An antimicrobial chemical used to treat textiles is expected to get EPA approval, despite concern over the potential health risks associated with its microscopic parts, known as nanoparticles, attorneys say.
The EPA recently extended to March 30 the public comment period on a proposed registration by Georgia-based Poly-Technical Solutions LTD for Polyguard, which uses nanosilver particles to protect textiles from microbes and bacteria. The agency is also evaluating whether those products should be regulated under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA).
Nanosilver is part of a family of particles that are less than 100 nanometers across. As a comparison, a human hair is approximately 80,000 to 100,000 nanometers wide.
The agency’s preliminary conclusion is that Polyguard’s nanosilver ingredient meets FIFRA standards for use as a textile preservative.
But scientists, as well as public health and environmental groups, have raised concerns about the potential risks of nanoparticles in consumer products. The particles are so tiny, they can penetrate cell membranes, damaging DNA and increasing the risk of cancer, according to the American Association for Cancer Research.
The final verdict on Polyguard’s registration could open or close the door for similar nanoparticle pesticides, attorneys say.
“Certainly people are watching this, and not just from nanosilver, but also from perspective of other antimicrobials,” said John McGahren, a partner at Morgan, Lewis & Bockius LLP, where he’s deputy chairman of the firm’s global environmental practice.
Of particular concern to his clients, McGahren said, is the regulatory hurdles for registering antimicrobial products, a costly and time-consuming process which often stretches six years or more.
“If you’re a smaller company, trying to make antimicrobial claims, the registration process can cost upwards of a million dollars,” he said. “It is a barrier to registration and people are addressing that in all different kinds of ways.”
Avoiding the Past
Nanosilver has proven effective against infectious microorganisms, which makes it an attractive feature against “super-bugs” resistant to antibiotics.
If the EPA approves the nanosilver-containing Polyguard, the product would be incorporated into finished textiles to control the growth of odor-causing bacteria, mildew, mold, fungus, and algae. It would also prevent deterioration, staining, and discoloration of the textile products.
The Natural Resources Defense Council and the Center for Food Safety successfully challenged the EPA’s conditional registration of “NSPW-L30SS,” a nanosilver-based product used as a non-food contact preservative to protect plastics and textiles. The U.S. Court of Appeals for the Ninth Circuit in 2017 found the EPA failed to show the product was in the public interest.
But several attorneys suggested that Polyguard may avoid the legal challenges that have blocked nanosilver registration in the past.
Lynn Bergeson, managing partner of Bergeson & Campbell P.C., said Polyguard’s registration application is much more targeted, for use only on textiles.
“It’s also formulated differently, it’s not in a liquid suspension (like NSPW-L30SS), it’s in the form of a plastic bead or pellet,” she said.
Bergeson said nanosilver is already used in a number of consumer products including washing machines, refrigerators, and devices used to disinfect drinking water or swimming pools.
It’s unclear what, if any, environmental regulation such products need. The EPA in 2018 outlined its plan for evaluating whether some existing registered products are actually nanosilver products and, if so, what new requirements those products may need to meet under FIFRA.
“There are many other currently registered products containing elemental particulate silver that arguably meet EPA’s definition of a nanoscale material,” Bergeson said. “But these products haven’t been reclassified as nanosilver at this time.”
Jaydee Hanson, policy director at the Center for Food Safety, said the EPA is moving slowly in the right direction with nanosilver by limiting the range of uses to fewer products. But he said the agency is still making a number of broad assumptions without data to support them.
“They’ve failed to collect data about potential exposure routes for nanosilver products, including textiles, which toddlers or pets could chew or put in their mouths,” he said. “Another challenge is how do you accurately test the actual product, and what data do you have which suggests that other kinds of nanosilver work the same way?”
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