SAN FRANCISCO (CN) - Environmentalists urged the 9th Circuit on Wednesday to upend approval of a fabric antimicrobial that they say will end up in infants' mouths.
Swiss high-tech company HeiQ manufactures the antimicrobial pesticide AGS-20, marketed in Europe as "Pure." HeiQ says that the "unique silver microcomposite" is applied topically to fabric, "making it possible to keep garments naturally odor-free for the lifetime of the product."
The EPA granted conditional registration for AGS-20 under the Federal Insecticide, Fungicide and Rodenticide Act in 2011, despite finding that it could expose workers, consumers and the environment to silver ions, and that nanosilver could break away from AGS-20 particles.
It nevertheless concluded that "human health or ecological risk from exposure to silver ions derived from AGS-20 treated textiles is not of concern."
The Natural Resources Defense Council petitioned the 9th Circuit in January 2012 to overturn the EPA decision, claiming that the agency had ignored its comments regarding products for infants and children.
At a hearing before a three-judge panel Wednesday, NRDC attorney Catherine Rahm underscored the EPA's failure to use "the most vulnerable age group" in its studies of AGS-20 as required by law.
"EPA must find no adverse effects on human health, and must use the most vulnerable age group in its studies to make its determination," Rahm said. "EPA chose to do its risk assessments using 3-year-olds rather than infants."
Judge Jay Bybee asked: "What would EPA have to do here, use 2-year-olds, 1-year-olds?"
Rahm pointed out that the EPA's own studies showed that oral injection of AGS-20 resulted in the highest exposure, posing serious risks to very young children who are also very active chewers.
"The record shows that 1-year-olds and 2-year-olds are more likely to chew fabric and have lower body weight," Rahm said. "3-year-olds have higher body weight and are less likely to chew fabric. EPA found no adverse risks at all, and NRDC commented that it should incorporate mouthing risks to infants and very young children."
Judge Joseph Farris acknowledged the risks of nanosilver but questioned whether its ban was practical.
"There is a risk of nanosilver, and no one can argue that there isn't when you read this," Farris said. "But what about stairs? Do we stop building stairs? Can we make everything safe for everyone all the time?"
Rahm said the EPA's mistake was failing to consider the aggregate effect of AGS-20 and other silver-based antimicrobials already on the market. The agency didn't look at "whether adding AGS-20 would combine with them in consumers' bodies to cause even more harm," she said.
Dismissing the aggregation argument in his argument for the EPA, Justice Department attorney Matthew Henjum said that the agency is not required to perform aggregate studies in its risk assessments.
He insisted that the NRDC waived its opposition to the conditional approval by not objecting more forcefully during the public comment phase.
Noting the low threshold for standing to challenge EPA decisions, Bybee urged the government to drop the waiver subject completely.
"We've got affidavits in the record from parents who said 'Look, we're very concerned about this,'" Bybee said. "These products are going to be everywhere. Unless there's a label parents aren't going to know what they want to purchase has nanosilver."
Henjum acknowledged that the EPA has estimated potential leeching exposure at 35 percent when a 3-year-old chews or wears nanosilver-treated textiles.
He pointed out, however, that the agency's binding rules forbid treated products from containing more than 0.002 percent of silver by weight, meaning very little silver will end up in children's bodies.
Drawing fire from the panel, Henjum insisted that the EPA does not even have evidence that AGS-20-treated products release nanosilver.
"How can EPA find no adverse risks when there are unknown risks," Bybee asked.
Judge Lynn Adelman added: "And shouldn't EPA have done the additional testing before the conditional registration?"
In reply, Henjum said that the other scientific studies showing no risks led the EPA to decide against additional testing.
The agency made "extremely conservative assumptions" modeling a 3-year-old who wore AGS-20 treated textiles while simultaneously chewing on them, he said.
Henjum also defended the EPA's use 3-year-olds in tests, having long identified them as the most vulnerable consumer to textiles.
"This is a presumption EPA has developed over time based on its institutional expertise," Henjum said, adding that an independent advisory panel of scientists has ratified the agency's decision.
HeiQ attorney Matthew Shatz, a partner at the firm Manatt, Phelps and Phillips, dismissed NRDC's criticism of the EPA's choice to study toddlers rather than infants.
"Whatever group the EPA fixes upon, the activist groups say, 'Oh you didn't look at pregnant women or the elderly,'" Shatz said. "Or if you looked at 2-year-olds, they say 'You should have looked at 1-year-olds."
Judge Farris shot down Shatz's recommendation to waive the NRDC's claim.
"The difficulty with the waiver argument is we rule on it and then we find out 'uh-oh, a lot of babies are going to suffer,'" Farris said.
Bybee asked Shatz if the finished products treated with AGS-20 would come with a warning label. Shatz pointed out that HeiQ "is in the business of making coating material - it doesn't make the fabrics."
"Actually," Shatz added, "the idea here is that because this is an added feature of the product, it would be revealed maybe not so much as a warning, but as part of the advertising."
"It's going to be called something other than AGS-020," Bybee said. "It's going to be called 'super coating that makes you not stinky.' And that's very different from saying, 'This contains nanosilver that you don't want to let your infants chew on.'"
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