Chrome is plated over, or contains nickel, among other things. People with nickel allergy can have serious reactions from anything that contains free nickel. I don't really know if the corroded shakers would be a health hazard for the non-allergic, but have read that ingesting too much nickel can cause health problems, because nickel is toxic, as well as allergenic. There would also be other metals used, that may be risky.
