Last week NAAA submitted comments to the EPA on the biological evaluation (BE) for the reregistration of glyphosate. The EPA is required by FIFRA to review the registrations for all crop protection products every 15 years. As part of the reregistration process, the Endangered Species Act (ESA) requires the EPA to work with the Fish and Wildlife Service (FWS) and National Marine Fisheries Service (NMFS) to evaluate the potential risks each pesticide represents to threatened and endangered species and their designated habitat. To accomplish this mandate, the EPA conducts a biological evaluation for each pesticide being evaluated during reregistration.
The EPA used the Tier 1 model in AgDRIFT to estimate the drift from aerial applications for the biological evaluation, as they have every other endangered species evaluation, human health risk assessment, and ecological risk assessment. NAAA has commented to the EPA numerous times on why the Tier 1 model is not appropriate to use for modeling the potential drift from modern aerial applications. For our glyphosate BE comments, NAAA referred the EPA to a letter submitted to the EPA’s Office of Pesticide Programs in June of 2020 for a detailed analysis of all the inaccuracies of the Tier 1 model and how to use the Tier 3 AgDRIFT model to improve the accuracy of aerial drift estimates. NAAA is making headway with the agency on this issue and has a meeting scheduled later this month to continue to move the process along towards more standard use of the Tier 3 layer of the AgDRIFT model.
NAAA was also concerned the fine-medium droplet size was used for the subsequent modeling in the BE that estimates the potential exposure and harm to endangered species. The fine-medium droplet size was assumed to be used on all aerial applications of glyphosate for both ag and non-ag uses in these models, despite the fact the interim decision for glyphosate specified the use of the medium or coarser droplet size. The exception was if glyphosate is tank mixed with a fungicide or insecticide that requires a fine droplet size. NAAA pointed out that most aerial herbicide applications do not involve a fungicide or insecticide tank mix partner, and that when they do occur, many of the products also require a medium or coarser droplet size. Therefore, NAAA pointed out that is not appropriate to use the fine-medium droplet size for these other BE models either. NAAA also offered that tank mixes of glyphosate should all be labeled for medium or coarser droplets for aerial use to alleviate any remaining risk concerns that the agency may have.
Next in the queue for NAAA to comment on are ecological and human health risk assessments for a few fungicides commonly applied via aerial application, a proposed interim decision for propargite that is expected to contain deeply flawed recommendations, and more BEs.