Avoiding Herbicide, Pesticide Overspray

Farmers and ranchers know that use of chemicals in agriculture, including pesticides and herbicides, is challenging. Whether they are applied as dust or in liquid form, they require special handling. Adding to the difficulty, even the most rigorously managed application program is subject to one force outside anyone’s control: the weather.

That means drift — also known as overspray — can pose a problem. It typically happens when strong winds sweep in as agricultural chemicals are being applied, carrying them into areas where they’re not wanted. Drift can also come from many other sources, including vegetable patches, lawn care applications, right-of-way or commercial green spaces, efforts to control weeds in parks and on public lands, runoff into farm ponds and lakes, or even due to actions by homeowners trying to control weeds in their yards. Whether these chemicals are applied via spray arms on machinery, by crop dusting airplanes, or by individuals using hand-sprayers, it can be difficult to confine their application only to the target area.

Real consequences

The U.S. Environmental Protection Agency says drift effects are potentially long-lasting: the chemical you apply today could impact crop health years from now.

There can be legal ramifications, too. According to a September 2025 article by the Penn State Extension service, “If you cause a substantial amount of drift-related damage, you may get a call from the Department of Agriculture or potentially even a lawyer. It is likely that you would not even know that you caused the damage until someone knocks on your door. The most important thing to remember is that you (the applicator) are responsible for pesticide drift, even if environmental conditions are the cause.”

Strategies for mitigation

Drift can be diminished if you alter your practices and make some changes to your equipment. Here are a few guidelines:

• Get licensed. Most jurisdictions require pesticides to be applied by licensed applicators. To get this designation, a would-be applicator has to be trained in applying the chemicals and preventing them from ending up where they’re not wanted.
• Read the label or visit the website. Each product will have specific requirements, and it’s your responsibility to know them and apply them according to the label.
• Manage your mix. Be sure you carefully monitor the concentration of your chemicals, and with herbicides, always use EPA-approved tank-mix partners, as some are known to contribute to drift.
• Get the lay of the land. Familiarity with properties adjacent to yours should be part of your safe-handling plan. It’s important to know what type of crops are growing in proximity to your fields, especially downwind of wherever you’ll be applying the chemicals. You should also know if there are beehives in your area, as bees are very sensitive to environmental contaminants. FieldWatch.com, a non-profit crop registry, may be able to give you this information.
• Communicate. You should notify neighboring farmers and ranchers where and what you’ll be spraying. Not only will this give them fair warning, it will also encourage them to return the favor.
• It’s about more than wind. Wind conditions are important, of course. You should avoid applying chemicals when wind speed is less than 3 miles per hour or greater than 10 miles per hour. But other environmental factors such as temperature and humidity may have a bearing on what you do. For example, high temperatures and low humidity can increase the chances of drift.
• It’s not just what you spray, it’s how you spray it. You should calibrate your equipment to ensure you’re using the proper application rate and be sure your equipment has the right size applicator nozzle for the chemical you’ll be applying. Some nozzles produce different size droplets, or even fog, which may promote drift. The pressure at which you’re spraying is also important, as is the spray pattern.
• Slow your roll. Do not exceed guidelines for the speed at which you apply chemicals.
• Wash up. If you’ve been in proximity to pesticides or herbicides as they’re being applied, it’s important to avoid secondary contamination. After you’re done, put your contaminated clothing in the wash right away, and take an immediate shower.
• Know the signs. Symptoms of exposure to herbicide or pesticide include:
  1. Difficulty breathing or irritation of your eyes, nose or throat;
  2. Skin irritation or rash;
  3. Headache;
  4. Stomachache or diarrhea.

Any of these symptoms, either alone or in combination, could indicate you’ve been exposed. Don’t just ascribe your symptoms to a cold or the flu; better safe than sorry. If you think you or anyone else associated with your farming or ranching operations has been exposed to herbicide or pesticide, seek help with a medical professional immediately.

Sources: Whitaker Marketing Group; Minnesota Department of Agriculture

The information included here was obtained from sources believed to be reliable, however Grinnell Mutual Reinsurance Company, SI, and its employees make no guarantee of results and assume no liability in connection with any training, materials, suggestions, or information provided. It is the user’s responsibility to confirm compliance with any applicable local, state, or federal regulations. Information obtained from or via Grinnell Mutual Reinsurance Company, SI, should not be used as the basis for legal advice and should be confirmed with alternative sources.

1/2026