Hexavalent chromium, Cr(VI), has traditionally been used as a pigment for paints and plastics, with both Chromium Yellow (PbCrO4) and Chromium Red (PbCrO4•Pb(OH)2) extensively applied in the U.S. and Europe. However, due to the adverse health effects associated with Cr(VI) and lead, these pigments and other hexavalent chromium compounds were largely banned for use in electronic products under the EU RoHS Directive (2006). But how can processors and their customers be assured these pigments no longer are in their products?
That is the question tackled by Joe Kuczynski and Sophia Lau, both of whom work for IBM at its facility in Rochester, MN. Kuczynski works at IBM's Material and Process Engineering Lab, while Lau is employed in the IBM Center of Excellence for WW Product Environmental Compliance. The two authored this article for readers of PlasticsToday and also offer insight into ongoing work that may help answer the question and work to keep illegal pigments out of plastic products.