Current EPA Actions

Current EPA Regulatory Actions for Atrazine

May 3, 2016 — EPA Removes Refined Ecological Risk Assessment for Atrazine from EPA website

On Tuesday, May 3, 2016, EPA removed the Refined Ecological Risk Assessment for Atrazine from its own website, claiming that the signed document was not finalized. EPA officials were quoted in the media as saying the report would be released in “a few months”. EPA’s accidental posting of the report came on the heals of the agency’s accidental posting and subsequent removal of a report on another herbicide, glyphosate.

April 29, 2016 — EPA Posts Refined Ecological Risk Assessment for Atrazine

Quoted from the front page of the EPA report published online on 4-29-16. The report was dated 4-12-16.

The report recommends an aquatic life “Level of Concern” (LOC) of 3.4 parts per billion, dramatically lower than the 10 ppb LOC currently being used by EPA.


This refined assessment presents the ecological risks posed by the use of the herbicide atrazine. Based on the results from hundreds of toxicity studies on the effects of atrazine on plants and animals, over 20 years of surface water monitoring data, and higher tier aquatic exposure models, this risk assessment concludes that aquatic plant communities are impacted in many areas where atrazine use is heaviest, and there is potential chronic risk to fish, amphibians, and aquatic invertebrates in these same locations. In the terrestrial environment, there are risk concerns for mammals, birds, reptiles, plants and plant communities across the country for many of the atrazine uses. EPA levels of concern for chronic risk are exceeded by as much as 22, 198, and 62 times for birds, mammals, and fish, respectively. For aquatic phase amphibians, a weight of evidence analysis concluded there is potential for chronic risks to amphibians based on multiple effects endpoint concentrations compared to measured and predicted surface water concentrations. The breadth of terrestrial plant species and families potentially impacted by atrazine use at current labeled rates, as well as reduced rates of 0.5 and 0.25 lbs. a.i./A, suggest that terrestrial plant biodiversity and communities are likely to be impacted from off-field exposures via runoff and spray drift. Average atrazine concentrations in water at or above 5 μg/L for several weeks are predicted to lead to reproductive effects in fish, while a 60-day average of 3.4 μg/L has a high probability of impacting aquatic plant community primary productivity, structure and function.


View the PDF of the memorandum and cover sheet of EPA’s Refined Ecological Risk Assessment for Atrazine (later removed from EPA’s website)

Atrazine Registration Review

This is part of EPA’s 15 year review cycle for all pesticide active ingredients

It involves:

  • Ecological Assessments – including Endangered Species
  • Human Health Assessments – dietary (including drinking water), residential, occupational and cumulative
  • Review Tolerances
  • Label clarification


Phase I: Docket Opening

  • Docket Opens – June 26, 2013
  • Preliminary Work plan
  • Preliminary Assessments, Uses, Incidents, etc.
  • 60-day Public Comment Period – ended Aug 26, 2013 – over 55,000 comments


Phase II: Development

  • 60-day Public Comment Period – Inputs on draft risk assessment


Phase III: Final Decision

  • 60-day Public Comment Period – Inputs on changes, data needs
  • Final Decision – 2016?