OSHA Subpart-D Occupational Health and Environmental Controls (Illumination)

1926.56(a) General. Construction areas, ramps, runways, corridors, offices, shops, and storage areas shall be lighted to not less than the minimum illumination intensities listed in Table D-3 while any work is in progress:

HAZARD: Employees exposed to struck by/vision obstruction hazards.   

ABATEMENT: General construction areas MUST be illuminated to not less than 5  foot-candles of illumination while any work is in progress.