Cables For Indoor Applications
These cables are used exclusively within buildings and must have a flame-retardant jacket to fit this purpose. They may be deployed in duct (conduit) or cable tray. When routing a cable within a building, you will also need to factor in fire prevention requirements. These requirements differ per country and region of the world.
Plenum is defined as any enclosed area that facilitates environmental air handling. Cable jackets used in plenum spaces are rated for both flame and smoke generation.
Riser cable jackets are rated for flame generation and are held to a lower standard than plenum cables.