The EPA, Endangered Species Act, and ensuring compliance for pesticide applications

By Alyssa Essman

What is the Endangered Species Act, and why am I hearing more about it now?

The Endangered Species Act (ESA) was passed by Congress in 1973 to protect species classified as endangered and their critical habitat. The Environmental Protection Agency (EPA) is responsible for ensuring the use of pesticides doesn’t harm endangered species or habitats via the pesticide registration process. In response to recent litigation, the EPA finalized new frameworks (called “strategies”) for pesticide labeling that seek to address this issue for the mitigation of off-target movement of pesticides, namely, spray drift, runoff, and erosion. The herbicide strategy was finalized in August 2024, and the insecticide strategy was finalized in April 2025. These frameworks will be used to create new guidelines on product labels as they are registered, or as existing products work through the reregistration process. This may include a description of the mitigation measures needed to reduce off-target movement, and/or the number of runoff mitigation points that need to be achieved using associated mitigation measures. According to the Ohio Department of Natural Resources, as of September 2024, there are 132 endangered species in Ohio, the majority of which are fish, mollusks, or dragonflies.

How will this influence pesticide applications?

Product labels will be created or updated to include guidance related to the ESA during the registration process, or as products go through the reregistration process, which takes place about every 15 years. When these mitigation measures are required anywhere the pesticide is to be used, they will be listed directly on the product label. Where a mitigation measure is only required in certain areas, called Pesticide Use Limitation Areas (PULAs), based on the location and presence of endangered species, they will be listed on the EPA’s Bulletins Live! Two website.

When and where do I check for application requirements?

There will now be two places to look for pesticide application requirements. The first is the product label. On the product label, any listed mitigation measures will be required anywhere the product is used, regardless of location or proximity to endangered species. There will be a section on the label designated to list any specific requirements for preventing off-target movement from spray drift, runoff, or erosion. These sections may list management practices, such as wind speed limitations or buffer size, and/or designate the number of runoff mitigation points needed for a given product to be used. Runoff relief points are available based on location and the likelihood of runoff. Ohio counties automatically have two or three points based on the county where the application will be made (Figure 1).

Figure 1. Runoff Vulnerability Mitigation Relief Points in Ohio by County.

The first herbicide product registered with labeling following this framework was Liberty Ultra (BASF). The herbicide label lists the following for spray drift mitigation, required anywhere the product is used:

• Wind speed and direction must be measured on location.
• Sustained wind speed must be between 3 and 15 MPH, measured at the release height or higher, in an area free from obstructions.
• Mandatory 10 ft downwind spray buffer for ground application, reduced to 0 ft if:

Using a drift-reducing adjuvant, using a hooded sprayer, a windbreak, or a shelterbelt is present.

It also states that three runoff mitigation points are required for a given field. As stated above, counties in Ohio already have two or three points based on runoff vulnerability. The EPA is also assigning one point for any applicator who tracks mitigations on paper or in electronic format. This means that just for being in Ohio and keeping track of mitigations, the 3 points required for the application are easily achieved for applications of Liberty Ultra

Who is responsible for ensuring compliance?

Ultimately, it is the responsibility of pesticide applicators to ensure compliance via product labels and the Bulletins Live! Two website. The website must be checked within 6 months up to the day of application. This means that for planned applications, compliance can be checked and records saved well in advance of the busy growing season.

Formal complaints are always a possible outcome of off-target movement events that cause damage to crops or other desirable vegetation. Saving output from the EPA’s mitigation calculator showing management practices, application procedures, and field characteristics that result in a field’s total point output is not required, but highly recommended. This ensures that, in the event of an off-target movement event that leads to a complaint, compliance can be easily verified.

What should I do to ensure I’m in compliance?

1. Check the pesticide label for any mandatory spray drift mitigations and runoff mitigation measures, as well as the number of points needed for an application.
2. Calculate the total number of points achieved for a given field using the EPA’s mitigation calculator (www.epa.gov/pesticides/runofferosion-mitigation-calculator; use of the Google Chrome browser is recommended). Determine whether sufficient points have been achieved, and if not, what mitigation measure options are available.
3. Check Bulletins Live! Two within six months of herbicide application (www.epa.gov/endangered-species/bulletins-live-two-view-bulletins) and review to determine if additional mitigation measures are required.
4. Save results for records in a printed or electronic format. This step is not required but recommended to ensure compliance can be verified.

For a more comprehensive checklist, visit ohioline.osu.edu/factsheet/anr-0222. More resources related to this topic can be found at u.osu.edu/osuweeds/multimedia/endangered-species-act/