California Code, Health and Safety Code - HSC § 110805

(a) Except as otherwise provided in this section, no chopped or ground beef or hamburger that is offered for sale in any retail food production and marketing establishment or frozen food locker plant shall be advertised, labeled, or otherwise held out in any manner to describe or suggest its quality or relative leanness or fat content unless the label, advertisement, or other representation accurately discloses the maximum fat content thereof by the designation “Does not exceed __ percent fat”. However, in no case shall the fat content of any chopped or ground beef or hamburger exceed 30 percent fat, except in no case shall the fat content exceed 26 percent in the case of chopped or ground beef or hamburger processed from the primal cut of chuck when the primal cut designation is being used.

(b) No designation such as, but not limited to, “lean,” “super lean,” “premium,” “deluxe” or similar terms descriptive of quality, leanness, or fat content shall be included on the label unless the label also contains a fat-weight designation as specified in subdivision (a). However, as an alternative to including the fat-weight designation on the label, the fat-weight designation required by this section may be disclosed by means of a sign placed immediately adjacent to the counter on which the chopped or ground beef or hamburger is displayed.This sign shall be within plain view of prospective purchasers and shall display the appropriate designation specified in subdivision (a) in boldface print.

(c) Chopped or ground beef or hamburger that is processed from primal cuts of round or sirloin shall not be required to disclose the maximum fat content if there is no reference to leanness or other quality designation relating to fat content other than the primal cut from which the product is derived. If there is a reference to leanness or any other quality designation relating to fat content, the maximum fat designation shall be a fat-weight designation as specified in subdivision (a).

(d) It is unlawful and constitutes misbranding for any person to sell or offer for sale in a retail food production and marketing establishment or frozen food locker plant any chopped or ground beef or hamburger that is labeled in violation of this section.