Scoping investigations on the release of metals from crystalware : in support of the revision of the Ceramic Directive 84/500/EEC

In the present work, the release from 15 samples of crystalware was investigated with respect to migration of metals in different conditions from different samples. Three test regimes were compared. The first one, currently in use for ceramic, foresees the use of acetic acid 4% as simulant and the test conditions are 22°C for 24 hours. This procedure was repeated three times to better represent the repeated use regime. Two alternative approaches: 1) citric acid 0.5% for 2 hours at 70ºC, three consecutives migrations and 2) pre-conditioning of the ceramic with acetic acid 10% during 5 hours followed by a single migration for 24h at 22°C with acetic acid 4% were investigated to shorten the time of analysis. The release of metals was also studied into white wine as benchmark food. For all samples included in the study a relevant release of Pb was observed. Only few other metals were found in leaching solutions: Zn, Sb, Ba and Ag. Both simulants presented higher migration respect to the white wine as a benchmark food. In general the release of metals seemed to be higher with citric acid than with the acetic acid in the first migration. Migration values obtained with pre conditioning step were above the third migration obtained with the conventional test with acetic acid.