However, health scientists say the nanoparticles will wash out with the rinse water and could cause unknown environmental and health problems downstream.
The EPA said that it may issue "conditional approval" to HeiQ Materials AG, a producer of nanosized additives, for the use of a nanosilver pesticide as a new active ingredient in fabrics.
Jennie Hills, Getty Images
Nanotech socks like these could soon receive tentative EPA approval.
Over the past 11 years, clothing manufacturers, mostly from China, South Korea and other Asian countries, marketed a long list of clothing permeated with antimicrobial nanosilver, as AOL News reported in March.
Bras, panties, men's underwear, jogging outfits, camping clothing and a long list of other consumer products were being touted as "odor-free" or "germ-proof" because of the use of "the almost magical properties of nanosilver," some ads said.
The promise of being able to keep the same undies on for a week or more without offending those traveling with you, or wearing pants that are almost impervious to stains, or using baby bottles and teething rings that destroy bacteria initially attracted many shoppers and buyers for major national chains stores.
But sales of the novel products plummeted as public health activists widely spread the word that the safety and health effects of exposure to these antimicrobial nanoparticles had yet to be thoroughly tested by anyone, nor blessed by the EPA or the Consumer Product Safety Commission,
The public has been given 45 days to comment on the wisdom of EPA's proposal. If EPA is not forced to reconsider its approval, new lines of nano-infused clothing may soon be coming to stores near you.
Several studies show the pass-through of nanosilver in fabrics into the environment.
Last year, the Swiss Federal Laboratories for Materials Testing and Research, examined the "Behavior of Silver Nanotextiles During Washing." The study concluded that the widespread use of silver nanoparticles in commercial products, especially textiles, will likely result in an unknown spread of the nanomaterial into the environment.
And the EPA insists that HeiQ Materials AG will be required to conduct a litany of studies before permanent approval is granted.
"This conditional registration will allow the manufacturer to produce, market and sell its nanosilver product in the United States under the condition that the manufacturer provide the agency more extensive product chemistry, toxicology, exposure and environmental data," an EPA spokesman told AOL News.
Black Hole of Calcutta
Many in the public health community, including some within EPA itself, are not enamored with conditional approvals.
"The granting of conditional approval to these pesticides is the same as giving these chemical companies a 'get out of jail' card. In almost all cases the pending information never shows up, so the potential environmental and health ramifications are really never known," an EPA risk assessor told AOL News.
"It's the consumer and the workers using these chemicals that face the greatest risk, but the industry pressure on this agency for these approvals is enormous," said the toxicologist, who would not allow his name to be used because he is not authorized to speak to the press.
Jennifer Sass, senior scientist and nano expert for the Natural Resources Defense Council, calls the conditional approvals the black hole of Calcutta.
"It's a one-way hole where things get registered and then they never get tracked or reviewed again," she said.
"It seems that EPA does this way too often and then they have no organized system of tracking when, or even if, the data is received that was the condition of the registration -- let alone an evaluation of what the data actually says.
Sass' research shows that between February 1997 and June of this year, EPA has awarded the designation to 94 pesticides -- from Acequinocyl to Zoxamide -- and cited a litany of deficiencies that had to be met before full approval was granted.
Only 17 ever received full approval, she told AOL News.
Not This Time
The EPA spokesman said the approval in this case, should it be granted, has a four-year expiration date and it is legally binding, which means that if the company doesn't produce the mandated test results, the approval can be pulled.
"We anticipate that the company will be given three years to submit the data, and the agency has allowed itself one year to evaluate the data," the spokesperson explained.
The EPA says it will set a schedule for study submission and will maintain contact with the company to ensure that schedule is met.
The question of safety during this conditional approval period is still a concern to many, and EPA's answers to the questions of how it knows the new material is safe are both refreshing and worrisome.
For example, the agency's Antimicrobial Division, Office of Pesticide Programs, addresses the questions of safety of the nanosilver with phrases like it "will likely lead to low levels of human and environmental exposure and risks" or "the proposed conditional registration would not cause unreasonable adverse effects on the environment."
But around the country, scientists also working with antimicrobial nanoparticles are making discoveries that raise concerns.
At Duke University, biology researcher Ben Colman and the engineers, chemists, ecologists and toxicologists who collaborate with him continued Tuesday dousing pond weeds with nanosilver.
Earlier this month, Colman's group had reported that they has exposed different plants to the same amount of nanosilver that EPA studies had found in various water treatment facilities.
What he found and why he's doing additional testing is that some species of plants were 22 percent smaller than identical plants that weren't subjected to the antibacterial agents.
"This could be a concern if nanosilver continues to be released to the environment," he told AOL News.