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Guide outlines steps to take when pesticide drift occurs

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URBANA, Ill. – Pesticides assist in managing pests. People should use precise application techniques detailed on the label so they don’t endanger people, pets, livestock, plants, and the environment.

Damage can occur when pesticide drifts from its intended location onto adjacent fields and landscapes. Drift happens when pesticide spray particles and vapors escape from the intended target area.

A new guide available at helps producers and gardeners know what to do if pesticide drift is suspected. 

"While much work has been done to educate pesticide users about safety and most applications are made according to label directions, unfortunately cases of misuse still occur," says Michelle Wiesbrook, University of Illinois Extension weed science specialist. "The most common type of pesticide misuse is pesticide drift, and when it occurs, emotions can run high while seeking answers."

How drift occurs

There are two ways pesticides can be carried downwind to non-target areas: vapor drift and particle drift. Both types of drift should be considered when making an application, and steps should be taken to minimize their occurrence.

Vapor drift occurs when vapors produced by a pesticide are carried out of the target area. The process of vapor production, called volatilization, can occur up to several days after an application. The occurrence of vapor drift is sometimes difficult to predict and relies on weather conditions occurring after a pesticide application.

Particle drift is the actual movement of spray particles off target, usually by the wind. Particle drift results mostly from the smaller drops created in the spraying process. Wind speed and direction are major factors in determining if droplets are carried off target. Factors such as nozzle selection, spray pressure, height of the spray boom, and weather all play a role in particle drift.

Where to turn for help

The Illinois Department of Agriculture administers and enforces the pesticide laws. Illinois Extension provides educational, problem-solving, and mediating services. Extension administers several pesticide training courses to prepare people for required certifications.

"A proper diagnosis of pesticide drift requires quite a bit of problem solving to rule out any possible causes of injury such as disease or insect damage which can mimic chemical injury," says Wiesbrook. "Local Extension educators and state specialists may assist with this process."

The University of Illinois Plant Clinic also provides consultation. Submit plant samples or pictures and any relevant information as outlined at the website.

"The Plant Clinic does not perform any laboratory analysis to detect potential herbicide residues in plant or soil samples," Wiesbrook says. "Instead, staff examine samples and consult with university specialists to rule out other possible causes of the symptoms."

Suspected herbicide damage is noted on the laboratory report, along with a list of private laboratories clients can contact if they wish to pursue further private laboratory testing, Wiesbrook says.

Filing a complaint

To file a complaint, obtain a pesticide drift complaint form from IDOA’s Bureau of Environmental Programs at or call 800-641-3934 or 217-785-2427. Complaint forms must be received by the IDOA within 30 days of the incident or within 30 days of when the damage was noticed. No administrative action can be taken after that deadline.

The IDOA will visit the site and collect samples for analysis at the IDOA lab.

Access the guide

The new free guide provides more information on drift and serves as a navigation tool for those faced with potential drift injury challenges. Read the guide at

ABOUT EXTENSION: Illinois Extension leads public outreach for University of Illinois by translating research into action plans that allow Illinois families, businesses, and community leaders to solve problems, make informed decisions, and adapt to changes and opportunities.

SOURCE: Michelle Wiesbrook, Illinois Extension Weed Science Specialist
WRITER: Judy Mae Bingman, Illinois Extension Marketing and Communications Manager