Joe,
Unfortunately there are several answers to your question, all depending on what industry you are working in (General, Construction or Maritime). Since this is an electrical contractor forum I will cover OSHA construction industry standard 29CFR 1926.56. Here is the link to that standard.
http://www.osha-slc.gov/OshStd_data/1926_0056.html If you are employed in the maritime industry then you would fall under 29CFR1917.123. Here is a link to that standard
http://www.osha-slc.gov/OshStd_data/1917_0123.html OSHA bases their illumination requirements on the American National Standards Institute and Illuminating Engineering Society standard, ANSI/IES-RP-7-1991 which is copyrighted by IESNA. It may be purchased by Order # ANSI-RP-7-91 from IESNA, 345 East 47th Street, New York, NY 10017. I would strongly suggest that this be used to assure proper lighting is maintain in all workplaces.
If this does not answer your question, please contact me via e-mail or by posting on this board.
Thanks!
Bryan