BURLINGTON, Colo. — What is a restricted pesticide re-entry interval?  This interval is the restricted-entry interval (REI) into a pesticide treated area.  In other words, when is it safe to walk into a pesticide treated area.  The REI can be different for each pesticide applied and crop applied.  Some pesticides list different REI’s depending on the crop, application method, or the post-application activity (are workers hand hoeing or working on machinery in a field).  Tank mixes occur when two or more pesticides are applied at the same time.  In this case, the pesticide with the longer REI must be followed.

How do we find a pesticide’s REI number?  All pesticides have a “label” listed on the container.  The label is the law.  The label contains important information such as what the pesticide is (the active ingredient), what the pesticide controls (which pests), how much pesticide to apply, and the Directions for Use section.  The Directions for Use section will list the REI for the intended use.  For many common pesticides the REI is 24 hours while some applications require 48 hours.  The REI is different for each pesticide, application and crop.  Always find a pesticide’s REI before entering into a treated area.  After a pesticide application’s REI has expired, the area is considered safe for re-entry.  REI’s for some of the typical pesticides used are 2,4-D 48 hours, Glyphosate 12 hours, Sevin garden insecticide 12 hours.

Source: www.epa.gov

–RF Meyer, Colorado State University Extension