9 CFR § 590.550 - Washing and sanitizing room or area facilities.
(a) This room or area shall be well lighted, and of sufficient size to permit operators to properly wash and sanitize all equipment at the rate required by the size of the operation. Adequate exhaust shall be provided to assure the prompt removal of odors and vapors and the air flow shall be away from the breaking room. If the washing and sanitizing is not done in a separate room, it shall be in an area well segregated from the breaking areas and be well ventilated with air movement directed away from the breaking operations so that odors and vapors do not permeate the breaking areas.
(b) Ceiling and walls shall have a surface of tile, enamel paint, or other water-resistant material.
(c) Floors shall be adequately sloped for proper drainage, be free from cracks or rough surfaces where water and dirt could accumulate and the intersections with walls shall be impervious to water.
The following state regulations pages link to this page.