Nanowerk reports that the German branch of Friends of the Earth (BUND) is calling for Samsung to withdraw from the market its washing machine using silver nanoparticles:
…BUND criticized that considerable amounts of silver could enter sewage plants and seriously trouble the biologic purification process of the waste water. In addition, silver nanoparticles were blaimed to have a toxic effect on different kinds of cells.
Samsung tells how it works:
Samsung WM1245A Washing Machine releases over 400 billion silver ions which penetrate deep into fabrics of any kind and create a coat of sterilizing protection for a maximum of 99.99% disinfection and an added antibacterial effect of up to 30 days after washing.
So, is BUND correct in making their demand that the product be withdrawn? Samsung rebuts:
Samsung countered that only an accumulated amount of 0.05 grams of silver are released per machine and year, while the released silver-ions quickly bind to non-nano-sized structures in the water. Therefore, the threat should be minimal. Any toxic effect of nanoparticles has to be considered together with the kind, size and modification of the particles. General predictions on the toxicity of nanoparticles are not possible.
So, Samsung is saying that their silver nanoparticles kill bacteria inside the washing machine, and also kill bacteria for up to 30 days on the clothes themselves — presumably after they have also gone through the dryer — but are harmless in the water coming out of the washer into the wastewater system and will not kill beneficial bacteria downstream.
It is possible that this is true. However, it makes absolutely no sense for Samsung to assume that people outside the company, who have seen no technical data to back up this claim, will automatically believe their statement. How is it possible that a company the size of Samsung, which sells products in European countries with very high environmental standards and concerns, could make this error?
To dig deeper, see David Berube’s Nanohype blog post on the topic. If Samsung has data to prove their claim, as they say they do, they should release it. Otherwise, these protests will keep happening, and rightly so.
This issue is a bit discouraging. If we have this kind of trouble over such a simple matter, how will we deal with the more complex challenges posed by nanodevices and advanced molecular nanosystems? —Christine