The Industrial Welfare Commission may employ necessary assistants, officers, experts, and such other employees as it deems necessary. All such personnel of the commission shall be under the supervision of the chairman or an executive officer to whom the chairman delegates such responsibility. All such personnel shall be appointed pursuant to the State Civil Service Act (Part 1 (commencing with Section 18000) of Division 5 of Title 2 of the Government Code), except for the one exempt deputy or employee allowed by subdivision (e) of Section 4 of Article VII of the California Constitution.