5.2.2. In case of failure of the power required for the lighting of exits during occupancy of the establishment, an emergency lighting system shall:
(a) be provided for the lighting of exits, and the notices indicating exits, passageways, corridors and alleys leading directly to exits;
(b) maintain in areas required in paragraph a a level of illumination of 50 lux for a period of at least half an hour at floor level; and
(c) be inspected monthly.