California Code, Health and Safety Code - HSC § 118915

(a) Except as provided in subdivision (b), no person shall smoke any tobacco product in any retail food production and marketing establishment, as defined in Section 28802, during the hours the establishment is open to the public.

(b) The provisions of subdivision (a) shall not apply to that portion of an establishment subject to Section 118900 nor to an area of an establishment set aside for employee smoking and not open to the public.