§ 59.203. Doors and windows.

 (a)  All openings to the outer air shall be effectively protected by:

   (1)  Screening;

   (2)  Effective electric screen panels;

   (3)  Fans or air curtains which provide sufficient air velocity so as to prevent the entrance of flies;

   (4)  Properly constructed flaps where it is impractical to use self-closing doors or air curtains; or

   (5)  Any effective combination of methods listed in paragraphs (1)—(4) or by any other method which prevents the entrance of flies.

 (b)  All outer doors shall be tight and self-closing. Screen doors shall open outward.

 (c)  All outer openings shall be rat-proofed to the extent necessary to prevent the entry of rodents.

   This section cited in 7 Pa. Code §  59.251 (relating to receiving station requirements); 7 Pa. Code §  59.252 (relating to transfer station requirements); 7 Pa. Code §  59.253 (relating to tank truck cleaning and sanitizing facilities requirements); and 7 Pa. Code §  59.702 (relating to buildings).