Classified civil service -- Places of employment constituting classified civil service -- Appointments to and from classified civil service

(1) The classified civil service shall consist of all places of employment now existing or hereafter created in or under the police department and the fire department of each first or second class city that establishes a civil service commission and the health department in each first class city that establishes a civil service commission, except the head of the departments, deputy chiefs of the police and fire departments, and assistant chiefs of the police department and fire department in cities of the first and second class, and the members of the board of health of the departments. (2) No appointments to any of the places of employment constituting the classified civil service in the departments shall be made except according to law and under the rules and regulations of the civil service commission. (3) The head of each of the departments may, and the deputy chiefs of the police and fire departments and assistant chiefs of the police and fire departments shall, be appointed from the classified civil service, and upon the expiration of the term or upon the appointment of a successor shall be returned thereto.