Cal. Food & Agric. Code § 62712
(b) For the purposes of enforcing this chapter, the secretary, through his or her duly authorized representatives and agents, shall have access to the records of every producer and handler. The secretary shall have at all times, free and unimpeded access to any building, yard, warehouse, store, manufacturing facility, or transportation facility in which any market milk or market milk product is produced, bought, sold, stored, bottled, handled, or manufactured.
Any books, papers, records, documents, or reports made to, acquired by, prepared by, or maintained by the secretary pursuant to this chapter, which would disclose any information about finances, financial status, or worth, composition, market share, or business operations of any producer or handler, excluding information that solely reflects transfers of production base and pool quota among producers, is confidential and shall not be disclosed to any person other than the person from whom the information was received, except pursuant to the final order of a court with jurisdiction, or as necessary for the proper determination of any proceeding before the secretary.