Leading food manufacturers are changing the packaging they use for products such as breakfast cereal, after researchers raised concern about possible health risks from recycled cardboard, it was reported today.
Researchers in Switzerland found that mineral oils in printing ink from recycled newspapers used in cardboard can get into foods such as cereal, pasta and rice - even passing through protective inner plastic bags.
Dr Koni Grob, of the Food Safety Laboratory in Zurich, said toxicologists had linked the oils to inflammation of internal organs and even cancer, though he stressed that individual meals would contain only a tiny dose of the chemicals.
The BBC reported that cereal firm Jordans has stopped using recycled cardboard while other manufacturers are taking action to reduce levels of mineral oils in packaging.
The Swiss researchers analysed a total of 119 products bought from German supermarkets last year and found that a large majority contained traces of mineral oils higher than the agreed level. Only those with thicker and more expensive inner lining bags appeared to escape contamination, which increased the longer products were on the shelves.
"Roughly 30 products from 119 were free of mineral oils, nearly all because of an inner barrier," said Dr Grob. "For the others, they all exceeded the limits and most exceeded it by 10 times.
"We calculated that before the end of their shelf life, they would probably exceed the limit 50 times on average and many would exceed it by several hundred times."
Studies on rats have highlighted the dangers to health of mineral oils, said Dr Grob, adding: "Toxicologists talk about two effects. One is the chronic inflammation of various internal organs and the other one is cancer."
But he added: "One meal has no real effect on health. It is a matter of long-term exposure."
And Swiss food safety authorities have concluded that consumers who eat a balanced and varied diet have no need to worry.
In a statement, Jordans told the BBC it had stopped using recycled card: "As an environmentally-conscious business, Jordans take the decision reluctantly, but felt it was sensible."
Meanwhile, Kellogg's said: "We are working with our suppliers on new packaging which allows us to meet our environmental commitments but will also contain significantly lower levels of mineral oil. We are also looking at alternative inner liners for our packs."
And Weetabix told the BBC: "Weetabix is actively engaged with its packaging suppliers to consider alternative recycled packaging that doesn't contain recycled newspapers. Our data... does indicate that none of our products pose a risk to consumer health."
Barbara Gallani, of the Food and Drink Federation, which represents Britain's food companies, said the Swiss study was "a good starting point for further investigations" - but not enough in itself to justify discontinuing the use of recycled card.
"Moving away from the use of recycled board in food packaging would be a very drastic measure that only needs to be taken if the issue is serious enough," she said.
"There are ways - and we are investigating those - to minimise migration and to select cardboard that contains lower levels of mineral oils."
Britain's Food Safety Agency is carrying out its own investigations into the presence of mineral oils in food packaging.
Terry Donohoe, head of the FSA's chemical safety division, said: "Should there be any evidence from our study - and we will carry out a risk assessment - we will take immediate action to protect the public."
Dr Grob warned consumers against panicking in the face of the research.
He added that a wholesale switch to using fresh fibres in packaging would be too costly in terms of the environment.
Manufacturers should instead explore introducing packaging which can act as a barrier against mineral oils, he said, or the option of depositing a barrier directly on to the paper board packaging.
He said research had shown that materials such as paper had no protective effect and packaging such as polyethylene and polypropylene had very little effect either. Aluminium foil was effective, he added.
"Our bodies already contain on average roughly around one gramme mineral oil - that is by far the largest contaminant we have in our body. For some people it is 10 grammes, which is a high value," he said.
"We are obviously accumulating mineral oil over a lifetime, what the baby gets through human milk is probably staying over a lifetime. For this reason, one month or less has no real effect, so there is no emergency, consumers should not make any rapid changes, we have to think about it," he said.
"The easy idea to change over to fresh fibres is not a viable solution because it would cost too many trees. We need better solutions such as introducing special barriers."
A Kellogg's spokesman said: "While experts tell us there's no immediate health concern, we are looking at our packaging.
"We are working with our suppliers on new packaging which allows us to meet our environmental commitments but will also contain significantly lower levels of mineral oil. We are also looking at alternative inner liners for our packets.
"Whilst there are strict regulations when it comes to the packaging of food, there is currently no direction from the UK Government about mineral oils.
"We will immediately follow any such guidance once it has been given."
He added that switching to virgin board would not solve the problem of mineral oil migration from other recycled packaging.
"Our understanding is that (switching to virgin board) would have a major environmental impact in a negative sense and still does not solve the problem, so obviously we are looking at alternatives," he said.
A Food Standards Agency (FSA) spokesman said: "The FSA is not aware of any firm evidence to suggest that there are food safety risks related to mineral oils in recycled food packaging.
"The research is interesting, but due to incomplete data the results have not demonstrated that mineral oils in food packaging represent a food safety risk.
"The FSA is currently gathering information on the extent of the presence of mineral oils in food packaging on the UK market.
"The agency is also specifically looking at recycled material to ensure that manufacturing processes successfully remove substances that could present a food safety concern from the finished packaging.
"Manufacturers are responsible for ensuring the food they produce is safe, and some have chosen to review their use of recycled packaging.
"The agency continues to review evidence in this area and will act to protect consumers if the evidence shows it is necessary to do so."
Ms Gallani, of the Food and Drink Federation, said: "We are aware of recent studies looking at the potential presence of mineral hydrocarbons in food from recycled cardboard used in food packaging.
"We understand that the information currently available is limited and we are working with the FSA, food manufacturers, retailers and the packaging supply chain to gather more information.
"The FSA has indicated that there is not a need for immediate action. It is carrying out a survey of food packaging materials including recycled cardboard and will report back in the summer.
"In the meantime, FDF has revised guidance for food manufacturers on recycled carton board in food packaging."
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