9 CFR § 590.538 - Defrosting facilities.
(a) Approved metal defrosting tanks or vats constructed so as to permit ready and thorough cleaning shall be provided.
(b) Frozen egg crushers, when used, shall be of approved metal construction. The crushers shall permit ready and thorough cleaning and the bearings and housing shall be fabricated in such a manner as to prevent contamination of the egg products.
(c) Service tables shall be of approved metal construction without open seams and the surfaces shall be smooth to allow thorough cleaning.