Release of heavy metals from European and Asian porcelain dinnerware

Samples of porcelain dinnerware manufactured in five European and three Asian countries before the mid-1970s and subsequently brought into the US were subjected to acid leaching tests to investigate the release of heavy metals. Forty-six dishes decorated with decals or hand painted designs applied over the glaze were examined. Included in the selection were dishes from major manufacturers of fine dinnerware (Haviland Limoges, Rosenthal, Noritake) as well as samples from lesser-known or unidentified factories. During 24-h tests with 4% acetic acid, half of the samples (23 dishes) released lead in concentrations exceeding the US Food and Drug Administration (FDA) allowable maximum of 3.0 micrograms/ml and another 17 dishes released lead in concentrations ranging from 0.1 to 2.9 micrograms/ml. Five dishes released cadmium, but only one value exceeded the FDA limit of 0.5 microgram/ml. Zinc, cobalt, copper and chromium were also released by some of the dishes. None of the acetic acid solutions contained measurable concentrations of nickel although this metal, as well as those named above, could be extracted from some samples with 6 M nitric acid. The FDA has not established dinnerware extraction limits for any metals except lead and cadmium. All overglaze-decorated dishes imported into the US before the mid-1970s should be tested for lead release before they are used in the preparation, serving, or storage of food.