(1) Effective and safe control measures shall be utilized to minimize the presence of rodents, flies, roaches and other vermin on the premises. The premises shall be kept in such condition as to prevent the harborage or feeding of vermin. All openings to the outer air shall be effectively protected against the entrance of insects by self-closing doors, closed windows, screening, controlled air currents, or other effective means.

(2) Screening material shall be not less than 16-mesh to the inch or equivalent.

(3) Screen doors to the outer air shall be self-closing and screens for windows, doors, skylights, transoms and other openings to the outer air shall be tight fitting and free of breaks.

(4) All openings to the outside shall be effectively protected against the entrance of rodents.