Fire dampers work through the intumescent material inside the damper itself. This fire-resistant material reacts to the detection of heat and smoke by automatically closing the device to prevent free passage of smoke or fire. Creating as compartment in itself will eventually burn out, but it will give people and emergency services time to react accordingly.

A smoke damper is designed to prevent the flow of rapidly moving smoke. Fire dampers are designed to prevent the spread of fire inside the ductwork.

From the 1st July 2013, became a legal requirement under the Construction Products Regulation that all new fire and smoke dampers have to be fire rated and CE marked.