Section 001-342-III - Construction and Design of PlantsA. Floors at all plants shall be smooth and easily cleanable and made of concrete, tile or a substance impervious to water. All floors must be properly trapped and sloped to drains with an adequate slope to facilitate the removal of standing water.B. Walls and ceilings at all plants shall be constructed of impervious smooth material so to be readily cleanable. They shall be kept clean and in good repair. Floor and wall junctures shall be effectively sealed.C. Exterior openings at all plants shall be protected by the following measures: (1) Filling or closing holes and other gaps along floors, walls and ceilings;(2) Closed, tight fitting windows;(3) Solid self closing, tight-fitting doors; and/or(4) 16 mesh or 25.4 mm (16 mesh to 1 inch) screens on windows and doors.D. Light bulbs, fixtures, skylights, or other glass at all plants suspended over any exposed food in any step of preparation or storage, shall be of the safety type or otherwise protected to prevent food contamination in case of breakage.01-001 C.M.R. ch. 342, § III