Every scrap of processed food we eat has to be packed. Packaging protects food on its journey from the processing plant to shops and supermarkets, and to our homes. You may think you don’t eat processed foods, but in reality you probably eat them every day.
Whether it’s your lunchtime supermarket sushi, sandwich or salad, that fruit smoothie or slice of coffee-shop sponge cake, perhaps the salami you serve as hors d’oeuvres, or the carton of soup you warm up for a quick supper … these are all processed foods that, while regarded as relatively “healthy”, cohabit intimately with packaging chemicals for most of their lives.
Inside these packages, a number of polymer plastics hold precooked ingredients in their sticky embrace, all the while exchanging body fluids. Prawn mayonnaise sandwiches and peking duck wraps sit in the supermarket and takeaway shop chiller for 48 hours, oozing their oily innards on to the plastic and cardboard carton that has absorbed printing ink and is probably laminated with an ultra-fine plastic film. Tinned food languishes for years inside cans lacquered with epoxy resins — better known for being used in glue — or plastic coatings.
Even raw and more minimally processed foods get up close and personal with a range of advanced packaging materials. Supermarket meat is displayed on a plastic tray on a discreet blood-absorbing mat. Cheeses, even those with a wrapper of waxed paper to create the mood of an artisan cheesemonger’s, are often clad in tight-fitting plastic underwear. Most people won’t choose olive oil in a glass bottle, opting for the cheaper plastic container.
Children go to school with a plastic mini-pot of fromage frais. They drink juice through a plastic straw from a cardboard container coated with a plastic polymer and lined with metal foil. Raspberries are presented like royalty in a crystal-clear plastic container, under a layer of “breathable” film, on an absorbent crimson “bubble pad” that disguises any leaking juice; such pads can be supplied to packers pretreated with shelf-life extending fungicides.
The insides of the brown cardboard takeaway boxes used by food pop-ups and stalls at outdoor events are coated with wax, usually petroleum based.
The range of packaging materials and substances available to food manufacturers is elaborate and futuristic, with innovative concepts constantly coming on to the market. Many forms of plastic packaging, used for products such as ready-grated cheese, are often treated with a microscopic layer of chemicals, such as alkyl mono- and disulfonic acids, aluminium borate and N,N-bis (2-hydroxyethyl) dodecanamide.
They provide an “anti-fog” effect by stopping a build-up of moisture in the container, or act as “antistatics”, performing a non-stick function that allows foods such as honey and chocolate sauce to slip more easily from the pack. If you have ever felt cheated when those last remnants of ketchup stuck stubbornly at the bottom of the container, you might be receptive to cutting-edge LiquiGlide, although you are unlikely to know of its presence because packaging substances are not listed on food labels.
Reportedly, LiquiGlide was invented for coating car windshields and aeroplane wings, but it has been reformulated to line glass, plastic and metal food packaging. When applied to the inside of a bottle, the walls are so lubricated that condiments that would normally stick to the inside almost fall out. Mayonnaise dispensers treated with it hit the shelves this year.
One of the latest films, designed to pack cooked meats, cheese, milk, condiments and salad dressings, is composed of no fewer than seven microscopically thin plastic layers, and is described thus: “A multilayer plastic film comprising polyethylene outer layers with inner layers of additional polyethylene adjacent to tie layers of adhesive bonded to a blended polyamide and polyvinyl alcohol core.”
Shall I run that by you once again? Unless you are an expert in polymer chemistry, it may not mean much. Suffice to say, this film keeps out air and moisture, yet still looks attractive on the shelf. As you can see, food packaging technology is tirelessly revolutionary with up-to-the-minute, game-changing options becoming available all the time.
Does this matter? According to the UK’s Food Standards Agency: “Consumers should not be concerned by the presence of chemicals in food contact materials if they are used within any limits or restrictions set for their use.”
So that’s all right, then … or is it? The Food Packaging Forum, a not-for-profit, independent foundation that examines the science around packaging, thinks differently. It constantly reviews scientific data on which chemicals migrate from packaging into food and beverages, under which conditions and at what levels.
It recently warned that 175 chemicals found in food packaging are defined by international classification bodies as “chemicals of concern”, because they had been linked to cancer, reduced fertility, genital malformations and hormone disruption.
The list of chemicals that have long been linked to health concerns, yet are routinely and legally used to pack what we eat and drink, is an eye-opener. To give you a flavour, it includes formaldehyde, benzene, propylparaben, ammonia, toluene, perchloroethylene, carbon monoxide, asbestos, and chlorinated paraffin.
How can this be permitted? Food-contact materials have been in the frame as a possibly important source of chronic exposure to chemicals and, in a horrible synergy, their toxicity can be increased in the presence of other chemicals with the same mode of action.
Packaging manufacturers must legally guarantee that their products “do not transfer their constituents to food in quantities which could endanger human health”, so who would expect chemicals known to be toxic to be used intentionally in food-contact materials? After all, many chemicals used to make food packaging match the criteria for “substances of very high concern” set by the European Union’s chemical authorisation body.
