Notes on a scandal

Do label adhesives migrate into food? To judge by the headlines in the popular press over the summer, you would certainly think so. ‘Toxic glue used in supermarket food packaging poses severe risk to health,’ screamed the headline in one leading UK tabloid. 

But products were not pulled from shelves and there has been no mass outbreak of adhesive related deaths. So what’s going on? 

In Europe, most food packaging and food contact materials are manufactured with some sort of adhesives. Like all components of food contact materials, adhesives have to be compliant to Article 3, of European Union (EU) Regulation 1935/2004 which states there should be ‘No transfer of substances on or into the food in amounts which could endanger human health’. 

But there is no specific regulation in EU or member states about how to implement this requirement when it comes to adhesives – a completely different situation to plastics, for example, where component migration limits are tightly defined. 

It was with this in mind that the MIGRESIVES project, a 3 million euro study, was undertaken. The basis for the project, part commissioned by the EU, was to develop pragmatic, science based tools to support future EU regulations for adhesives used in food packaging. 

The project team produced mathematical modelling software to predict migration, and will launch practical testing tools later this year. 

In May 2010, a paper seeking to validate the model against experiments on real-world adhesives – including adhesives on PS labels – was released by researchers at the University of Zaragoza (UNIZAR) in Spain and published in the Royal Society of Chemistry’s Journal of Material Chemistry. 

Prof Dr Cristina Nerin, a scientist from UNIZAR who worked on the project, told L&L that the adhesives used in the study were supplied by commercial companies. But, critically, the tests used concentrations of adhesive far greater than those found in real world packaging and labeling applications. 

‘The acrylic adhesive under study is used for sticking the PP window of paper bags commonly used for bread. It is applied in dots and the total amount of adhesive in the package is very low,’ explained Professor Nerin. ‘However, in our research studies the total surface was covered by the adhesive, as it is required for diffusion and partition studies as well as for migration tests. When this value is referred to the usual amount in real life, the migration value is lower than the established limit, even taking into account the Crammer list values for class III (high toxic).’ 

In other words, there are no dangerous levels of migration from the small amounts of adhesive found in commercial packaging. It is only when the concentration of adhesive is scaled up for experimental purposes that potentially dangerous levels of contaminant are found to have migrated into the food. 

So how did this non-controversial finding become the headline about ‘Toxic glue in supermarkets’?

Distortion 

This part of the story begins with a press release sent to journalists by the Royal Society of Chemistry’s PR manager. Sensing a sensational news angle, the press release focused on the migration of this one compound through plastic - forgetting to mention that the chemicals would never appear in such high concentrations on consumer packaging.

‘Chemicals used in adhesives for food labels can seep through packaging and contaminate food, according to research published by the Royal Society of Chemistry,’ the press release began. ‘[A team of scientists] discovered that some chemicals can diffuse through the packaging and reach the food inside. One of those is considered highly toxic and found in high concentration in some adhesives.’ 

Uncritical journalists, not bothering to check their facts, then turned the ‘story’ into a full-blown scare. 

One major UK tabloid even added its own alarming ‘facts’, announcing that the UNIZAR scientists had discovered the chemical was ‘in the same toxicity as mercury, asbestos and hydrochloric acid’ and ‘can seep through [food packaging] and contaminate food’. 

It went on to incorrectly claim that ‘it [the chemical] has been found in high levels on some of the sticky labels attached to packages of fresh meat, vegetables and tubs of sauce’, as well as to declare it could pose a ‘particularly severe risk to health’ as highly toxic chemicals ‘can cause organ failure and even death in high doses’. 

It was a dismal display of lazy and misinformed journalism. It was also highly misleading and dangerous, considering this tabloid has a readership of over a million people in the UK and commands an even greater following on its website. 

The panic did not take long to set in. One reader posted a comment on the tabloid’s website stating that she was ‘sickened that these labels would give her cancer’, while at the same time a debate began to rage over the dangers of hydrochloric acid and what would happen if people began to consume it from their daily food intake.

The story began to spread rapidly. It was copied and pasted onto private and corporate blogs around the world. A Google search of the story’s headline pulled up close to 4000 results. Food consumer websites were quoting what the newspaper had published. 

Fighting back

Once such a band wagon starts rolling, it is extraordinarily difficult to stop it, as FEICA, the European Adhesive & Sealant Manufacturing Association, was to discover.

In June, FEICA put out a statement which called the reports in the UK press ‘inaccurate and misleading’, stating quite clearly: ‘The laboratory samples were made for scientific experiment only and were not representative of the concentration levels used in commercial adhesive.’ It was comprehensively ignored. 

When L&L confronted the Royal Society of Chemistry over its sensationalist presentation of the UNIZAR findings, a spokesperson put the blame firmly on journalists. ‘The media also receive a copy of the article in full at the same time as the media release so journalists can research their story as they see fit.’ The newspapers which ran the original scare stories declined to comment when approached by L&L. 

Meanwhile, the misleading stories about the ‘dangers’ posed by packaging and labeling adhesives continue to circulate and spread across the internet. 

This article was published in L&L issue 5, 2010