A type of nanotechnology used in a wide range of consumer products to kill germs will be regulated by the Environmental Protection Agency (EPA) as part of a change in federal policy.
The EPA said on Wednesday that the decision will require manufacturers using bacteria-killing particles of silver to provide scientific evidence that they won't harm waterways or public health.
Environmentalists and others are concerned that nanosilver may be killing helpful bacteria and aquatic organisms as it enters the environment when discarded and may even pose a risk to humans. Nanosilver is used to kill germs in shoe liners, food-storage containers, air fresheners, washing machines and other products.
Most nanomaterials, some as small as one-millionth the width of a head of a pin, will not fall under EPA oversight at this point, but the decision to regulate nanoparticles of silver is the first move by the government to regulate any part of the nanotechnology industry.
The Washington Post reported the EPA's decision on Wednesday night on its Web site. The Daily Environment Report published the first story on the decision on Tuesday.
Nanotechnology aims to develop new materials and products by creating or changing materials at the atomic and molecular level. It is still so new a field, however, that its impact is largely underdetermined. Only last December, the EPA issued its first official report on the subject, a road map for potential regulation that raised questions about gaps in scientific knowledge, the risk management and potential effects of the new technologies.
Silver is among the most common type of nanomaterials marketed to consumers, of which more than 200 now exist, according to the Project on Emerging Nanotechnologies, which is funded by the Woodrow Wilson International Center for Scholars and the Pew Charitable Trusts.
EPA officials decided a year ago that washing machines were not subject to a major pesticide law, the Federal Insecticide, Fungicide and Rodenticide Act, or FIFRA, because they were considered devices.
But the agency reconsidered its decision after re-examining the regulations, deciding instead "that the release of silver ions in washing machines is a pesticide, because it is a substance released into the laundry for the purpose of killing pests," EPA spokeswoman Jennifer Wood said in an interview.
"This is now being considered a pesticide," Wood said. "So it does have to be regulated under FIFRA."