The director or his or her duly authorized representative may enter, during reasonable business hours, any premises where milk, cream, or skim milk subject to the provisions of this chapter is produced, handled, distributed, sold, offered for sale, held for sale, or used for the inducement of the sale of another product to determine if such milk, cream, or skim milk has been properly decharacterized as provided in RCW 15.37.100 or rules adopted hereunder. No person shall interfere with the director or his or her duly authorized representative when he or she is performing or carrying out the duties imposed on him or her by this chapter or rules adopted hereunder.