PHI/REI Calculator Guide

The PHI/REI Calculator helps you determine the earliest safe harvest date and earliest safe re-entry time after a pesticide application.

How to use it:

Enter the date and time your spray application was completed

Enter the Pre-Harvest Interval (PHI) in days from the product label

Enter the Restricted Entry Interval (REI) in hours from the product label

Click Calculate to see your results

Understanding your results:

Earliest Safe Harvest: The first date you can legally harvest the treated block

Earliest Safe Re-Entry: The first date/time workers can enter without full PPE

Remember: The product label is the law. If there's any discrepancy between this tool and the label, the label takes precedence.