Section 72(9)(b) in The M.P. Factories Rules, 1962
(b)An exit may be doorway, corridor, passageway, to an external stairway or to a verandah or to an internal stairway segregated from the rest of building by fire resisting walls which shall provide continuous and protected means of egress to the exterior of a building or to an exterior open space. An exit may also include a horizontal exit leading to an adjoining building at the same level.