Migration of 18 trace elements from ceramic food contact material: Influence of pigment, pH, nature of acid and temperature

The effect of pH, nature of acid and temperature on trace element migration from ceramic ware treated with 18 commercially available glazes was studied. Besides of the well-studied lead and cadmium, migration of other toxic and non toxic elements such as aluminum, boron, barium, cobalt, chrome, copper, iron, lithium, magnesium, manganese, nickel, antimony, tin, strontium, titanium, vanadium, zinc and zirconium was investigated in order to evaluate their potential health hazards. Trace element concentrations were determined with Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). This study suggests that there is indeed a health risk concerning the possible migration of other elements than lead and cadmium. At low pH (2 < pH < 3), the nature of the acid plays an important role. Citric and malic acid seem to be more aggressive to the glaze than acetic acid except for aluminum, barium, chromium, iron and magnesium. The migration kinetics between pH 2 and 3 in acetic acid of these exceptions also are more exponential while the other elements display a decreasing linear gradient. In ceramics used for this study (fired at 900 °C), a linear relationship between the migration and the temperature was observed.

► The migration of other elements apart of lead and cadmium can also pose a health risk. ► The nature of the acid makes a great difference in leaching at low pH; not all elements respond equal to the same simulant. ► In the interval pH 2-3, the link with the migration values is nearly linear. ► Migration increases rather linear with temperature for ceramics with a firing temperature of 900 °C. ► Values measured after 2 h migration at elevated temperature rarely exceed these of 24 h at ambient temperature.