5.2.7. The surfaces of materials and equipment that come into contact with eggs must be:(1) of non-corrodible materials;
(2) smooth and free from cavities or detachable particles;
(3) non-toxic and resistant to cleaning and disinfecting operations;
(4) unchangeable by eggs and made so as not to spoil eggs;
(5) free of constituents or residues that are agents of contamination of eggs.