A fire door is a door with a fire-resistance rating (sometimes referred to as a fire protection rating for closures)
used as part of a passive fire protection system to reduce the spread of fire and smoke between separate compartments
of a structure and to enable safe egress from a building or structure or ship. In North American building codes, it, along with fire dampers,
is often referred to as a closure, which can be derated compared against the fire separation that contains it, provided that this barrier is not a firewall or an occupancy separation.