California Code, Labor Code - LAB § 7861

(a) Each employee whose primary duties include the operating or maintenance of a process, and each employee prior to assuming operations and maintenance duties in a newly assigned process, shall be trained in an overview of the process and in the operating procedures as specified in Section 7860. The training shall include emphasis on the specific safety and health hazards, procedures, and safe practices applicable to the employee's job tasks.

(b) Refresher and supplemental training shall be provided to each operating or maintenance employee, or both, and other worker necessary to ensure safe operation of the facility and on a recurring regular schedule as determined adequate by the board.

(c) The employer shall ensure that each worker necessary to ensure safe operation of the facility has received and successfully completed training as specified by this section. The employer, after the initial or refresher training shall prepare a certification record which contains the identity of the employee, the date of training, and the signature of the person conducting the training. Testing procedures shall be established by each employer to ensure competency in job skill levels and safe and healthy work practices.