It could contain spores of nasty bacteria named Clostridium Botulinum, which causes Botulism. Since normal bowel flora in children under 12 months old has not yet fully established, this bacteria could colonize and produce a toxin, which causes “infant botulism”. The most common form of botulism in the USA is infant botulism with about 100 cases per year.
2) Eggs (especially egg whites):
They are common sources of allergy and eczema.