NRDC reveals failed safeguards for pesticides - bad-actor pesticides, including nanosilver and the "neonics," approved through "conditional registration" loophole

The public may think pesticides are only allowed onto store shelves and for use in agriculture if they have been approved by the U.S. Environmental Protection Agency (EPA) in a transparent and scientifically rigorous process. Our investigations, however, reveal a deeply flawed system that has allowed the majority of pesticides onto the market without a public and transparent process, and in some cases without a full set of toxicity tests, using a loophole called a conditional registration. As many as 65% of more than 16,000 pesticides were first market-approved using this loophole, including nanosilver and the neonicotinoid pesticides that are linked to bee deaths.


Silver has long been known to be an effective germ killer and has been registered since the 1950s as an antimicrobial pesticide. Nanosilver was conditionally approved by EPA as an antimicrobial agent in textiles including clothing, without rigorous toxicity testing to evaluate risks. The small size of the nanoparticle means it can go places that the conventional silver cannot. EPA’s review of the data submitted for the conditional registration application included two studies of rats given oral doses of nanosilver over 28 days and 90-days. The studies showed a dose-dependent increase in silver distribution in the liver, kidneys, stomach, brain, lungs, testes and blood, providing some experimental evidence that once inside the body, ingested nanosilver will travel throughout the body to access many organs and tissues.  Not just ingested, but also inhaled nanosilver, has been reported in rodents to end up in the brain, according to EPA’s data review.

In granting the conditional registration for nanosilver, EPA acknowledged that people will be in direct contact with nanosilver from these products, including workers who make the clothing, consumers who wear it, and infants and babies who lay against their parents clothing and suck or chew the treated clothing. Nanosilver will leach from clothing into wash water and has been shown to go from treated clothing onto skin in artificial laboratory tests using artificial human sweat to facilitate leaching.  EPA should have required a complete set of reliable data on potential risks to people and wildlife, including studies of risks from long-term exposures, before making its registration decision.


Pollinators, including bees, bats, and butterflies, contribute approximately $15 billion to the economy through the pollination of over 130 cash crops, making up approximately one-quarter of all the foods in the human diet.  Without pollinators there would be no almonds, pumpkins, cherries, apples, or many other favorite foods. Unfortunately, beekeepers have been suffering bee colony losses of about 30% annually since 2007, likely from a combination of environmental stressors, parasites, pathogens, and pesticide residues in the bee hive.  The neonicotinoid family of pesticides - which includes clothianidin, imidacloprid and thiamethoxam - are key suspects because they are systemic (taken into and distributed throughout the plant tissue), persistent and highly toxic to honey bees. They were developed as a less-toxic alternative to organophosphate and carbamate pesticides, which are not only highly toxic to bees, but also highly toxic to wildlife and to people. However, because organophosphates are not systemic, they do not contaminate the pollen and nectar of treated plants.

Clothianidin (sold under the trade names Poncho®, Poncho®Beta, and Prosper®) is a product of Bayer CropScience. It was conditionally registered in 2003 as a treatment for corn seed and canola seed. The registration was conditioned upon, among other things, the completion of a field study of effects on bees. Bayer’s bee field study determined that clothianidin could be used safely. Clothianidin’s registration was switched from conditional to fully registered in April 2010, despite the fact that EPA determined the bee field study contained a number of serious flaws, including cross-contamination of pesticide treated and untreated fields, and failure to accurately count dead bees.

In fact, a 2012 study conducted by scientists from Purdue University found that during planting of clothianidin-coated seeds a powdery talc blew off the seeds and contaminated the farm machinery with as much as 700,000 times the bee’s lethal dose of pesticide.  However, EPA relied on studies submitted by Bayer CropScience that failed to find harmful effects on bees from clothianidin-treated seeds.

To our knowledge, none of the flaws in the pollinator field study were remedied nor was there a new study, and the potential risk of clothianidin to bees remains undetermined. Yet EPA allowed clothianidin to be fully registered without making the new studies available for public review that may have caught these problems.


EPA is conditionally registering pesticides without critical data or with poor quality data.  EPA decisions made later about whether the conditions imposed on these registrants have been satisfied are done in the dark – without any opportunity for the public to review or comment on EPA’s decision.  Since EPA lacks a proper database to track the progress of all of the registrations, use of the conditional registration provision is a black hole where decisions lack transparency, there are no opportunities for public review and comment, and EPA is not held accountable.

EPA should immediately cancel pesticide registrations with overdue studies or those that are out of compliance for any other reason.

EPA should immediately cancel the registration for clothianidin and the other neonicotioid pesticides because of their harm to bees.

Because of the missing studies in its application, EPA should cancel the conditional registration for nanosilver in textiles, and punish companies using it in consumer products without having gone through the proper registration process.


NRDC’s conditional pesticide report can be found here

In addition, today OnEarth Magazine, which is affiliated with NRDC, has published a story about the issue, which can be found here

The book Late Lessons From Early Warnings, Vol II (2013) contains chapters on the risks and health concerns with nanomaterials, and with the neonicotinoid pesticides.

About the Authors

Jennifer Sass

Senior Scientist, Federal Toxics, Health and Food, Healthy People & Thriving Communities Program

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