Packaging protects the food from environmental impacts be it microorganisms or oxygen, but in itself contributes to chemical migration from the packaging material into the food.
This is nothing new and numerous concerns have been raised in the past about specific chemical components that come in contact with food.
Harmful chemical effects
Now, in a commentary published in the Journal of Epidemiology and Community Health , environmental scientists warn of potential harmful effects to human health from some of over 4000 synthetic chemicals used in the packaging, storage and processing of food not currently explored.
Despite the fact that most of these chemicals are regulated, the authors are concerned that consumers are chronically exposed to low levels of these substances throughout their lives.
“Whereas the science for some of these substances is being debated and policy makers struggle to satisfy the needs of stakeholders, consumers remain exposed to these chemicals daily, mostly unknowingly,” said the authors.
They claim that current safety testing is not adequately covering endocrine-disrupting effects that may lead to adverse health effects later in life.
Formaldehyde is widely present in plastic bottles used for fizzy drinks and melamine tableware, said the paper.
They also raise the issue of interaction between different chemicals that have not yet been studied.
This is a huge challenge for toxicologists and their current mathematical models used to calculate safe use.
The potential for a non-monotonic dose-response to induce endocrine-disrupting effects at low doses would be a nightmare scenario to test for. Of course the consequences if such an effect exists could be huge.
Time to respond
In a response, Breast Cancer UK said: "[It] fully shares the concerns raised that some of the chemicals used in food packaging could be adversely affecting our health, especially at key stages of development.
"The warning that our dietary exposure to certain chemicals is not even being considered in toxicology analysis is utterly unacceptable. We cannot begin to understand why diseases, such as breast cancer, are on the rise until we address this issue," they concluded.
Philip Law, the British Plastic Federation's director general designate, said plastics used in food packaging are subject to a whole battery of EU and national regulations.
"Developments in plastic packaging and indeed other forms of packaging have been responsible for vast improvements in the food hygiene over the last 50 years.
"We are at a far cry from the days when flies had to be swatted away from exposed butter packs in corner shops. It was not uncommon before the days of durable and sealable packaging for rotting food, improperly packed, to cause worrying levels of fatality."
Dr Ian Musgrave, senior lecturer in the faculty of medicine at the University of Adelaide, said formaldehyde is present in many foods naturally.
"To consume as much formaldehyde as is present in a 100g apple, you would need to drink at least 20 litres of mineral water that had been stored in polyethylene terephthalate (PET) bottles.
"Obviously the concern about formaldehyde from food packaging is significantly overrated, unless we are willing to place 'potential cancer hazard' stickers on fresh fruit and vegetables."
So where to start?
The authors of the commentary propose to integrate knowledge about the chemicals in food contact materials and their migration into food with epidemiological studies. But epidemiological studies of consumer food patterns are fraught with problems.
Common use of one-time food frequency questionnaires to capture long-term food consumption is inappropriate and will not be able to capture accurate food packaging information.
The authors admit that establishing potential cause and effect as a result of lifelong and largely invisible exposure will be difficult.
But still argue that some sort of population-based assessment and biomonitoring are urgently needed to tease out any potential links between food contact chemicals and chronic conditions like cancer, obesity, diabetes, neurological and inflammatory disorders.
“Since most foods are packaged, and the entire population is likely to be exposed, it is of utmost importance that gaps in knowledge are reliably and rapidly filled” they urge.
Retired professor Stefan Fabiansson is a public health veterinarian.
He has experience in working with meat quality issues from Sweden and Australia.
From there he moved on to cover public health issues, most recently at the European Food Safety Authority in Parma, Italy.
After his retirement he is sharing in his experience at focusonfoodsafety.wordpress.com