The main point is fire doors are there to keep you safe from fire. On installation fire doors will be certified by the installer as when installed correctly the doors are able to contain a fire for 30, 60, or 90 minutes depending on the need 0f the door set.  As time goes on

Fire door inspections are an important part of your building's passive fire protection. A good well-maintained fire door will act as a vital fire barrier between a fire and the building occupants, as well as ensuring your escape routes remain clear of fire and smoke. You should appoint a trained specialist to carry out