All openings to the outside shall be effectively screened and such screens shall be kept in good repair. All screen doors shall open outward and shall be self-closing without leaving cracks through which flies and other insects may pass. All necessary procedures shall be carried out to control flies and the market shall be free from such at all times. Large fans protecting doorways may be used in lieu of screen doors, provided they are effective and kept in operation.History: Pub. Health Reg. 4, eff 13 Aug 64, § 5.