Nickel allergy caused by Jewels
| By H. Dubois, Chairman of the board, from a paper presented in the magazine « Le bijoutier », No 602, october 2000. |
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Jewels made of bulk silver are very popular and a broad choice is available on the market. Good vendors are proposing bulk silver with a surface finish of 1000/000 fine silver and a passivation layer of rhodium coating. In such cases, of course, there is no risk of nickel allergy. On the other hand side, there are other vendors providing bulk silver jewels which may cause nickel allergy. What is the reason for it ? |
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Even if the bulk material is made of suitable alloy with a correct composition, there is a typical process used to increase brightness and reduce polishing costs ; by bringing a nickel underlayer by electrodeposition, followed by a thin 1-3 microns fine silver top coating.
Thickness measurements, carried out by metallographic cross sections may reveal a nickel underlayer of about 10 microns of bright nickel.
By wearing such items, the fine top silver layer will rapidly dissapear by mechanical wear, leading sweat to be in contat with the nickel coating, consequently producing nickel salts. Then allergy may be developped. |
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This is an aim of Laboratoire Dubois to support and advise all stakeholders in this respect. Therefore, in order to minimising any health issue, we recommend the distribitors of jewels to follow the following advices : |
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Compulsory request to suppliers that silver or silver coated jewels are free from nickel and in accordance with the
European regulation
about nickel release. |
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To undertake statistical checks about the nickel free requirement with the support of an independent, accredited laboratory. |
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