On Monday NAAA submitted comments to the EPA on the proposed interim decisions of three active ingredients in the Triazine family: Atrazine, Propazine, and Simazine. The EPA is required by FIFRA to review the registrations for all crop protection products every 15 years. Interim decisions are being used by the EPA instead of a full re-registration of a product because Endangered Species Act and pollinator protection assessments still need to be completed for most products.

For Atrazine and Propazine, the proposed drift mitigation for aerial applications to be put on the labels containing these active ingredients were largely acceptable. Similar to many recent proposed interim decisions, the label would set the limit on wind speed to 15 mph with the additional requirement for applying in wind speeds of 11 to 15 mph being that the boom length be reduced to a maximum 65 percent of wingspan for fixed wing aircraft and a maximum of 75 percent of rotor diameter for helicopters. For applications at wind speeds of 10 mph or lower, maximum boom length would be 75 percent of wingspan for fixed wing aircraft or 90 percent of rotor diameter for helicopters. Swath displacement will be ½ swath on the downwind edge of the field when winds are 10 mph or less, and ¾ swath on the downwind edge of the field when wind speeds are between 11-15 mph.

For Atrazine, the proposed interim decision recommends restricting aerial applications to only the liquid formulations and prohibiting the aerial application of the dry flowable/water dispersible granule (DF/WDG) and water-soluble packet (WSP) formulations. This proposed restriction seems to be largely based on EPA’s estimate for the high number of acres of crops treated daily with an agricultural aircraft. NAAA pointed out that the EPA should not assume exposure risk will increase simply because more acres are treated. If PPE and engineering controls are being used properly, the risk to the handler should be low no matter how many acres are treated. NAAA also pointed out that while it is possible for an agricultural aircraft to easily treat the number acres used by the EPA in their risk assessments, the reality is that the demand for aerial application of Atrazine to many of the crops on which it is applied is much lower. The NAAA used the results from the 2019 industry survey to back this assertion up by documenting the normal acres treated daily by a single aircraft.

Aerial application of Simazine is currently prohibited, and the proposed interim decision continues that prohibition. In reviewing the proposed interim decisions and risk assessments for all of the Triazines, NAAA could find no reason why aerial application of Simazine should be prohibited but allowed for Atrazine and Propazine. NAAA pointed this out in the comments and requested that this prohibition be reversed.