Cal. Health & Saf. Code § 118885
Within indoor rooms, indoor chambers, or indoor places of public assembly in publicly owned buildings in which public business is conducted requiring or providing direct participation or observation by the general public there shall be a contiguous area of not less than 50 percent of the total area of the room, chamber, or place designated and posted by signs of sufficient number and posted in locations as to be readily seen by persons within the area, where the smoking of tobacco is prohibited while a public meeting is in progress. A public body, commission, agency, or other entity conducting a public meeting may waive the requirements of this section with respect to its own members, provided that the rights of nonsmoking members are not adversely affected.
Ca. Health and Saf. Code § 118885