This week NAAA submitted comments to EPA regarding the proposed interim decisions (PID) for chlorothalonil and triadimefon. PIDs are the last stage in the pesticide registration review process before the endangered species evaluations. The word “interim” is used to designate that a PID could change after the endangered species evaluations.

 

Both PIDs retained aerial application on the label and had mostly acceptable label requirements for making aerial applications. These included a 10-foot release height (unless higher is required for safety), medium or coarser droplet size, maximum boom length restrictions of 75% or less of the wingspan for fixed-wing aircraft and 90% or less of the rotor diameter for helicopters, and a ½ swath upwind displacement on the downwind edge.

 

One restriction on both PIDs that NAAA opposed was a maximum wind speed limit of 10 mph. NAAA reiterated prior comments to EPA on why aerial applicators should be allowed to apply in winds up to 15 mph, and how the risk assessments EPA used to determine 10 mph was necessary are based on inaccurate and outdated modeling.

 

Both PIDs required a wind-directional buffer zone to protect conservation areas, which NAAA fully supported. The PID for triadimefon also proposed wind-directional buffers to protect aquatic areas, but the PID for chlorothalonil proposed a buffer zone no matter what direction the wind is from. NAAA recommended EPA change this to a wind-directional buffer zone, just like the buffer zone for conservation areas.

 

As 2024 approaches, NAAA expects more action from EPA regarding the protection of endangered species and is ready to review and comment as necessary to ensure aerial applications are not eliminated. Years of commenting on pesticide registration review decisions and directly engaging with EPA staff on aerial application issues has resulted in NAAA being well positioned to continue ensuring aerial application remains on pesticide labels.