The allure of nanosilver

A Remington electric shaver says nanosilver will decrease redness and irritation. The company AgActive touts that the SilverSure coating on its bedsheets will "fight against cross infection of superbugs such as MRSA [methicillin-resistant Staphylococcus aureus]." A website selling plastic food containers imbued with nanosilver reminds consumers that "a typical [hospital] infection can cost as much as $47,000 per patient to treat."

The website www.nanosilverproducts.com asserts that nanosilver will "improve blood circulation and metabolism" and "adds immeasurably to your well-being." And Helix curling irons are touted as a "natural bacteriostat" without any explanation of why bacteria on a curling iron may be problematic.

In September, the Environmental Protection Agency, concerned about a large number of nanosilver products claiming antimicrobial abilities, ruled that any device using silver to generate ions for the express purpose of killing organisms must go through a vetting process to determine that it poses no unreasonable risk to people and the environment.

At face value, the EPA ruling would seem to include any product using nanosilver as an antimicrobial; however, the EPA says that as a practical matter, only products that overtly claim to kill, destroy or mitigate pests will be targeted, requiring registration and vetting for hazard as a pesticide.

In March, the EPA fined a Southern California company, IOGEAR, $208,000 for making unsubstantiated antimicrobial claims about its nanosilver-coated computer mice and keyboards. The company has since stopped marketing the product as an antimicrobial or containing nanosilver, but it is under no obligation to stop putting nanosilver into its products. (IOGEAR declined to state if nanosilver was still an ingredient.)

A December 2006 report on nanoscale materials, prepared by the Food and Drug Administration, noted the proliferation of products using nanoscale silver and called for increased testing.

While the government and companies struggle to find a balance on this issue, the consumer is left with the option to buy nanosilver products or not.

"There are some pretty amazing claims that are being made, that these products will essentially cure anything," says Dr. Michael Bell, associate director for infection control at the federal Centers for Disease Control and Prevention. He says he is happy to have another weapon in the arsenal against bacteria. "But we need to do the studies to show benefit, and for whom -- and what downsides, if any, [there are] to using this [technology] on a wider scale."