Cal. Health & Safety Code § 1234

(a) Smoking a tobacco product shall not be permitted in patient areas of a clinic except those rooms designated for occupancy exclusively by smokers.
(b) Clearly legible signs shall either:
1. (1) State that smoking is unlawful and be conspicuously posted by, or on behalf of, the owner or manager of such clinic, in all areas of a clinic where smoking is unlawful.
2. (2) Identify “smoking permitted” areas, and be posted by, or on behalf of, the owner or manager of such clinic, only in areas of a clinic where smoking is lawfully permitted.
  If “smoking permitted” signs are posted, there shall also be conspicuously posted, near all major entrances, clearly legible signs stating that smoking is unlawful except in areas designated “smoking permitted.”
(c) This section shall not apply to skilled nursing facilities, intermediate care facilities, and intermediate care facilities for the developmentally disabled.
(d) For purposes of this section, “smoking” has the same meaning as in subdivision (c) of Section 22950.5 of the Business and Professions Code.
(e) For purposes of this section, “tobacco product” means a product or device as defined in subdivision (d) of Section 22950.5 of the Business and Professions Code.