NRDC v. EPA

The Environmental Protection Agency is not obligated by statute to conduct an aggregate risk assessment before granting conditional registration for a pesticide that is not for food use, but if it does conduct an assessment and the margin of exposure exceeds the targeted exposure, that pesticide poses a credible threat to consumers.

HeiQ Materials AG (“HeiQ”) applied to the Environmental Protection Agency (“EPA”) for permission to use two pesticides, AGS-20 and AGS-20 U, on textiles to prevent growth of microbes that cause odor, stain, and degradation of textiles. Following a public comment period and risk assessment analysis, the EPA conditionally granted HeiQ registration of the pesticides. The National Resources Defense Council (“NRDC”) petitioned the Ninth Circuit to vacate the EPA’s decision. Under the Federal Insecticide, Fungicide, and Rodenticide Act, pesticides must be registered with the EPA before they can be sold. Part of the EPA’s process for determining which products are allowed to be registered involves testing to determine whether the product causes “unreasonable adverse effects” on human health or the environment. The Ninth Circuit found that although the EPA had only tested AGS-20 and AGS-20 U for effects on toddlers and not infants, the EPA supported its decision to do so with substantial evidence—toddlers were deemed to be the most vulnerable group of consumers of the product. Similarly, the panel found that the EPA’s decision to test exposure only to nanosilvers of AGS-20 and AGS-20 U was supported by substantial evidence and the EPA’s own regulations. However, the panel overturned the EPA’s decision that AGS-20 and AGS-20 U posed no risk to consumers. Although the EPA was not required to conduct an aggregate risk assessment for conditional registration of non-food pesticides, when the EPA did conduct the risk assessment, the margin of exposure exceeded the targeted exposure. Under EPA regulations, this excessive margin of exposure poses a “credible threat,” and mitigation is required before the product can be marketed. Petition GRANTED in part, DENIED in part, and REMANDED.