One hundred and eleven ceramic ware products will be purchased in duplicate and the standard migration test with 4% acetic acid applied. The acidic extracts will be subjected to multi-element analysis by inductively coupled plasma-mass spectrometry to measure the migration of metals. The elements migrating at relatively high levels (by comparison with 50 times the median value) will be identified and these elements selected for analysis in subsequent investigations. Those products showing higher levels of metal ions leaching into the acetic acid solution will be selected for further studies. Additional specimens will be purchased so that in total four test specimens of each article type were exposed to the 4% acetic acid.
Ceramic ware products are repeat use articles and the migration of the selected elements into a fresh portion 4% acetic acid will be determined to establish the effect of repeat use on the exposure. Also migration into acidic foods will be determined and the effects of the worst foreseeable conditions of use (e.g. marinating, baking, microwaving, dishwashing, scouring and thermal shock; any of which may result in cracking and crazing of glaze) investigated.
A wide range of glazed ceramic ware products is commercially available today from countries within the EC and as imports from the rest of the world. The diversity of these products, in terms of their colours and designs, is vast. The clays, and particularly the coloured glazes used in the manufacture of this type of ware, contain a variety of metals. Metals used in the glazes include cobalt for blue colours, chromium for green, cadmium, selenium and sulphur for red/yellow/orange, copper, magnesium, antimony and vanadium to give stability or depth to a colour and calcium and lead to adjust the tone of the colour. Little information is available with regard to the potential for migration of these metals when ceramic ware products are used in contact with food and drink.
Current UK legislation specifies limits for cadmium and lead migration from ceramics into foods, based upon the use of 4% acetic acid as a food simulant.
The aims of this project are to:
Establish compliance with current legislation for the migration of lead and cadmium into the simulant 4% acetic acid (Directive 84/500/EEC) from a range of ceramic articles
Identify which other elements migrate into this simulant
Establish the validity of the current method of test by comparison of the results obtained using the simulant with those obtained for migration into foods under 'normal' and 'worst foreseeable' conditions of use.
<p>Find more about this project and other FSA food safety-related projects at the <a href="http://www.food.gov.uk/science/research/" target="_blank">Food Standards Agency Research webpage</a>.