Cal. Health & Safety Code § 113984.1

Consumer access to a food facility through the food preparation area is permissible, at the discretion of the permitholder, if ready-to-eat foods are prepared in approved areas separated from sources of contamination by a space of at least three feet from the consumer and in areas that are separate from raw or undercooked foods. The route of access shall be separated from the required space by a rail or wall at least three feet high or otherwise clearly delineated.