Section 9A. Every room used for the manufacture of flour or meal food products shall, if required by the board of health, have an impermeable floor constructed of cement or tiles laid in cement, and an additional floor of wood properly saturated with linseed oil. The walls and ceiling of such room shall be plastered or wainscoted, and, if required by the board of health, shall be whitewashed at least once in three months. The furniture and utensils therein shall be so arranged that they and the floor may at all times be kept clean and in good sanitary condition.