Scoping investigations on the release of metals from the rim area of decorated articles (in support of the revision of Ceramic Directive 84/500/EEC)

Abstract

In the present work, the release of metals from 14 samples (9 industrial samples, 2 ad-hoc manufactured ceramic cups and 3 ad-hoc manufactured glasses) was investigated in order to provide underpinning data on migration of metals under different conditions from different samples. The rim area was tested using 2 different approaches (wine and a wine-simulating acidic liquid, i.e 4% aqueous acetic acid). The test using the simulant acetic acid 4% (AA4%) was further investigated using two different protocols (with and without the use of paraffin wax). The release of metals from glass samples were also studied into white wine as benchmark food. All the samples tested in this study released Pb. It was also possible to detect limited release of Cd and other metals from the rim area of decorated articles. It was observed that the release of Pb, Cd and other metals generally decreased in successive migrations. Highly decorated articles with very bright colours led to a greater release of metals. The release of elements from test articles into white wine was always lower than that into acidic simulants. The testing using citric acid at higher temperature and shorter time was not significantly more severe than that using acetic acid 4% and depended on the metals considered and potential damage of the heterogeneous decoration of the articles during the exposure. Overglaze decorated samples were more sensitive to exposure to food simulants and released metals to a greater extent than test articles with underglaze decorations. The use of melted paraffin wax on the non-rim area may gave lower migration of metals into food simulants and thus might be more realistic, but might not be necessarily relevant when considering the standard deviation of the results..