Is decorative chrome exempt from End of Life Vehicle Directives’ restrictions on hexavalent chrome/chromium? What is the chemical makeup of decorative chrome electroplating (on zinc die castings)? Is it free from hexavalent chromium? Can you provide any contacts/experts on this subject that I could talk to? Any additional information, explanation, suggestions, comments and recommendations will be greatly appreciated. Thanks in advance for your help. J.K.
We do not claim to be experts on the European Union’s ELV (End of Life Vehicle) Directives, but, since you asked, it is our understanding that the ELV Directive applies only to hexavalent chrome (<2 grams per vehicle ) and does NOT apply to chrome metal (Cr+0) and trivalent chrome (Cr+3). Hexavalent chrome (Cr+6) is the most easily released and the most toxic form of chrome; hexavalent chrome is about 1,000 times more toxic than trivalent (Cr+3) chrome.
Whether a decorative chrome bath is hexavalent or trivalent, it deposits chrome metal onto the surface of the substrate metal. For further information, there is an excellent section on Chromium Plating by Nabil Zaki in Product Finishing’s Directory and Technology Guide. This article is available online at www.pfonline.com/pfd0310.html.
An article on the ELVD appeared in Products Finishing in the May 2003 issue. You can find it at PF Online at www.pfonline.com/articles/050304.html.
We suggest you work with your plating chemical suppliers if you desire more detailed information, since they are on the front lines concerning this issue. Also, you can turn your web search engine to “ELV chromium”; I did and received a number of good hits.