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<p>The objectives set in this project were to:</p>
<ul>
<li>Further develop the technology produced in a previously funded Agency project (A03010/11/12).</li>
<li>To develop a test procedure for visible set off.</li>
<li>Develop suitable (non-dietary) exposure techniques and analytical methods to enable identification and quantification of ink/varnish components; in collaboration with industry produce reels of packaged printing with inks/varnishes of known composition and quantify the extent of set off.</li>
<li>Measure the extent of migration of selected components into food; and use the results of the above to develop a rapid screening method for set off.</li>
</ul>
<p>Background: Set off is defined as: ‘the unintentional transfer of substances used in printing inks from the printed (outer) surface of materials and articles intended for food packaging to the inner food contact surface.</p>
<p>As a result of the finding of 2-Isopropylthioxanthone (ITX) in drinks packaged in multi-layer cartons, most likely as a result of set off, ink suppliers are now introducing polymeric photoinitiators (used in printing inks to speed up the drying process of the ink using ultra violet light) and synergists (which take part in the reaction involving the photoinitiator) as partial or complete replacements for monomeric photoinitiators and synergists. There is very little published data on the extent of transfer of these new compounds to food contact surfaces via set off and their subsequent migration into food.</p>
<p>The aim of this project was firstly to further develop screening test procedures capable of measuring the extent of visible set off (which can be seen by the naked eye) of these replacements and other ink components to the food contact surface of packaging. Secondly exposure techniques and analytical methods to quantify individual ink components on the food contact surface of packaging were developed to allow the measurement of non-visible set off. Finally the migration of ink components was measured in a variety of foodstuffs from specially prepared test films. The project will enable laboratories to identify printing ink components on unused food packaging, estimate worst case migration and thereby assist in the prevention of packaging transferring components to foods at undesirable levels. </p>