Smells sulfurous, rotten, or unusually strong when peeled or cut
Has a slimy, sticky, or tacky surface
Shows mold or any fuzzy growth
Has an off color such as green, gray, pink, or black in the egg white or yolk
Has a very soft, mushy, or rubbery texture that seems abnormal
Leaks liquid or has a watery, broken-down interior
Tastes sour, bitter, or otherwise unpleasant
Was left unrefrigerated for more than 2 hours, or more than 1 hour in hot weather
Has been stored in the refrigerator for more than 1 week after boiling
Cracks were present and the egg was not refrigerated promptly