The Environmental Protection Agency has decided to regulate a large class of consumer items made with microscopic "nanoparticles" of silver, part of a new but increasingly widespread technology that may pose unanticipated environmental risks, a government official said yesterday.
The decision -- which will affect the marketing of high-tech odor-destroying shoe liners, food-storage containers, air fresheners, washing machines and a wide range of other products that contain tiny bacteria-killing particles of silver -- marks a significant reversal in federal policy. It also creates 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 muster with regulators. That has concerned environmentalists and others who think that the growing amount of nanosilver 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 new EPA decision. But experts said the move is the first federal restriction to focus largely on nanotechnology, an emerging engine of technological innovation that promises major advances in materials science and medicine.
"This is something of a test case," said Andrew Maynard, chief scientific adviser for the Project on Emerging Nanotechnologies at the Washington-based Woodrow Wilson International Center for Scholars.
"Nanotechnology can mean so many different things," Maynard said, because the technology is used to make a variety of products. "Specific examples like this will gradually help us make clear decisions as to whether existing regulatory approaches are adequate."
Under the new determination, first reported on Tuesday by the Daily Environment Report, a Washington publication, and confirmed yesterday by the EPA, any company wishing to sell a product that it claims will kill germs by the release of nanotech silver or related technology will first have to provide scientific evidence that the product does not pose an 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 sometime in the next few months. He acknowledged, however, that the EPA oversight will apply only to products advertised as germ-killing -- a detail that at least one major retailer has apparently noted.
The Sharper Image, which until recently advertised as anti-microbial several products containing nanosilver, has dropped all such references from its marketing materials.
In such cases, Jones said, the EPA will not act. "Unless you're making a claim to kill a pest, you're not a pesticide," he said.
Advocates of tougher regulation oppose that approach.
"Its sounds like a major legal loophole and is probably something that will have to be dealt with in the courts," said Mae Wu, a lawyer at the Natural Resources Defense Council, which has been pushing the EPA to regulate nanosilver.
Efforts to reach an official at the Sharper Image were unsuccessful.
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 surface areas 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. And though bulk gold hardly reacts with substances around it, nanoparticles of gold can burn up bacteria and other living cells.
Silver can kill microbes even in bulk form but is more efficient as nanoparticles. Nanosilver also can be easily incorporated into a variety of products, such as food containers and shoe liners. That characteristic has made it the most common type of nanomaterial marketed to consumers, according to a database of about 350 nanoproducts maintained by the Project on Emerging Nanotechnologies.
Nanosilver has also 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 currently considering whether it needs new rules for nanoproducts.
One product, a "Silver Wash" clothes washer made by Samsung, had in the past year drawn particular attention from the EPA because of claims that it sanitized clothes in cold water by releasing tiny charged particles of silver into the wash water.
In a statement yesterday, Samsung said that "only very minute, inactive forms of silver are discharged into the environment" by its washing machine. "Samsung has and will continue to work with the EPA and state regulators regarding regulation of the silver washing machine to maintain full compliance with all applicable laws and regulations," the company said.
About a year ago, Jones said, the EPA decided that such products did not fall under his office's major regulatory tool, the Federal Insecticide, Fungicide, and Rodenticide Act, or FIFRA. That is because FIFRA requires that pesticidal chemicals be proved safe before they are marketed but exempts pesticidal "devices."
In effect, Jones said, the agency considered the washing machine more of a mouse trap than a mouse poison, which meant that it was not subject to regulatory review.
‘A second look’
Among those disagreeing with that ruling was Chuck Weir, chairman of Tri-TAC, a technical advisory group for wastewater treatment plants in California. Those plants are subject to penalties if the water that leaves their stations is toxic to aquatic organisms.
In a letter to Jones in January, Weir asked the EPA to rethink its decision on nanosilver. "Silver is highly toxic to aquatic life at low concentrations and also bioaccumulates in some aquatic organisms, such as clams," Weir wrote.
Under pressure from other groups as well, the EPA decided to reconsider.
"We took a second look at the release of silver ions, and it was very clear that this is a pesticide and not a device," Jones said. "Our original determination proved not to be a correct one."