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What are nanoparticles? We take a look at the health risks

What are nanoparticles? We take a look at the health risks

Credit: Daoudi Aissa

Something has been quietly slipping into food products. Tiny nanoparticles have been finding their way into a number of items on the supermarket shelves, unlabelled and subject to minimal regulation. A number of scientists and environment groups are calling for greater oversight and precaution.

In terms of its size, a nanoparticle is less than 100 nanometres (nm) in at least one dimension. To put this in perspective, a sheet of paper is about 100,000nm thick. Particles of such size can exhibit unusual behaviour more in common with the quantum realm, and are generally more reactive. Their tiny size alone represents a potential safety issue.

Nanofoods & their critics

Nanotechnology foods have some similarities to genetic modification of food. Both are novel technologies that were quietly introduced into the food supply without any fanfare and suffer from a lack of consumer enthusiasm that can extend to mistrust. In both cases, there is a tension between democratised low-tech food and the corporate world of high-tech.

Food manufacturers may add nanofoods to their products for reasons like extended shelf life, altered texture, enhanced nutritional qualities and changes in taste. Sometimes the nano-scale intensifies the properties of conventional ingredients, an example being nanosalt grains that have a greater surface area and consequently achieve the same taste effect with less salt intake. For mayonnaise, the fat content can be reduced through the use of fat-coated water droplets.

Particles of [nanosize] can exhibit unusual behaviour more in common with the quantum realm, and are generally more reactive.

Also on the horizon are weird “programmable” nanofoods that can be customised by the user to alter properties such as colour, flavour and nutrients.

In Australia, the Friends of the Earth (FOE) Emerging Technology Project tackles nanotechnology and the allied fields of genetic manipulation, synthetic biology and geoengineering. FOE is calling for public scrutiny of the environmental and social impacts of new technologies and, where implemented, for them to reflect the community’s broadest interest rather than corporate or military agendas.

Company policies

It is important to distinguish between engineered nanoparticles and naturally occurring nano-sized particles that already exist in foods such as milk, ground flour and burnt toast. Among conventionally produced supplies of a particular food ingredient, a small percentage may be made up of naturally occurring nanoparticles.

Following the GM consumer backlash, companies are understandably cautious about embracing nanotechnology. Yet with no major food company having a clear nano-free policy, the chances of consuming some nanofoods in a processed diet are high. If approaching food manufacturers, their responses might be inaccurate, perhaps unintentionally so; they are unlikely to know with any certainty whether they use nanofoods because ingredients can be supplied in nano form without being specified as such.

For concerned consumers, the easiest way to avoid nanoparticles is to buy certified organic. While nanoparticles are excluded from organic foods in Australia and the New Zealand AsureQuality certification, for BioGro in New Zealand and those imported from the US there is no nano-specific prohibition.

Otherwise, steer away from processed foods with numerous ingredients, especially E-number additives.

What is on the market?

At present, the number of potentially nano-scale food applications is limited, but there are some potential nanofoods and ingredients to look out for:

  • Nano titanium dioxide (some E171). This white colouring is used in sweets, coconut, yoghurt and powdered sugar.
  • Nano iron oxide (some E172), used as a red, black or yellow colour.
  • Nano-silica (silicon dioxide, some E551), used as an anti-caking agent in powdered foods such as coffee, salt and powdered sauce mixes.
  • Nano-hydroxyapatite, which is often used in baby formula as a calcium source.
  • Similarly, nano-calcite is another calcium source in baby formula.
  • BASF’s LycoVit is a synthetic form of the antioxidant lycopene, measuring less than 200nm, which puts it in a nano borderland region.

For some foods and nutritional supplements, “microencapsulation” in nanocapsules delivers nutrients in a time-release system where they can be absorbed by the small intestine.

In the Netherlands, Eatnano is a company that trumpets its values through its name. With more emphasis on the ideological agenda of nano-ising food than on making a buck, it uses microencapsulation technology in some ingredients and claims that its meals and shakes meet all of one’s nutritional needs.

