Federal Court Sends Conditional Registrations of Nanosilver Pesticides Back to EPA

by Brooks Pierce

Swiss company HeiQ Materials proposed to use new pesticides AGS-20 and AGS-20 (U) on manufactured textiles such as clothing, blankets, and carpet. Nanosilver is used in the pesticides to suppress microbes that cause odors and stains. The U.S. Environmental Protection Agency (EPA) granted conditional registration of the pesticides under the Federal Insecticide, Fungicide and Rodenticide Act, but a federal appeals court has now vacated part of EPA’s decision and remanded the case back to the agency.

The Natural Resources Defense Council (NRDC) challenged the nanosilver pesticide registrations on several grounds involving EPA’s risk analyses and decision to grant the registrations. NRDC’s claims focused on potential risks to consumers who use textiles treated with AGS-20. A majority of the three-judge panel of the United States Court of Appeals for the Ninth Circuit rejected NRDC’s primary challenges, finding the record supported two aspects of EPA’s assessment methodology: (1) EPA’s decision to use the characteristics of toddlers, rather than infants, as the subpopulation with the greatest risk of exposure; and (2) EPA’s decision not to consider additional sources of exposure to nanosilver as part of the AG-20 risk assessment. These two conclusions were hotly contested by the dissenting judge, who questioned the evidence to support the findings. The dissent also suggested that these findings should be disregarded because they were not essential to the Court’s decision to vacate EPA’s conditional registration of the nanosilver pesticides.

Where EPA erred, according to all judges on the panel, was in applying EPA’s own risk analysis guidelines. When deciding whether exposure to a pesticide might cause an adverse effect on humans, EPA first calculates a margin of exposure (“MOE”) target. For example, an MOE target of 10 translates to human exposure that is 10 times lower than the lowest dose expected to cause an adverse effect. A higher MOE score therefore suggests less cause for concern, because it provides a wider margin of safety. The target MOE incorporates a margin of safety to account for uncertainties in the assessment of pesticide risk, such as incomplete toxicity data, differential human sensitivity to pesticides, and uncertainty in extrapolating from animal studies.

In this case, EPA determined that a risk concern would be present with an MOE of 1,000 or less. When determining the actual (predicted) MOE score for AG-20 under various exposure scenarios, EPA calculated MOE’s between 1,000 and 3,600. EPA interpreted the MOE’s to suggest no cause for concern from exposure to AG-20. But the Court held that EPA ignored its own guideline that the new pesticides would pose a risk concern with a MOE less than or equal to 1,000. The Court vacated EPA’s decision based “solely on the fact that EPA’s own rule states that there is a risk concern requiring mitigation when the calculated MOE is less than or equal to 1,000 and, under these circumstances, the actual MOE equals 1,000.”

The Court rejected EPA’s argument that an MOE in the neighborhood of 1,000 does not mean that consumers are actually at risk: “Although EPA’s point is well taken as a practical matter, it is irrelevant as a legal matter.” The Court also rejected EPA’s argument that the true MOE actually exceeds 1,000 when calculated without rounding: “EPA’s data is not precise enough to allow it to ‘unround.’”

Going Forward

Even before the NRDC lawsuit was decided, EPA had already adjusted its risk assessment methodologies to consider children between six months and three years old when reviewing new applications for conditional registration. EPA had also planned to make further changes in response to an August 2013 report by the U.S. General Accountability Office, which recommended steps to improve the oversight of conditional registrations.

Though EPA’s conditional registrations of AG-20 were vacated (at least in part), the Court’s decision rests on the mundane proposition that a regulatory agency generally must follow its own rules. The Ninth Circuit’s decision in the NRDC lawsuit – especially the deferential review applied in the majority’s opinion dated November 7, 2013 – suggests that future conditional registrations of pesticides using nanoparticles will stand a good chance of being upheld so long as EPA diligently follows its own decision criteria.

DISCLAIMER: Because of the generality of this update, the information provided herein may not be applicable in all situations and should not be acted upon without specific legal advice based on particular situations.

