Cal. Health and Safety Code § 114252

In every room and area in which any food is prepared, manufactured, processed, or prepackaged, or in which equipment or utensils are cleaned, sufficient natural or artificial lighting shall be provided to produce the following light intensity, while the area is in use: (a) At least 10 foot candles for the following: (1) At a distance of 30 inches above the floor, in walk-in refrigeration units and dry food storage areas. (2) At a working surface on which alcoholic beverages are prepared or where utensils used in the preparation or service of alcoholic beverages are cleaned. (3) Inside equipment, such as reach-in or under-the-counter refrigerators. (b) At least 20 foot candles for the following: (1) At a surface where food is provided for consumer self-service or where fresh produce or prepackaged foods are sold or offered for consumption. (2) In server stations where food is prepared. (3) At a distance of 30 inches above the floor in areas used for handwashing, warewashing, and equipment and utensil storage, and in toilet rooms. (4) In all areas and rooms during periods of cleaning. (c) Except in server stations where food is prepared, at least 50 foot candles at a surface where a food employee is working with food or working with utensils or equipment such as knives, slicers, grinders, or saws where employee safety is a factor.