Nanofoods confirmed in test results

Over the past few years, laboratory tests have confirmed that nanoparticles are widely used in certain types of processed foods.

Shareholder advocacy group As You Sow tested American chain Dunkin’ Donuts for nano titanium dioxide on their white-powdered donuts and obtained a positive result. A shareholder resolution to remove this ingredient received a remarkably high 19 per cent support from the voting capital, and later the company opted to eliminate this ingredient.

For concerned consumers, the easiest way to avoid nanoparticles is to buy certified organic.

Friends of the Earth in the US purchased six samples of baby formula, of which three were found to have uncomfortably needle-shaped hydroxyapatite nanoparticles. These were in the Gerber, Enfamil and Well Beginnings brands. The European Commission’s Scientific Committee on Consumer Safety has warned against the use of needle-type nano-hydroxyapatite in cosmetics.

In 2015, FOE Emerging Tech arranged for the testing of 14 Australian grocery items for nano titanium dioxide or nano silica, with all samples coming up positive. The full list of tests was:

  • Titanium dioxide: Allen’s Kool Mints; Duncan Hines Creamy Frosting; Eclipse Chewy Mints; M & Ms; Mentos Pure Fresh Gum; Praise Caesar dressing; Skittles Fruits; Woolworths Homebrand White Sauce; and Woolworths Homebrand Sour Straps.
  • Silica: Maggi Roast Meat Gravy; Moccona Cappucino Coffee sachets; Nestlé Coffee Mate Creamer; Nice ‘N’ Tasty Chicken Salt; and Old El Paso taco spice mix.

Food Standards Australia New Zealand (FSANZ) chief executive Steve McCutcheon stated in a Senate Estimates Hearing that about 15 per cent of both additives occur naturally in a nano form. In response, Jeremy Tager of Friends of the Earth pointed out that, if this figure were used as a threshold, then for 12 of the 14 products the concentration of nanoparticles exceeds what could be expected to occur naturally. In the tests, titanium dioxide nanoparticle concentration ranged from 10 to 50 per cent, compared to 100 per cent for silica.

Food contact packaging

Unlike jurisdictions such as the EU, US and Canada, for Australia and New Zealand no regulatory guidance is provided on the use of nanoparticles in food packaging. Examples include:

  • “Smart” packaging equipped with “nanosensors” that detect pathogens by changing colour. This doesn’t appear to be on the market yet.
  • McDonald’s in the US has been using a nano-sized adhesive in burger containers that has enabled the company to switch from petrochemicals to renewable starch.
  • In some American PET (recycling code 1) beer bottles, clay nanoparticles are used as a barrier to impede the escape of fizzy carbon dioxide. Companies include Miller (US) and Hite (South Korea).
  • Other nanoparticles found in some food plastics are titanium nitride, titanium dioxide, zinc sulfide and zinc oxide.

While most food packaging nanoparticles are considered to be held in a matrix and are therefore unlikely to be released, the same cannot be said for nanosilver. Possessing antibacterial properties, it’s designed to make contact with food and improve its keeping properties. At present, there appear to be very few foods on the market packaged with nanosilver. Food-contact products labelled “antibacterial” might be impregnated with nanosilver and, although Microban avoids it, the company uses risky triclosan instead.

Health risks

Among nanoparticles, some that are readily metabolised by the body are considered to be of low concern. On the other hand, metals and metal oxides such as titanium dioxide and nanosilver are potentially more detrimental to human health and have raised red flags.

At the higher-risk end, animal studies have discovered several issues, although not every one of them has been linked to each chemical:

  • Being absorbed by the intestine and entering the bloodstream
  • Entering cells
  • Interference with the defence behaviour of immune cells
  • Triggering and accelerating early stages of colorectal cancer
  • Damage to beneficial bacteria
  • DNA and chromosome damage
  • Migration to organs, where they can have toxic effects
  • Crossing the placenta and being taken up by the foetus
  • Inflammatory action in the body

With a lack of available safety data, a precautionary approach is being urged. FOE has called for all 14 of the tested products to be removed from sale until their safety has been proven.

