California Code, Food and Agricultural Code (Formerly Agricultural Code) - FAC § 18990

(a) Each person, before acting as a livestock meat inspector in a livestock custom slaughterhouse, shall apply to the director and shall receive from the director a license after passing an examination and a demonstration that shows the applicant's ability to understand laws and regulations which pertain to meat inspection and a practical knowledge of all the following:

(b) Applicants shall not be less than 18 years old.