In virtually every technological sector, nanotechnology is causing excitement and concern — and the prospect of its application to pesticides is no different. Yes, nanoparticles present endless possibilities for more efficient and effective control of pathogens, but our relative lack of information on how they act and how they can be contained are giving regulators pause before allowing their release into the environment.
Pesticides containing nanotechnology hold great promise for reducing the environmental footprint left by conventional pesticides. As EPA has noted, “these novel products may allow for more effective targeting of pests, use of smaller quantities of a pesticide, and minimizing the frequency of spray-applied surface disinfection. These could contribute to improved human and environmental safety and could lower pest control costs.” The predominant uses being discussed at present are in antibacterial products. Nanosilver, for example, could when used as a materials preserver maintain its ability to reduce odor-causing bacteria longer and require smaller quantities than other silver preservatives.
There is still time to devise sound, informed policy around the use of nanotechnology in pesticides. The EPA has not approved any pesticide products explicitly presented to it during the registration application process as containing nanoscale materials. But there are nevertheless pesticide products in commerce that contain nanotechnology, namely nanosilver. The reason for this is that EPA, before the advent of nanotechnology, registered products with silver as the active ingredient but did not specify particle size in the registration. These products were refined by their manufacturers over time to include smaller and smaller particles of silver without triggering any regulation that would require them to go back through the registration process
For this reason, EPA has announced that it needs more information on which products currently on the market — ones registered as conventional pesticides — do in fact contain nanoscale materials and has asked the public for advice on how it can find out. It has also asked the public to weigh in on the regulatory framework EPA should use to review and register new products containing nanotechnology.
On a Web site (www.epa.gov/pesticides/regulating/nanotechnology.html) devoted to pesticides containing nanotechnology, EPA concedes that “the special properties that make nanoscale materials of potentially great benefit also can present new challenges for risk assessment and decision-making” — not least of which are the unintended effects of their small size, which may allow them to pass through cell membranes or the blood-brain barrier. The agency, which in November 2009 asked a body of independent scientists to provide ideas for a regulatory approach to pesticides containing nanoparticles, has concluded that existing environmental law provides a good framework for regulating pesticides containing nanotechnology.
As a result, the agency on June 17 published a notice (www.regulations.gov/#!documentDetail;D=EPA-HQ-OPP-2010-0197-0001) in the Federal Register asking the public to submit comments on how best to apply existing law. Specifically, the agency asked for feedback on whether certain provisions of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) would allow it to obtain information regarding what nanoscale materials may already be present in registered pesticide products, and whether those provisions are sufficient to let it obtain information on nanoscale materials in new products that companies are seeking to register. Public comments were due by Aug. 17, and EPA is currently reviewing them.
If EPA does use FIFRA as its legal framework for regulating pesticides containing nanoscale materials, this will impact how much information consumers can expect to have. An EPA spokesperson contacted by LocalMotionGreen noted that labels for pesticides containing nanomaterials would be consistent with current labeling policies under FIFRA, which means that nanoscale materials acting as inert ingredients would be subject to confidential business information claims and therefore would not have to be disclosed on a label. However, the spokesperson said EPA is “looking at active ingredient designation options” for products containing nanotechnology, which means labels might end up declaring when pesticide formulations contain nanoscale materials. The policy is still under development.
The EPA spokesperson also confirmed that there is nothing in FIFRA that prevents nanotechnology from being used in a pesticide, provided EPA determines the product undergoing review “will not generally cause unreasonable adverse effects on people’s health or the environment.”
After EPA finishes reviewing public comment, it will develop a decision for publication in the Federal Register. This process can take many months, which means no pesticides containing nanotechnology will be registered in the near future. However, the EPA spokesperson said that the agency “routinely meets with applicants in preregistration meetings to discuss data requirements and the categorization of products that contain nanoscale materials.” Moreover, he said, the Office of Pesticide Programs has two pending registration applications for products containing nanoscale materials from two companies: HeiQ Materials AG of Switzerland and NanoSilva LLC of Florida. Both registrations involve nanosilver.
Meanwhile, in November scientists from Oregon State University and the European Union published a study (http://oregonstate.edu/ua/ncs/archives/2010/oct/new-approaches-needed-gauge-safety-nanotech-based-pesticides) in the International Journal of Occupational and Environmental Health outlining regulatory and educational issues “that should be considered whenever nanoparticles are going to be used in pesticides.”
Specifically, the researchers said that manufacturers should disclose exactly what nanoparticles are involved in their products and what their characteristics are; that compounds should be tested in the same way humans would be exposed to them in the real world; that future regulations should acknowledge the uncertainty that will exist for nano-based pesticides with inadequate data; and that tests should be done using the commercial form of the pesticides. The researchers also called for a health surveillance program and the development of public educational programs.
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