Cal. Food & Agric. Code § 655

The occupancy of any space that is not required by the department for the commissions, divisions, bureaus, advisory boards, and services specified in Section 654 shall be confined to that of other functions of the department, of other state agencies, of official agencies cooperating with the department under agreement, or of official agricultural agencies of the state or county. Rentals comparable to the rentals that are authorized by Section 654 shall be charged for the space.