Products laced with anti-germ silver face EPA rules

WASHINGTON — The Environmental Protection Agency has decided to regulate a large class of consumer items made with microscopic "nanoparticles" of silver, a new but increasingly used technology that may pose unanticipated environmental risks, a government official said Wednesday.

The decision — which will affect the marketing of high-tech odor-eating shoe liners, food-storage containers, air fresheners, washing machines and a range of other products that contain tiny bacteria-killing particles of silver — marks a key reversal in federal policy.

It also means an unexpected regulatory hurdle for the burgeoning field of nanotechnology, which involves the creation of materials just a few ten-thousandths the diameter of a human hair.

Until now, new products made with tiny germ-fighting particles of silver did not have to pass regulatory muster.

Impact on water

That has concerned environmentalists and others who think the growing amount of nano-silver washed down drains may be killing beneficial bacteria and aquatic organisms, and may also pose risks to human health.

Most nanomaterials, which by definition are on the scale of a billionth of a meter, will remain outside the purview of the decision. But experts said the move is the first federal restriction to focus largely on nanotechnology.

Under the new determination, confirmed Wednesday by the EPA, any company wishing to sell a product it claims will kill germs by the release of nanotech silver or related technology must first provide scientific evidence that the product poses no environmental risk.

"We will be able to evaluate them and ensure that these products are not going to do damage to the aquatic environment," said Jim Jones, director of the EPA's Office of Pesticide Programs.

Sean Murdock, executive director of the NanoBusiness Alliance, a trade organization for companies that make or use nanomaterials, said he had not seen details of the plan and could not predict its effect on the industry.

Jones said the final rules will be spelled out in the Federal Register in the next few months.

He acknowledged, however, that the oversight will apply only to products advertised as germ-killing.

Loophole problem

"Its sounds like a major legal loophole and is probably something that will have to be dealt with in the courts," said Mae Wu, an attorney with the Natural Resources Defense Council, which has been pushing the EPA to regulate nanosilver.

Conventional materials, such as carbon or gold, exhibit unconventional properties when manufactured on a nanoscale. That is largely because the tiny particles have relatively large amounts of surface area for their small mass, which makes them very chemically reactive.

Carbon, for example, does not conduct electricity well in its bulk form but does so very well when spun into fibers a few nanometers in diameter.

While bulk gold hardly reacts with substances around it, gold nanoparticles can destroy bacteria and other living cells.

Silver can kill microbes even in bulk form but is more efficient as nanoparticles. Nanosilver can be easily incorporated into a variety of products, such as food containers or shoe liners — which has made it the most common type of nanomaterial marketed to consumers.

Nanosilver also has been added to bandages to speed healing. That use and others in which the particles are applied to the body are regulated not by the EPA but by the Food and Drug Administration, which is considering whether it needs new rules for nanoproducts.