Calculate pre-harvest interval and safe harvest date based on pesticide application date and product PHI requirements.
Calculate pre-harvest interval and safe harvest date based on pesticide application date and product PHI requirements. Get instant, accurate results for your farm.
Enter pesticide application date, pre-harvest interval (PHI) in days (from pesticide label), and re-entry interval (REI) in hours (from label). Click calculate to see earliest safe harvest date, earliest safe re-entry date/time, and days remaining until safe harvest.
The pesticide safety interval calculator helps you determine safe harvest dates and re-entry times after pesticide application. It calculates the pre-harvest interval (PHI) — the minimum days between last application and harvest — and the re-entry interval (REI) — when workers can safely re-enter treated areas. Compliance protects consumers and workers from pesticide exposure.
A: PHI (Pre-Harvest Interval) is the minimum number of days between the last pesticide application and harvest, designed to ensure pesticide residues in/on the harvested product are below legal tolerance levels. REI (Re-Entry Interval) is the minimum time (usually in hours) after application before workers can enter the treated area without protective equipment, designed to protect workers from acute exposure. PHI protects consumers; REI protects workers. Both are specified on the pesticide label and are legally binding.
A: The PHI is always printed on the pesticide label, under "Directions for Use" or "Pre-Harvest Interval." PHI varies by: pesticide active ingredient, crop type, application method (foliar vs. soil), and dose rate. The same pesticide may have different PHIs for different crops (e.g., 7 days for lettuce, 14 days for tomatoes, 30 days for apples). Always check the label for the specific crop you are treating. If the label does not list your crop, the pesticide is not registered for that use and applying it is illegal.
A: Harvesting before the PHI expires can result in: pesticide residues exceeding legal tolerances (making the product illegal to sell), rejection of shipments by buyers or regulatory agencies, food safety violations and potential legal liability, harm to consumers (especially vulnerable groups like children and pregnant women), and loss of organic certification (if applicable). Always use this calculator to plan applications so that the PHI expires before your planned harvest date. If you accidentally apply too close to harvest, contact your local agricultural extension or regulatory agency for guidance — do not sell the crop until residues are confirmed safe through testing.