Manufacturers of eyewear for the European market now have a final technical reference to measure the risk of nickel release on the skin. CEN, the agency of the European Union that defines safety standards for goods circulating within the European Union, has designated a specific simulation method, based on corrosion, to track down the amount of nickel released from the metallic parts of the eyewear frames.
Developed with the help if Italy's Certottica, a new European nickel standard, EN 12472:2005, has been issued by CEN. By June of this year the new norm will replace both the initial norm issued in 1998 and an experimental one introduced in 2001.
The method allows to test whether the prototype frames release a dangerous quantity of nickel onto the skin after two years of normal use. Test samples are exposed for two hours to a temperature of 50C in an environment containing lactic acid and sodium chloride. They are then placed for a further five hours in a rotating recipient containing wood shavings and an abrasive paste with 48 percent silicon oxide. The new process is less harsh than the previous one, which was introduced in 1998. That method apparently generated higher levels of corrosion on the frames than those that could be expected after two years of normal use.