What is a Pre-Harvest Interval (PHI)?

A Pre-Harvest Interval (PHI) is the minimum number of days that must pass between the last pesticide application and crop harvest. It is listed on every pesticide product label and is legally binding. Violating the PHI can result in crop seizure, fines, and residue violations.

What is a Restricted Entry Interval (REI)?

A Restricted Entry Interval (REI) is the minimum time after a pesticide application before workers can re-enter the treated area without full protective equipment. REIs are measured in hours and are listed on the product label. Common REIs range from 4 to 48 hours.

Where do I find PHI and REI values?

PHI and REI values are found on the pesticide product label under the "Agricultural Use Requirements" or "Directions for Use" section. Always read the label for the specific product and crop combination you are using. Labels are the law.

Can I enter the field during the REI period?

Workers may only enter a treated area during the REI if they wear the full personal protective equipment (PPE) specified on the label, and only for limited early-entry tasks as allowed by regulation. Consult your state or regional pesticide authority for specific rules.

Does this calculator replace reading the product label?

No. This calculator is a convenience tool only. You must always read and follow the complete product label. The label is a legal document. If there is any discrepancy, the label takes precedence. Consult a licensed pest control advisor for site-specific guidance.

PHI/REI Calculator

The PHI/REI Calculator computes the earliest safe harvest date and earliest safe re-entry time after a pesticide application. Enter your spray completion date/time, the Pre-Harvest Interval (PHI) in days from the product label, and the Restricted Entry Interval (REI) in hours. The tool instantly returns both deadline dates so you can protect workers and ensure harvest compliance.

Enter Application Details

Spray Completion Date & Time

When was the spray application completed?

PHI (Pre-Harvest Interval) — Days

From the product label. Measured in days.

REI (Restricted Entry Interval) — Hours

From the product label. Measured in hours.

Results

Enter your spray details to calculate PHI and REI intervals

Important Safety Disclaimer

This tool is for informational and planning purposes only. Always read and follow the complete product label before any pesticide application. The label is a legal document and takes precedence over any calculator output. Consult a licensed Pest Control Advisor (PCA) for site-specific recommendations. VitiScribe is not responsible for decisions made based on this tool.

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