Nanoparticles in food warning

Case-by-case approvals of nanoparticles in food and packaging are needed, even if larger particles of the same substance are already food-approved, according to the government-backed Central Science Laboratory (CSL).

Speaking at the Nutracon Europe conference in London, CSL principal scientist Dr Qasim Chaudhry said human studies into what happened to nanoparticles in the body were urgently needed. The imperative was underlined by in vitro analyses showing that "if something is less than 70 nanometres in size, it could potentially enter the cell nucleus and even damage DNA", he said.

"The threat is purely hypothetical, but it needs to be studied further," he added. "Exposure to some free-engineered nanoparticles has been shown to cause increased production of oxyradicals that may lead to oxidative damage and inflammatory reactions. If they get into cell tissues there is the potential to cause harm."

Nanosilver, an antimicrobial substance with potentially exciting applications as a preservative in flour or as a moisture-resistant edible food coating, might affect gut microflora in ways that were unclear, he added.

The food industry should also be responsible for labelling nanoparticles, even though it was not currently obliged to do so, he said: "If we have learned anything from the GM foods scenario, it's that you have to keep consumers in the loop. The industry should also form an approval authority that would certify things as nano or not as the term is bandied around without consistency."

Craig Simpson, an associate at the Brussels office of law firm Steptoe & Johnson, said that it might be necessary in some cases to amend existing European legislation on additives, novel foods and food contact materials to cover nanomaterials.

However, not all legislation considered size as a deciding factor or would in practice control the use of nanomaterials in substances already permitted under legislation, he said.