Each food service establishment shall be provided with adequate, conveniently located toilet facilities for its employees; provided, that adequate and convenient toilet facilities may not be required for employees of a mobile food service establishment when the food offered for sale from such establishments is prepared and packaged in individual portions at a fixed food service establishment operating under valid permit. Toilet fixtures shall be of sanitary design and readily cleanable. Toilet facilities, including rooms and fixtures, shall be kept in a clean condition and in good repair. The doors of all toilet rooms shall be self-closing. Toilet tissue shall be provided. Easily cleanable receptacles shall be provided for waste materials, and such receptacles in toilet rooms for women shall be covered. Where the use of non-water-carried sewage disposal facilities have been approved by the health officer, such facilities shall be separate from the establishment. When toilet facilities are provided for patrons, such facilities shall meet the requirements of this chapter. (1961 code § 6.06.100.)