A "highly toxic" chemical in the glue on supermarket labels can seep through packaging and contaminate food, a study has shown.
The chemical, which is in the highest toxicity category because it poses a "particularly severe risk to health", is found in high levels on some of the sticky labels placed on packages of fresh meat, vegetables, tubs of sauce and other foodstuffs.
Strict EU safety regulations govern which materials can come into direct contact with food, but there are no rules about the chemicals in adhesives used to fix labels to the packaging.
A study published today by the Royal Society of Chemistry shows that four toxic compounds in commonly-used glues on sticky labels can seep all the way through paper and plastic packaging and contaminate the food inside.
One such adhesive is in the "highly toxic" class along with other poisonous chemicals such as mercury, asbestos and hydrochloric acid. Highly toxic chemicals can cause organ failure and even death in high doses.
The researchers, from the University of Zaragoza, Spain, studied four different acrylic adhesives commonly used on food labels.
They examined in detail 11 compounds found in the adhesives, ten of which had low toxicity while the remaining compound – 2,4,7,9-tetramethyldec-5-yne-4,7-diol – belonged to the highest risk category.
The team placed the adhesive on to a layer of polymer or paper covering the food stimulant Tenax to measure whether it was capable of penetrating the packaging.
Valérie Guillard, an expert in food technology at the University of Montpellier, France, said: “This work brings significant breakthroughs in the study of compliance with regulations of food contact materials.” She believes the research shows that “migration of adhesive compounds is possible and at a level that could raise safety concerns”.
The Food Standards Agency said the findings highlighted "a potential area of further research" as part of its "horizon-scanning for developing risks".
But a spokeswoman said: "Our own research has found that although several chemical substances are present in adhesives, the potential for them to migrate into food is very low."
The results are published in the latest edition of the RSC’s Journal of Materials Chemistr