Bans and safety issues: the nanotech debate heats up

Nanomaterials should be assessed individually to determine their impact on human cells and the environment, the European Food Safety Authority (EFSA) asserts.

From the targeted delivery of key nutrients to more stable emulsions, anti-bacterial surfaces, gas or light barriers in packaging and moisture resistant food coatings, nanotechnology presents exciting opportunities.

However, it has also attracted a lot of controversy, with the Soil Association recently announcing a ban on engineered nano materials (ENMs) as part of a stand against a "hazardous, potentially toxic technology that poses a serious new threat to human health"

In a consultation document published last month, EFSA said: "It is not possible to satisfactorily extrapolate scientific data on non-nano chemicals and apply it to their nano-sized versions. Consequently, specific case-by-case risk assessments should be performed, based on data from safety tests applicable to the particular application."

The main potential concerns related to the small size and high surface area of nanoparticles, said EFSA: "Small size increases their ability to move around in the body in ways that other substances do not, while their high surface area increases their reactivity." Other uncertainties existed, "particularly in relation to characterising, detecting and measuring ENMs in food, feed or the body", it said. "There is also limited information on absorption, distribution, metabolism and excretion, as well as toxicity."

It went on to recommend a huge amount of further research into every aspect of the technology.

Detailed recommendations to monitor usage and applications of ENMs were also made although it is not clear how this would be achieved given that there is currently no legal definition of nanoparticles, no legal requirement for them to be formally authorised as novel foods and no requirement to label them on food packaging.

While the British Standards Institute recently published voluntary guidance on labelling for companies using ENMs, food manufacturers have been reluctant actively to label products for fear of drawing attention to the issue and potentially alarming consumers, said one industry source. "Adding 'this contains nanoparticles of titanium dioxide' to your product in the interests of transparency is all very well, but I can't see people doing it unless they have to. It looks like a warning."