§ 20. Access to place of business. The commissioner, each deputy commissioner and the directors, counsel, experts, chemists, agents and other officers and employees of the department shall have full access to all places of business, factories, farms, buildings, carriages, cars and vessels used in the production, manufacture, storage, sale or transportation within the state of any dairy products or any imitation thereof, or of any article or product with respect of which any authority is conferred by this chapter on the department. They may examine and open any package or container of any kind containing or believed to contain any article or product, which may be manufactured, sold or exposed for sale in violation of the provisions of this chapter, or of the rules of the department, and may inspect the contents therein, and take therefrom samples for analysis.