Restricted Entry Interval (REI)

Last updated: November 22, 2021

What Does Restricted Entry Interval (REI) Mean?

The term restricted entry interval (REI) is an indicator of the time immediately after a pesticide application when a person or worker can safely re-enter the premises.

All pesticides are different and feature different REI time frames. Some types of pesticides have a 12-hour REI, but others are different. REI times are dependent on the type of pesticide used, the crop, the method of pesticide application, and any post-application methods that may have been utilized.

If two or more pesticides have been used simultaneously, then whichever pesticide has the longer REI time requirements must be followed to help ensure safety.


Maximum Yield Explains Restricted Entry Interval (REI)

Restricted entry interval (REI) is also known as the re-entry interval or the re-entry time.

REI’s are set to protect people and animals from the potentially harmful effects of pesticide exposure or poisoning. If a person enters the region where pesticides have been applied too soon, they risk having the pesticide inadvertently transferred to their skin. The soil’s surface dust that is laced with the pesticide might also fly up onto the person’s body, into their eyes, or be inhaled. Moist droplets and pesticide dust on a plant’s leaves can also become airborne in the wind.

Some pesticides also become vapor, which may be harmful if inhaled. Many factors influence the restricted entry interval for the pesticide product being used, such as its toxicity, formulation, weather conditions, characteristic of the specific pesticide, and application rate/method. The label on most pesticides contains restricted entry interval requirements for the specific product.

Organic pesticides generally have a shorter REI time frame than their synthetic chemical counterparts, but not always. One way to avoid worrying about REI at all is to choose biocontrol pest options, which includes preventative measures, sticky traps, screens, and integrated pest management (IPM).


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