© Brooks Pierce | Attorney Advertising

Written by:

Brooks Pierce

Brooks Pierce on:

Readers' Choice 2017
Reporters on Deadline

"My best business intelligence, in one easy email…"

Your first step to building a free, personalized, morning email brief covering pertinent authors and topics on JD Supra:
Sign up using*

Already signed up? Log in here

*By using the service, you signify your acceptance of JD Supra's Privacy Policy.
Custom Email Digest
Privacy Policy (Updated: October 8, 2015):

JD Supra provides users with access to its legal industry publishing services (the "Service") through its website (the "Website") as well as through other sources. Our policies with regard to data collection and use of personal information of users of the Service, regardless of the manner in which users access the Service, and visitors to the Website are set forth in this statement ("Policy"). By using the Service, you signify your acceptance of this Policy.

Information Collection and Use by JD Supra

JD Supra collects users' names, companies, titles, e-mail address and industry. JD Supra also tracks the pages that users visit, logs IP addresses and aggregates non-personally identifiable user data and browser type. This data is gathered using cookies and other technologies.

The information and data collected is used to authenticate users and to send notifications relating to the Service, including email alerts to which users have subscribed; to manage the Service and Website, to improve the Service and to customize the user's experience. This information is also provided to the authors of the content to give them insight into their readership and help them to improve their content, so that it is most useful for our users.

JD Supra does not sell, rent or otherwise provide your details to third parties, other than to the authors of the content on JD Supra.

If you prefer not to enable cookies, you may change your browser settings to disable cookies; however, please note that rejecting cookies while visiting the Website may result in certain parts of the Website not operating correctly or as efficiently as if cookies were allowed.

Email Choice/Opt-out

Users who opt in to receive emails may choose to no longer receive e-mail updates and newsletters by selecting the "opt-out of future email" option in the email they receive from JD Supra or in their JD Supra account management screen.


JD Supra takes reasonable precautions to insure that user information is kept private. We restrict access to user information to those individuals who reasonably need access to perform their job functions, such as our third party email service, customer service personnel and technical staff. However, please note that no method of transmitting or storing data is completely secure and we cannot guarantee the security of user information. Unauthorized entry or use, hardware or software failure, and other factors may compromise the security of user information at any time.

If you have reason to believe that your interaction with us is no longer secure, you must immediately notify us of the problem by contacting us at info@jdsupra.com. In the unlikely event that we believe that the security of your user information in our possession or control may have been compromised, we may seek to notify you of that development and, if so, will endeavor to do so as promptly as practicable under the circumstances.

Sharing and Disclosure of Information JD Supra Collects

Except as otherwise described in this privacy statement, JD Supra will not disclose personal information to any third party unless we believe that disclosure is necessary to: (1) comply with applicable laws; (2) respond to governmental inquiries or requests; (3) comply with valid legal process; (4) protect the rights, privacy, safety or property of JD Supra, users of the Service, Website visitors or the public; (5) permit us to pursue available remedies or limit the damages that we may sustain; and (6) enforce our Terms & Conditions of Use.

In the event there is a change in the corporate structure of JD Supra such as, but not limited to, merger, consolidation, sale, liquidation or transfer of substantial assets, JD Supra may, in its sole discretion, transfer, sell or assign information collected on and through the Service to one or more affiliated or unaffiliated third parties.

Links to Other Websites

This Website and the Service may contain links to other websites. The operator of such other websites may collect information about you, including through cookies or other technologies. If you are using the Service through the Website and link to another site, you will leave the Website and this Policy will not apply to your use of and activity on those other sites. We encourage you to read the legal notices posted on those sites, including their privacy policies. We shall have no responsibility or liability for your visitation to, and the data collection and use practices of, such other sites. This Policy applies solely to the information collected in connection with your use of this Website and does not apply to any practices conducted offline or in connection with any other websites.

Changes in Our Privacy Policy

We reserve the right to change this Policy at any time. Please refer to the date at the top of this page to determine when this Policy was last revised. Any changes to our privacy policy will become effective upon posting of the revised policy on the Website. By continuing to use the Service or Website following such changes, you will be deemed to have agreed to such changes. If you do not agree with the terms of this Policy, as it may be amended from time to time, in whole or part, please do not continue using the Service or the Website.

Contacting JD Supra

If you have any questions about this privacy statement, the practices of this site, your dealings with this Web site, or if you would like to change any of the information you have provided to us, please contact us at: info@jdsupra.com.

- hide
*With LinkedIn, you don't need to create a separate login to manage your free JD Supra account, and we can make suggestions based on your needs and interests. We will not post anything on LinkedIn in your name. Or, sign up using your email address.