I am installing cable in a commercial business. Do I require a plenum (CMP) rated Ethernet cable?Updated 7 months ago

Perhaps. Plenum rated Ethernet cable is designed to be used in HVAC air handling spaces (like above drop ceilings and below raised floors) and your local codes likely dictate you MUST use it in those situations. Secondarily, if plenum Ethernet cable is required for any part of the installation your commercial contract should specify this as plenum rated Ethernet is considerably more expensive than riser rated Ethernet cable. Consult a local code inspector to be sure, as you may be forced to rework your installation, and your customer may lose their occupancy permit until the situation is rectified.