Preharvest Interval

The preharvest interval (PHI) is the wait time between a pesticide application and when a crop can be harvested. The label will state how long the crop must remain in the garden or field after spraying. During the PHI, the pesticide may be broken down in the plant, or on its surface. Sun, rain, and warm temperatures may affect how quickly this happens.

• Following the PHI reduces your risk from using pesticides on food.
• If your fruit or vegetable is not listed on the label, that means you cannot apply the product to it.
• Harvesting a crop before the PHI is illegal. The time listed on the label has been tested to minimize pesticide residue.
• Wait times for the same fruit or vegetable can differ between products.
• For products that can be applied up to the day of harvest, the label may list '0' (zero) days, or there may be no time listed.
• The EPA sets limits on residue levels, called tolerances, for every pesticide on each crop. The PHI helps meet these safety standards.
• If you sell your produce and you do not follow the PHI, there is a risk of too much pesticide residue on them. Residues above legal limits can keep a crop from sale or export.
• Always follow the label, including how and when to apply, and the PHI.

Additional Resources:

• Check Labels for Pre-harvest Intervals - Michigan State University
• Harvest Is... - Colorado State Extension
• Respecting Preharvest and Restricted Entry Intervals: A Question of Common Sense! - Health Canada
• Farm Basics: Pre-Harvest Interval (video) - Ag PhD

If you have questions about this, or any pesticide-related topic, please call NPIC at 800-858-7378 (8:00am - 12:00pm PST), or email us at npic@ace.orst.edu.