No place for nanosilver in food - German risk body

10-Jun-2010 - Last updated on 15-Jun-2010 at 11:16 GMT

Nanosilver has no place in consumer products such as foods or cosmetics until the potential hazards from the substance have been fully scrutinised, the German Federal Institute for Risk Assessment (BfR) has said.

The body urged companies that are considering use of nanosilver in consumer products to hold off until studies have fully confirmed its safety. At present, the agency said the case had not been made.

“It is not possible at the present time to determine in a definitive manner whether nanosilver constitutes a health risk for consumers”, said a BfR statement.

Antimicrobial

The anitimicrobial properties of silver ions are well-established but the body said its call for caution cames as manufacturers begin to utilise silver particles in the nano-range. It cited the use of nanosilver to coat surfaces in fridges to inhibit the growth of germs as one example that appeared to cause potential concern.

“Until we are in a position to reliably rule out potential health risks, we recommend that manufacturers refrain from using nanosilver in consumer products”, said BfR president Professor Dr Andreas Hensel.

Nanomaterials consist of particles with a diameter of less than 100 nanometres. Their size means they exhibit different properties than those of larger particles of the same substance. Not enough is known about whether these differences in properties could have negative as well as positive consequences.

It has still to be ascertained whether their toxic properties change and they could become a health risk for consumers, said the German experts. The BfR called for more research to “elucidate the fundamental issues in conjunction with the use of nanoscale silver as an antimicrobial material” to determine at what scale consumers come into contact with nanoscale particles and the potential hazard of resistance development.

Unanswered questions

BfR recommended “refraining from using any nanoscale silver in consumer products until a definitive safety assessment becomes available”.

Given its ability to inhibit the growth of germs, silver is used in food dye E174 and cosmetics. Nanoscale additives in food require approval and the body hailed the fact that nanosilver has not been approved for use in this area yet.

“BfR welcomes this in the context of the yet to be answered questions about risk assessment,” it added.