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The approach taken has included desk research, discussions with resin suppliers, and visits to and contacts with the food industry. The main part of the research has been a detailed analytical testing programme on six types of ion exchange resin, representative of resin types used commercially. Extractable ionic and organic substances have been examined using combined liquid chromatography/mass spectrometry (LC-MS) and gas chromatography/mass spectrometry (GC-MS).
Ion-exchange resins are used to remove or isolate specific ions or ionisable species from water and food products during processing stages in their manufacture. To date, there is no EU harmonised legislation for such resins as food contact materials. However, Annexe 1 to the new Framework Regulation for food-contact materials (1935/2004/EC) includes ion-exchange resins within a list of groups of materials and articles that may be covered by specific measures.
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In addition, the Council of Europe has issued a resolution on ion-exchange resins (AP 97/1). This is not a legally binding document but members of the Partial Agreement in the Social and Public Health Field, such as the United Kingdom, are expected to take note of such resolutions.
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Included in the resolution is an inventory list of substances used in the manufacture of ion-exchange resins and a migration limit of 1mg/litre total organic carbon in the 5th bed volume (water) rinse solution. In the USA, a list of ion-exchange resins authorised for food-contact use, together with some restrictions, is given in the FDA regulations (Title 21, Section 173.25).
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The aim of this project was to provide background information on the use of ion exchange resins and to determine possible migrants from such uses, with a view to informing future negotiations on possible EU legislation. <p>The objectives were to determine:
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the main types of ion-exchange resins currently used in contact with food
the major applications of ion-exchange resins used in contact with food
typical usage conditions
the nature of potential migrants from the resins
whether standard EU food simulants are suitable for migration testing or whether testing should be undertaken in more acidic or alkaline solution to reflect the use of the resins
whether regeneration introduces resin breakdown and potential migratory species
the effect of resin misuse on potential migrants
whether testing leachable substances in the 5th bed volume is adequate (as required by the Council of Europe Resolution on ion-exchange resins)
whether or not migrating species from ion-exchange resins can be detected in food
<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>.