Lead (Pb), a metal harmful to health, was found to be leached from ceramic kitchenware into a 5% acetic acid solution when the solution was held in the kitchenware for 90 min. This leaching of Pb was higher from dark-colored ceramic kitchenware such as green and brown than from light-colored ware. Pb was also observed to be leached when the ware containing vinegar samples or organic acids was heated for 1 min in a microwave oven. Acetic acid and oxalic acid, among the organic acids tested, were the most prominent for leaching out of Pb. Contamination of foods by Pb might therefore occur when acidic foods in ceramic kitchenware are heated in a microwave oven.
