for plenum spaces because they may emit harmful fumes when burned and do not meet the stringent fire codes required for plenum applications. Polyethylene and rubber also do not possess the same level of fire resistance and smoke reduction capabilities as PTFE. Thus, using PTFE ensures compliance with safety standards and protects both equipment and individuals in the event of a fire.