What are Plenum cables used for?

Plenum-rated cables are specifically designed for use in the plenum spaces of commercial buildings, which are used for air circulation. These cables feature outer jackets made from materials that do not release toxic fumes when exposed to fire, ensuring safer conditions in these air-handling areas. While it's acceptable to use higher-rated cables in lower-risk areas, such as those with less stringent fire requirements, you should never use cables rated for lower-risk areas (like CL2 or CL3) in plenum spaces. This includes CMP (Communications Plenum) cables, which are unsuitable for less demanding environments.