The Natural Resources Defense Council (NRDC) filed a federal suit against the U.S. Environmental Protection Agency on January 26, 2012, seeking to overturn EPA's decision to conditionally approve nanosilver under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). It marks the first time ever that EPA's approval of a nanoscale chemical has been challenged in court. The NRDC petition was filed with the 9th U.S. Circuit Court of Appeals, headquartered in San Francisco, Calif.

The NRDC petition claims that sales of the nanosilver-based pesticide should be halted because the health risks of the substance are unknown. The environmental advocacy group, which has been highlighting potential safety concerns about the use of ultra-tiny silver particles as an antimicrobial agent for several years, accused the EPA of giving the manufacturer a “four-year free pass” by allowing the pesticide to come to market before health and safety testing has been completed.
Nanosilver
Silver is a well-recognized antimicrobial, and being re-engineered in nanoform boosts its ability to kill bacteria. Consequently, companies have sought to use nanosilver in products as varied as workout gear (to stop odor), toothpaste (to kill bad-breath-causing bacteria) and humidifiders (to prevent mold growth). While the silver industry maintains that it’s been used safely for centuries, advocates like the NRDC are concerned about engineered nanosilver particles its uncertain impact on people and the environment. Other advocacy groups have also raised questions about nanosilver, and some academics are now making careers out of exploring the implications of the material, as I have discussed in a number of posts about the nanosilver debate over trhge past two years.
Last December, EPA granted "conditional registration" to HeiQ Materials' AGS-20 product, to be incorporated into fabrics, meaning the textiles could go on the market while the company conducts health and safety tests over the next four years. The AGS-20 product is essentially a composite of nanosilver and nanoscale silica. Part of the conditional approval was an EPA requirement for more testing on what the pesticide might mean for people, animals and the environment. But the NRDC suit, filed in federal court in California, says that’s not enough, and calls for testing before AGS-20 is sold.
The NRDC's Antipathy for Nanosilver
NRDC's press release announcing the federal suit was inflammatory: "EPA gave this company a four-year free pass to sell an inadequately tested product. EPA's approval of nanosilver is just the most recent example in a long line of decisions that treats humans and our environment as guinea pigs for these untested pesticides."
NRDC has long been part of the anti-nanotechnology crowd, publishing position papers and articles with such titles such as "Nanotechnology’s Invisible Threat: Small Science, Big Consequences," "The Promises and Pitfalls of Nanotech," and "Nanotechnologies and the Precautionary Principle."
With respect to nanosilver, the NRDC has been especially strident, stating in its blog
yesterday:
"Silver, a well-recognized antimicrobial, is highly toxic and kills both harmful and beneficial bacteria. Nanosilver is engineered from silver and marketed as an even stronger antimicrobial than silver. Because of its smaller size, nanosilver penetrates organs and tissues in the body that larger forms of silver cannot reach, like the brain, lung, and testes. That can't be good!"
Suit Timing is Interesting
The NRDC lawsuit unites two frequent advocacy-group criticisms of EPA: The agency's conditional approval program and the federal approach to nanomaterials. The suits comes on the heels of recent reports by both the EPA's inspector general and a National Academy of Sciences panel that said more attention needs to be paid to assessing the health risks posed by nanomaterials, and more funding and research needs to be devoted to it.
Coming on the heels of the recent EPA inspector general and NAS reports, and with other regulatory moves on nanomaterials percolating , the NRDC’s suit bears watching.