California Code, Labor Code - LAB § 887

(a) In order to maximize protection of public health and safety, emergency ambulance employees shall remain reachable by a portable communications device throughout the entirety of each work shift.

(b) If an emergency ambulance employee is contacted during a meal or rest period, that particular meal or rest period shall not be counted towards the meal and rest periods the employee is entitled to during his or her work shift.

(c) If an emergency ambulance employee is not contacted during a meal or rest period, that particular meal or rest period shall be counted towards the meal and rest periods the employee is entitled to during his or her work shift.