Cal. Lab. Code § 6304.5
It is the intent of the Legislature that the provisions of this division, and the occupational safety and health standards and orders promulgated under this code, are applicable to proceedings against employers for the exclusive purpose of maintaining and enforcing employee safety.
Neither the issuance of, or failure to issue, a citation by the division shall have any application to, nor be considered in, nor be admissible into, evidence in any personal injury or wrongful death action, except as between an employee and his or her own employer. Sections 452 and 669 of the Evidence Code shall apply to this division and to occupational safety and health standards adopted under this division in the same manner as any other statute, ordinance, or regulation. The testimony of employees of the division shall not be admissible as expert opinion or with respect to the application of occupational safety and health standards. It is the intent of the Legislature that the amendments to this section enacted in the 1999-2000 Regular Session shall not abrogate the holding in Brock v. State of California (1978) 8l Cal.App.3d 752.
Ca. Lab. Code § 6304.5