We have been producing and selling optical frames made from SPM several decades in the Japanese market.
SPM is excellent about the affinity with body, it was used widely for accessories, straps of wristwatches, dental use, and for a plastic surgery.
SPM is a kind of nickel chromium alloy, and it contains nickel. Without doing surface treatment like plating, it rarely could see change of color in the atmosphere.
As a general, our SPM frame is not done plating, which means nickel chromium is directly touched to the skin of user.
Recently, through the domestic and/or foreign exhibitions and web site, overseas clients are increasing who are interested in our SPM frames.
“Is it no problems if nickel alloy touches to the skin directly ?” We have received so many such questions, we requested Japan Spectacles And Popular Optics Inspection Institute (JSOI) for inspection.
The details of inspection are “Nickel Flow”, etc. based on European Spec (EN ISO 12870:2012). The result of inspection was “Nickel was not detected”, and our SPM frames was in conformity with the standard of “4.2.3.point – Nickel Flow” prescribed by European standard (EN ISO 12870:2012)
We could identified that our SPM frames are accommodate to the European standard, however, it does not mean that no one would not happened to metal allergy who is wearing our SPM frame.