Printing inks in foods: Health assessment not possible owing to lack of data
The detection of the chemical isopropyl thioxanthone (ITX) in beverage cartons has triggered a discussion about the health safety of printing inks. Well in excess of 1,000 substances are used to print food packaging. Whether and, if so, the extent to which they can migrate to the food depends on the composition of the printing ink, the food and the packaging material. The problem: unlike many other substances that come into contact with food, printing inks are not regulated by law on the European level. For most of them no data are available which would permit a health assessment. This is the conclusion of an extraordinary meeting of the Plastics Committee of the Federal Institute for Risk Assessment which was held in Berlin at the end of the year with representatives of the printing ink industry.
The occurrence of a chemical in a food does not in itself constitute a risk to health. It is the harmfulness of the substance and the degree to which the consumer comes into contact with the substance that determines the scale of possible damage and the probability that it will occur. Residues of printing inks in foods may, therefore, be safe but they may equally constitute a serious risk to health. Given the lack of data, a health assessment is frequently not possible at the present time. As the manufacturers bear responsibility for the safety of their products, they should do everything in their power to prevent the migration of substances of this kind to foods and put together the data needed for a health assessment.
In contrast to numerous other substances in printing inks, toxicological data are available for the photo initiator ITX. However, they limit themselves to ruling out a mutagenic effect of the substance. They are not sufficient for an assessment of the levels of more than 50 microgram per kilogram detected in foods. Hence, what applies to other, as yet unassessed substances also applies to ITX: No statement can be made on the health risk. The high level of residues in some cases is not acceptable from the angle of risk assessment.
Talks between the Plastics Committee and representatives of the printing ink industry at BfR revealed that no technology is currently available to prevent the migration of substances from printing inks to food through a set-off effect or because of penetration of the packaging material. Nor is this situation likely to change in the short term. The printing ink industry favours its own guidelines for ensuring compliance with food law requirements. According to them, very risky substances are to be excluded from use and toxicological data are to be provided for other substances. BfR and the Plastics Committee are of the opinion that the envisaged deadlines are unacceptable. Depending on the level of the expected migration of the substance to food, industry only wishes to submit the data - in particular the data needed to clarify a possible mutagenic effect - between 2010 and 2015. This would mean that both the health assessment and checking of compliance with food law provisions would not be possible for a long time.
Further information on this subject can be accessed in german on the BfR homepage (www.bfr.bund.de) under “Bedarfsgegenstände”/Materialien im Kontakt mit Lebensmitteln.