Under European rules, chemicals with highly toxic properties must be registered and approved for use, but the guidelines do not cover food packaging. So, perversely, although these rules extend to chemicals used in making toys, paints, textiles and medical equipment, they do not cover food-contact materials, even though many people are exposed to them every day of their lives.
Why aren’t packaging chemicals more controlled? Such brinkmanship is hard-wired into the industrial food system. It operates on the assumption that potential toxins have no harmful effects, provided the concentration is low enough. So nothing is done, although many researchers suspect that some chemicals have unexpected and potent effects even at low doses.
Bisphenol A, used to line cans and make plastic containers, is a case in point. After one of the largest reviews of independent, non-industry research literature on it, an expert panel warned: “Recent trends in human diseases relate to adverse effects observed in experimental animals exposed to low doses. Specific examples include: the increase in prostate and breast cancer, urogenital abnormalities in male babies, a decline in semen quality in men, early onset of puberty in girls, metabolic disorders including insulin-resistant (type 2) diabetes and obesity, and neurobehavioural problems such as attention deficit hyperactivity disorder.”
A sobering assessment but, despite such warnings, the scientific “consensus” needed to get regulators to act is not deemed to have been established, something not entirely unconnected, perhaps, with the packaging industry’s determination to quash any suggestion that its products might possibly cause harm. Yet, however much the industry counters its critics, the world is not wholly persuaded.
Public concern has resulted in bisphenol A being banned in packaging and reusable food containers, such as “sippy cups”, intended for children under three, in Canada, the EU and the US. Several cancer charities advise people to avoid bisphenol A. Breast Cancer UK has called for a ban. There are parallels with the long war over proving the harm done by tobacco. Independent scientists were ringing alarm bells — and regulators and consumers were acting on their advice — long before the damage was “proved” conclusively.
Phthalates — plasticisers added to films to keep them soft — have also been shown to migrate into food, which is worrying because increased levels of phthalates are associated with obesity and reduced masculinisation in new-born boys. Yet phthalates are all around us. In 2012 the Food Standards Agency reported that 31 per cent of everyday foods tested contained phthalates above the legal level, with the highest levels in bread.
Controversy over bisphenol A and phthalates has been aired for decades but the same cannot be said for nanoparticles, an emerging technology. Too minute to be seen with a microscope, they are derived from materials such as clay, silver, titanium, silica and zinc oxide. They perform certain “smart” functions: extending the shelf-life of food by decreasing the permeability of plastics; acting as antibacterial coatings; or making packaging lighter and stronger. Researchers recently found that aluminium and silicon nanoparticles migrated from plastic bottles into an acidic medium — the kind you find in fizzy drinks and juices.
Should we be worried? The potential problem with nanoparticles is their minuteness. They are about one ten thousandth the width of a human hair, making them more reactive and more bioactive than larger particles of the same substance. This means they can end up in places that larger particles would not — our cells, tissues and organs, where they can accumulate to ill effect.
Nano-scale zinc oxide, for example, has been found to cause lesions in the liver, pancreas, heart and stomach in laboratory animals. Other research suggests that nanoparticles of titanium dioxide can damage DNA and disrupt cell function. One emerging theory is that nanoparticles may be a factor in the growing prevalence of irritable bowel syndrome and Crohn’s disease.
Five hundred nano-packaging products are now estimated to be in use and packaging is just the advanced guard for this novel technology. Nanotech additives are already out in force on US shelves. Nano-sized titanium dioxide, for example, is turning up in coffee creamer, cookies, cream cheese, turkey gravy, lemonade and chocolate. Fresh fruit and vegetables can also be coated with a thin, wax-like coating, containing nanoparticles, to extend shelf life.
Could nanotech additives be in the UK food chain? No one really knows and food manufacturers have no legal obligation to tell us of their presence.
Of course, if you cook mainly from scratch at home, you limit your exposure to packaging chemicals. In the domestic setting we tend to chop on wood, cook with steel utensils and serve in ceramic and glass — materials with a long history of safe use.
Yet whether we are talking of imperceptible nanoparticles or the well-stocked cabinet of chemicals that performs sterling service in the production of food and drink packaging, an obvious question arises: how many minute doses of poisons can we be exposed to before our bodies abandon resistance and get ill? Is it not possible that toxins, like playground bullies, gang up to form an undesirable cocktail effect?
We must be open-minded enough to consider the real possibility that, by activating, blocking, hijacking or otherwise messing with the normal functions of our bodies, engineered chemicals are contributing to a wide range of health problems, including obesity, diabetes, cancer, cardiovascular disease, infertility and other disorders of sexual development.
If we take this proposition seriously, reducing our exposure to such substances by minimising the amount of packaged, processed food and drink we consume is surely an obvious place to start.