IP or 'Ingress Protection Code' is defined in IEC standards which classify and rates the degree of protection provided by mechanical casings and electrical enclosures against intrusion, dust, accidental contact and water.

The fuse board is required to have a minimum IP rating to prevent a person from touching live parts and to prevent conductive and combustible materials from falling into the fuse board. If you notice a gap or hole large enough to fit a finger in it, it is likely that it is not safe or compliant with current IET wiring regulations.

Fire protection should also be installed at cable entries to ensure the fire cannot spread.

If in doubt give your local electrician a call for further advice.