Doors of a fire-isolated Open link in same pageexit must not be locked from the inside as follows:
In a Class 9a Open link in same pagehealth-care building.
In a Class 9c building.
on at least every fourth Open link in same pagestorey, the doors are not able to be locked and a sign is fixed on such doors stating that re-entry is available; or
an intercommunication system, or an audible or visual alarm system, operated from within the enclosure is provided near the doors and a sign is fixed adjacent to such doors explaining its purpose and method of operation.