On May 1, 2008, a group of 14 NGOs sued the EPA asking the agency to issue new rules regulating products containing nanoscale silver particles. The NGOs are: The International Center for Technology Assessment; The Center for Food Safety; Beyond Pesticides; Friends of the Earth; Greenpeace; The Action Group on Erosion, Technology and Concentration; Center for Environmental Health; Silicon Valley Toxics Coalition; Institute for Agriculture and Trade Policy; Clean Production Action; Food & Water Watch; Loka Institute; The Center for the Study of Responsive Law; and Consumers Union.
The petition points to the consumer product inventory published on the Project on Emerging Nanotechnologies website of the Woodrow Wilson International Center for Scholars which identifies approximately 260 products purporting to contain or use nanoscale silver. Petitioners claim the EPA has failed to adequately regulate these and other similar products.
In support of its call for new regulation, the petition takes the petition that while the specific long-term health effects of human and environmental exposure to nanoscale silver particles are still being studied, scientific studies “indicate that nanosilver materials pose serious risks to human health and the environment.” According to the petitioners, some of these studies allegedly show:
- Nanoscale silver is more toxic than other nanoscale metals. Braydich-Stolle, et al., In Vitro Cyctotoxicity of Nanoparticles in Mammalian Germline Stem Cells, 88(2): Toxicological Sciences 412-419 (2005)
- Nanoscale silver exhibits “effective antibacterial action” at much lower levels than silver ions. Lok, et al., Proteomic analyses of the mode of antibacterial action of silver nanoparticles, 5 J. Protean Res. 916-924 (2007).
- Nanoscale silver produces reactive oxygen species, which can result in toxic oxidative stress. Hussain, et al., In vitro toxicity of nanoparticles in BRL 3A rat liver cells, 19 Toxicology in Vitro 975-983 (2005).
- Nanoscale silver is toxic to mammalian liver cells. Hussain, et al., In vitro toxicity of nanoparticles in BRL 3A rat liver cells, 19 Toxicology in Vitro 975-983 (2005).
- Nanoscale silver is toxic to mammalian stem cells. Braydich-Stolle, et al., In Vitro Cyctotoxicity of Nanoparticles in Mammalian Germline Stem Cells, 88(2): Toxicological Sciences 412-419 (2005)
- Nanoscale silver is toxic to mammalian brain cells. Hussain, et al., In vitro toxicity of nanoparticles in BRL 3A rat liver cells, 19 Toxicology in Vitro 975-983 (2005).
- Mammalian cell function abnormalities result from contact with nanoscale silver. Hussain, et al., In vitro toxicity of nanoparticles in BRL 3A rat liver cells, 19 Toxicology in Vitro 975-983 (2005).
- Inhaled nanoscale silver may be transported throughout the body and into the kidney, brain, and heart. Health and Safety Laboratory, Health and Safety Executive NewsAlert Service, December 2006 at p. 26.
- Nanoscale silver penetrates cell membranes agglomerates in cell cytoplasm. Skebo, et al., Assessment of Metal Nanoparticle Agglomeration, Uptake, and Interaction Using High-Illuminating System, 26 International Journal of Toxicology 135 (2007).
- Nanoscale silver causes embryonic contamination in Zebrafish. Lee, et al., In Vivo Imaging of Transport and Biocompatibility of Single Silver nanoparticles in Early Development of Zebrafish Embryos, 1 ACS NANO 133, 141 (2007).
Because of these alleged risks, as well as others claimed in the petition, Petitioners ask EPA to take a litany of specific actions, including:
- Classify nanoscale silver as a new pesticide (or new use of an existing pesticide) and require detailed product registration and data submissions under the Federal Insecticide Fungicide and Rodenticide Act (FIFRA).
- Analyze the potential EHS risks of nanoscale silver under FIFRA, the Food Quality Protection Act (FQPA), the Endangered Species Act (ESA), and the National Environmental Policy Act (NEPA).
- Take action against unregistered products containing nanoscale silver including issuing stop sale and/or removal orders.
Finally, the petition appears to be driven by the EPA’s September 2007 public notice that it intends to regulate silver ion generators as pesticides under FIFRA. Petitioners do not believe that the notice went far enough in addressing potential nanoscale silver issues:
In the FR notice no mention is given to the rest of the existing fleet of nano-silver products (besides the “ion generating” equipment) or any proposed action by the agency regarding it, contrary to the reports of the quotes from EPA officials in the November 2006 announcement. Nowhere does the notice request information about such products or in any way solicit comment from interested parties or the public on the regulation of nano-silver products.