Best Management Practices

The MDA, in cooperation with the University of Minnesota Extension and other interested parties, has developed voluntary best management practices (BMPs) to address the presence of chlorpyrifos in Minnesota’s surface water from normal agricultural use. The BMPs may also refer to mandatory label use requirements. Always read and follow product labels.


Application Setbacks

The label is the law. Treatment setbacks or buffer zones (distances that must exist to separate sensitive sites from the targeted application site) MUST be utilized for applications of products with mandatory label requirements. Setbacks are listed on most chlorpyrifos labels for water and sensitive sites where bystanders may visit.

Sensitive Sites

Due to the potential risk to human health, setbacks are required. Sensitive sites are areas where bystanders (especially children) may be located or visit. These include:

  • Residential lawns
  • Pedestrian sidewalks
  • Outdoor recreational areas, such as:
    • School grounds
    • Athletic fields
    • Parks
  • All property associated with buildings occupied by humans for residential or commercial purposes, for example:
    • Homes
    • Farmworker housing
    • Schools
    • Daycare centers
    • Nursing homes
    • Hospitals

Setback distances for liquid products are based on the application rate, nozzle droplet size, and method of application.

For sensitive sites, the application required setbacks (buffer zones) are as follows:

Application Rate
(lb ai/A)
Nozzle Droplet Size Aerial Setback
(feet)
Airblast Setback
(feet)
Ground Setback
(feet)
>0.5 - 1 coarse or very coarse 10 10 10
>0.5 - 1 medium 25 10 10
>1 - 2 coarse or very coarse 50 10 10
>1 - 2 medium 80 10 10
>2 - 3 coarse or very coarse 80 10 10
>2 - 3 medium 100 10 10
>3 - 4 medium or coarse NA* 25 10
>4 medium or coarse NA* 50 10

*NA is not allowed

Only pesticide handlers are permitted in the setback area during application of this product. Do not apply this product if anyone other than a mixer, loader, or applicator is in the setback area. This is an exception. Vehicles and persons riding bicycles that are passing through the setback area on public or private roadways are permitted.

Water

Applicators must also maintain the following application setbacks from surface water bodies while applying certain chlorpyrifos products near:

  • Natural ponds
  • Ditches (may require setbacks, determined on site-specific basis)
  • Marshes
  • Streams
  • Lakes and rivers

For water, the setback for each type of application is as follows:

  • Ground and chemigation: 25 feet
  • Aerial: 150 feet
  • Orchard airblast: 50 feet

Measurements for setbacks are made from the water body’s edge at the time of application. For further clarification of chlorpyrifos setbacks see the Chlorpyrifos Label Setbacks in Minnesota.

If the label requires a setback, the MDA suggests you demonstrate on your application records that the required setback was followed. We suggest using a figure or picture to show the setback, which provides evidence of compliance with the label. A few examples can be seen here.

Series of three images illustrating how to document application setback. The first is a drawing of a house and the 100 foot marking from the edge of the yard and a note of medium nozzle. Second image is an aerial image of a field and the 150 foot setback labeled. The third is a field with 66-foot setback from waterway.

 


Additional Label Requirements and Recommendations

In addition to setbacks, applications of some liquid products must occur:

  • Within 4 feet of the crop canopy or soil surface for ground applications
  • Within 10 feet of the crop canopy for aerial applications
  • Between 3 and 10 mph (wind speed)
  • After 24 hours following flood irrigation

Additional mandatory requirements may exist depending on the label.

Applicator Recommendations

Applicators who apply products containing chlorpyrifos are encouraged to get a blood test to establish their baseline readings of cholinesterase in their blood. With an established baseline, doctors can determine if illness following pesticide application could be due to chlorpyrifos. Proper use of personal protection equipment (PPE), especially respirators, as listed on the label is one way to prevent exposure when handling this chemical.