An estimated 14% of people are allergic to nickel to some degree. It was closer to 10% before the piercing craze took hold. Nickel's ability to sensitize and its carcinogenicity are reasons why the European Union has a regulation called the Nickel Directive that prohibits metal items such as jewelry, glasses frames and watch bands, from leaching even tiny amounts of nickel. But in US colleges, the casting of nickel silver alloy is common in art and jewelry studios.
Monona
In a message dated 1/30/2012 8:48:51 PM Eastern Standard Time, mwright**At_Symbol_Here**USW.ORG writes:
Nickel in certain forms is carcinogenic, but I can't see how the nickel cladding could get hot enough to fume off. Can you see visible corrosion or rub off visible nickel oxide?
Some people are allergic to nickel - usually it's mild. Unless they are in close contact with it, like touching it frequently, it shouldn't occur - unless the cladding is oxidizing, undergoing some other reaction, or fuming off, all of which seems unlikely.
Michael J. Wright
Director of Health, Safety and Environment
United Steelworkers
5 Gateway Center
Pittsburgh, PA 15222
Work (412) 562-2580
Cell (412) 370-0105
Fax (412) 562-2584
mwright**At_Symbol_Here**usw.org