CA Health & Safety Code Section 113977

(a)

Except as specified in subdivision (b), an employee shall eat, drink, or use any form of tobacco only in designated areas where contamination of nonprepackaged food; clean equipment, utensils, and linens; unwrapped single-use articles; or other items needing protection cannot result.

(b)

A food employee may drink from a closed beverage container if the container is handled to prevent contamination of the employee’s hands, the container, nonprepackaged food, and food-contact surfaces.