Quote:
"Class A eggs shall have the following quality characteristics:
(a) shell and cuticle: normal shape, clean and undamaged;
(b) air space: height not exceeding 6 mm, stationary; however, for eggs to be marketed
as �extra� it may not exceed 4 mm;
(c) yolk: visible on candling as a shadow only, without clearly discernible outline, slightly
mobile upon turning the egg, and returning to a central position;
(d) white: clear translucent;
(e) germ: imperceptible development;
(f) foreign matter: not permissible;
(g) foreign smell: not permissible.
Class A eggs shall not be washed or cleaned, before or after grading"
As long as those criteria are met, eggs are classed as Class A. The conditions under which they were produced are irrelevant.
Source of quote:
http://www.defra.gov.uk/corporate/regulat/form s/livestock_prods/eggs/emr1.pdf
Chris