Framing the debate.
In her interesting and wide-ranging CET article (OT February 14, 2014, p51-54), Sally Bates suggests that nickel-containing spectacle frames commonly produce a dermatological reaction. As chairman of the British Standards Institution (BSI) committee responsible for spectacle frames, I would be very interested in the frequency of this problem. The European Nickel Directive came into effect in 2000; this regulates the amount of nickel that can be released through a protective coating from a nickel-containing article.
This requirement is now incorporated in the REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulation. The residual amount allowed should be low enough not to irritate anyone unless he/she is exceptionally sensitive to nickel. Manufacturers have to test samples of all metal spectacle frames for nickel release; the process is described in BS EN ISO 12870 Spectacle frames - requirements and test methods, which, in turn, refers to two standards that describe tests originally developed by the jewellery industry. The first simulating two years wear and corrosion, the second measuring the nickel release.
A European standardisation committee has been working very hard for the last four years, and a technical specification detailing two new methods for testing spectacle frames and sunglasses for nickel release will be published later this year.
The majority of plated spectacle frames are given an organic coating over the plating to protect the plating and help control any release from the substrate alloy. For the large majority of patients, the coatings are sufficient to protect the skin for the expected two-year life of the spectacles. My feeling is that metal frames are better from this point of view than those predating the Nickel Directive. Coating with clear nail varnish seems to be helpful as a short-term remedy, but recoating frames with lacquer is not normally done. I agree that wearers who are more sensitive to nickel should choose a frame made from ahypoallergenic material.
Ronald Rabbetts, chairman of the BSI committee responsible for spectacle frames, optometrist, Portsmouth