All shucking pails, opening knives, blowers, skimmers, tanks, tubs, trays, measures, colanders, paddles, or other equipment or utensils which may come in contact with shucked shellfish shall be made of not readily corrodible, smooth, impervious material and shall be constructed in such a manner as to eliminate grooves, seams, and cracks where foreign particles, dirt, and slime might collect. Perforations in the skimmers, colanders, and blower trays shall be smooth to facilitate cleaning. Skimmers, ladles, and colanders of wire-mesh construction are not permitted. The top rim of every tank, tub, and tray shall be at least 30 inches above the floor.