Chemist calls for rigorous investigation of leached compounds

Mark Peplow/Budapest, Hungary

A leading analytical chemist has claimed that widespread contamination of food by packaging materials is being ignored by government, scientists, and the food industry.

Koni Grob, scientific head of the Official Food Control Authority of the canton of Zurich, Switzerland, speaking here at the first European Chemistry Congress in Budapest, called for better oversight of chemical leaching from plastic packaging.

European legislation states that no more than 60mg of packaging materials should leach into each kilogram of food, explained Grob. But this limit is routinely breached, according to his team’s extensive research.

Grob said that oily foods in jars which have a PVC lining on their lids are particularly susceptible to leaching plasticiser compounds, such as epoxidised soy bean oil (ESBO). In a 2004 survey of ESBO leaching, Grob found that only two out of 86 food samples fell below the legal limit of 60mg/kg of leached material. A more extensive survey the following year showed similar results. 

Based on well-established toxicity tests, ESBO itself does not pose a safety issue, said Michele Suman, an analytical scientist for Italian food manufacturer Barilla. But it does prove that the migration of chemicals from food packaging is unacceptably high, and must be dealt with, he added. ’It’s important - there is a real problem,’ said Suman.

Grob insists he is not trying to start a food scare. Most of the leached compounds found in his analyses have not been identified, so there is no way to tell for sure whether they pose any risks to human health. But he believes it would be a serious mistake to simply ignore them. 

Although the problem has been known about for more than a decade, Grob said that food quality analysts simply aren’t looking for these compounds, focussing their attention instead on more stringently regulated compounds, such as pesticide residues. ’It’s a scandalous situation,’ he said. ’By far the most predominant contaminant is from food packaging.’

Grob accepts that overnight change is impossible. ’If you actually enforced [the legal limit for leaching], packaging would become impossible,’ he conceded. Instead, governments should work with producers to develop better analytical techniques, and a thorough investigative programme should be instituted across the EU. Alternatives to current packaging materials should also be found, he suggested.

But Suman warns there are currently no alternatives to PVC that will ensure microbiological safety. It is important to balance the tangible risks of food becoming contaminated by bacteria with the unknown risks of leached compounds, he said. 

Manufacturers are actively trying to find alternative sealants, said Suman, adding that better harmonisation between EU members states would help. For example, some nations allow certain packaging to be used for food that may leach phthalates, while in other places that packaging is banned, he explained. Yet the food industry exports across Europe, and coherent legislation would help companies stick to agreed standards.

Suman argued that since food manufacturers usually buy their packaging from other companies, there must be a joint effort with suppliers to tackle leaching. ’We want to face the problem together,’ he said.