Atrazine and two other triazine crop protection compounds have been under some sort of ongoing EPA review or "special review" since 1994. Despite at least 27 years of activist human health and water quality attacks on one of the most studied, safest, and most effective herbicides, now it's endangered species concerns that may lead to label changes, rate limitations or new setbacks that could render the products ineffective and useless.

That's because EPA has published a “draft biological evaluation” for the triazines (including atrazine, propazine and simazine). It contains some troubling findings. Farmers have until February 19 to comment.

In September 2020, the EPA announced its Interim Registration Decision for the triazines in its periodic, regular reregistration review process that began in 2013 and is required by the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). Despite decades of continued, unfounded issues raised by activists about the products, the EPA's decision (once again) that the product is safe resulted in the labeled rate for atrazine in Iowa remaining unchanged at 2 pounds per acre for a single preemergence application on non-highly erodible soils, and 1.6 pounds per acre on highly erodible soils. Atrazine is the most widely used, effective and safe herbicide used on Iowa corn, applied on at least 56 percent of Iowa acres in 2018 to control broadleaf weeds at an average rate of 1.037 pounds per acre.

EPA Biological Evaluations

In the next step of the reregistration process, EPA is now seeking comments on its relatively new threatened/endangered species biological evaluations process (required from litigation over the Endangered Species Act). EPA now makes “effects determinations” for 1,795 listed species and 792 designated critical habitats when an already approved pesticide is used according to its label. The specific determinations categories include no effect (NE), not likely to adversely affect (NLAA), and likely to adversely affect (LAA).

The EPA’s "draft screening" biological evaluation for atrazine, propazine and simazine finds:

  • Atrazine is likely to adversely affect 54 percent of all species and 40 percent of critical habitats;
  • Propazine is likely to adversely affect 4 percent of all species and 2 percent of critical habitats; and,
  • Simazine is likely to adversely affect approximately 53 percent of species and 40 percent of critical habitats.

Yet there are significant concerns with the methods used by EPA to make these biological evaluations, including:

  • For the last four years of the ongoing registration process for atrazine and the other triazines, EPA has failed to review, acknowledge and incorporate all of the best available science into its September 2020 Interim Registration Decision.  This is a statutory requirement of FIFRA that should change the data used by EPA for its biological evaluations.
  • Instead, EPA has used suspect methodology, low-quality studies and broad species screening tools that result in too-conservative ecological endpoints for birds, fish and amphibians. Clear, high-quality science standards in FIFRA ensure the reregistration of these important crop protection compounds are based on good science, but highly questionable toxicology data used by EPA remains on the record. (The flawed process has even resulted in an extinct species being counted as threatened.)
  • EPA can and is now using the suspect science for its new biological evaluation, despite not being able to use it in the FIFRA registration process. Its use in the new biological evaluation process will likely later result in the loss of atrazine, or, unnecessary, cost-prohibitive mitigation practices and ineffective rates that will render the products useless.
  • Also, this same EPA biological evaluation process is now or will be impacting other crop protection compounds, such as glyphosate and dicamba. Each product you use on your farm will someday have to survive this new science "low-bar" that allows EPA to include almost every species in its evaluation. 

Once the EPA biological evaluation is final following the comment period, the U.S. Fish & Wildlife Service and the National Marine Fisheries Service will use it as their baseline as they conduct a required national threatened and endangered species assessment and render a “’biological opinion” for the triazines in accordance with the Endangered Species Act (ESA), which must be completed before the Interim Registration Decision is final in 2023 (a process regulated by FIFRA).

The use of the EPA’s faulty science now - allowed by the ESA due to a lack of data quality standards similar to those of FIFRA - is expected to jeopardize the ability of the services to render a biological opinion consistent with the FIFRA data standards used by EPA to reregister the product. There are questions about the capacity or the willingness of the services to sort through the suspect data. If this happens, the EPA may later restrict product rates and/or require new mitigation practices on already-approved labels.

What You Can Do

You can use this link to tell EPA how you use atrazine (such as in high residue, conservation tillage systems), and how it helps you reduce soil erosion and reduce nutrient loss (due to less tillage). Tell EPA how expensive other product alternatives might be for your cropping system. Explain to EPA the impacts of requiring additional mitigation or conservation practices that are not supported by sound science, or how reduced application rates make its use less effective. Explain to EPA how the loss of atrazine will likely hurt your efforts to help implement the Iowa Nutrient Reduction Strategy.

Send your comments to EPA no later than Feb. 19, 2021.