California Code of Regulations
Title 8 - Industrial Relations
Division 1 - Department of Industrial Relations
Chapter 4 - Division of Industrial Safety
Subchapter 7 - General Industry Safety Orders
Group 1 - General Physical Conditions and Structures
Article 2 - Standard Specifications
Section 3216 - Exit Signs

(a) Luminance. Exit and directional signs shall have a luminance on the face of such signs of not less than 50 lux. The words used on such signs shall be in block letters at least 6 inches in height with a stroke of not less than 3/4 inch. Exception: Existing signs may have the word "EXIT" in lettering not less than 5 inches high with principal strokes of letters of not less than 1/2 inch. Letters shall be of such color or design as to be in strong contrast to the background of the sign. Arrows or other directional symbols shall be of equal visibility to that stipulated herein for letters.

(b) Location. Exit or directional signs, or both, shall be provided at every exit door, at the intersection of corridors, at exit stairways or ramps and at such other locations and intervals as are necessary to provide the occupants with knowledge of the various means of egress available. Exit or directional signs need not be provided for the following:

(c) Electrically Illuminated Signs. Exit and exit directional signs which are required to be electrically illuminated shall be lighted with two electric lamps, either one of which shall be sufficient to provide the required luminance on the face of the sign. NOTE: Radioactive isotope self powered signs with a luminance of not less than 0.02 lamberts during its useful life will be acceptable.

(Title 24, Part 2, Section 2-3312(c)(2).)