California Code, Labor Code - LAB § 6412

No report of injury or illness required by subdivision (a) of Section 6409.1 shall be open to public inspection or made public, nor shall those reports be admissible as evidence in any adversary proceeding before the Workers' Compensation Appeals Board.  However, the reports required of physicians by subdivision (a) of Section 6409 shall be admissible as evidence in the proceeding, except that no physician's report shall be admissible as evidence to bar proceedings for the collection of compensation, and the portion of any physician's report completed by an employee shall not be admissible as evidence in any proceeding before the Workers' Compensation Appeals Board.