An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Label Review Training: Module 3: Special Issues, Page 27

Section 6: How should I review worker protection labeling?

Determining Restricted Entry Intervals

The correct REI may be specified in the regulatory assessment document. If a regulatory assessment document is not available, refer to Supplement Three-A of Pesticide Registration (PR) Notice 93-7, or use the following guidance to determine the correct REI.

To determine REIs, follow the steps below, but be sure to also check any RED or registration review documents to determine if a specific REI was set on a case-by-case basis for this chemical.

Step 1: Identify acute toxicity data to be used in determining REIs

REIs are based on the most severe acute toxicity category assigned to the acute dermal, eye irritation, and skin irritation data for all of the active ingredients in a product. In many instances, these data are not always available. Refer to Chapter 10, Section VII.C of the Label Review Manual for a list indicating the preferred order for selecting data with which to determine the toxicity category for each active ingredient.

Step 2: Determine appropriate REI(s) using the chart below

Most Severe Toxicity Category Used to Determine the REI Length of Required REI
If the most severe toxicity category is III or IV... The REI is 12 hours
If the most severe toxicity category is II... The REI is 24 hours
If the most severe toxicity category is I... The REI is 48 hours
In addition:
If the product is an organophosphate ester that inhibits cholinesterase and may be applied outdoors in an area where the average rainfall for the application site is less than 25 inches per year.
The REI is 72 hours


For more information about REIs, see Chapter 10, Section VIII of the Label Review Manual or Supplement Three-A of PR Notice 93-7.

Page 27 and 43
Previous Page   Next Page