Regulatory shortcomings

Globally, nanofoods could be described as regulated only in the EU and Switzerland, with other countries offering non-legally-binding guidance. Australia and New Zealand have a weak industry-friendly regulatory system that fails to evaluate nanofoods under a nano-specific framework.

FSANZ rejects that nanoparticles are liable to be riskier than their conventional counterparts by virtue of size, despite the opposite view having been expressed by the Australian Pesticides and Veterinary Medicines Authority, and the Royal Society in the UK. In general, FSANZ appears to be inferring safety from an absence of evidence of harm.

In 2011, the Blewett review into food labelling produced the Labelling Logic report that saw an urgent need for FSANZ to create a nanofood standard, including mandatory labelling. The response from the Forum on Food Regulation, made up of Australian and New Zealand health ministers, was to soft-pedal this as a priority.

In general, FSANZ appears to be inferring safety from an absence of evidence of harm.

Under the Australia/New Zealand regulatory system, businesses are required to apply to FSANZ before they use novel foods, which can easily be argued to extend to foods with engineered nanoparticles. As an exemption, FSANZ has privately advised at least one food company that nanoparticles likely to dissolve in fats and liquids are excluded.

Until recently, FSANZ used the fact that no company had applied for approval as a lack of evidence that nanoparticles were being used in Australia or New Zealand, and further as a justification not to test for them, conduct safety studies, or set up nano-specific regulation. When the 2015 FOE testing proved that nanoparticles were being used, the FSANZ response was to argue that they were naturally occurring outliers rather than deliberately engineered particles, although this conclusion was generally not supported by the concentrations encountered.

One of FOE’s demands is the call for a national register of nanomaterials and products containing these materials, and this is backed up Professor Thomas Faunce at the Australian National University.

A need for labelling

At present there are no labelling requirements for nanofoods or nano food packaging in Australia and New Zealand. With labelling representing freedom to decide whether to consume a controversial novel food, its absence conversely prevents a meaningful choice from being made. A poll carried out for Friends of the Earth Australia in 2008 found that only 15 per cent of respondents were actively interested in purchasing nanofoods. Additionally, there was 96 per cent support for safety testing and 92 per cent in favour of labelling.

Worldwide, only in the EU is labelling required for engineered nanoparticles. One critical issue is the percentage threshold for nano content, with the current EU figure being 50 per cent. This has been criticised as being too industry-friendly, as it would exempt most products containing nano ingredients. At the other end of the scale, the EU Scientific Committee on Emerging and Newly Identified Health Risks suggested a vastly lower threshold of 0.15 per cent, which was rejected.

Disappointingly, it appears that this labelling rule is being ignored, given that no product in the EU is known to be labelled. Likely causes are the onerous expense of regular tests coupled with a passive regulator. Over the past year, a French environment group has tested six products, five for nano titanium dioxide and one for nano silica. All results came out positive, with two ingredients at a 100 per cent nanoparticle concentration that should have triggered labelling. The group’s strategy is to continue with these tests every few months until it makes some headway with the French authorities.

Re-evaluating priorities

While large sums of money are spent on fiddling with food for rich consumers, in the form of nano-manipulation and other novel technologies, the same financial resources could be spent on feeding the world through ecological agriculture. However, these technologies are commonly supported by governments because they generate new value-added economic activity and dovetail into the fixation on growth.

In the light of low consumer interest and potential risks, Australia and New Zealand deserve a strong labelling regime for both nanofoods and other novel foods.


Martin Oliver

Martin Oliver writes for several Australian holistic publications including WellBeing on a range of topics, including environmental issues. He believes that the world is going through a major transition and he is keen to help birth a peaceful, cooperative and sustainable reality.