You need to run cable through the airspace between offices, what type of cable is required to do this safely?
Answer Description
Plenum cable is jacketed in a fire-retardant plastic jacket.
Wikipedia
Plenum cable is electrical cable that is laid in the plenum spaces of buildings. In the United States, plastics used in the construction of plenum cable are regulated under the National Fire Protection Association standard NFPA 90A: Standard for the Installation of Air Conditioning and Ventilating Systems. All materials intended for use on wire and cables to be placed in plenum spaces are designed to meet rigorous fire safety test standards in accordance with …
Plenum cable - Wikipedia, the free encyclopedia