What is the difference between a product's preharvest interval (PHI) and restricted-entry interval (REI)?

• A. PHI is the minimum time after application before harvest; REI is the minimum time before workers can re-enter the treated area.
• B. PHI is how long you must wait before applying again; REI is the same as PHI.
• C. PHI applies to workers safety; REI applies to equipment maintenance.
• D. PHI is the maximum time before harvest; REI is the maximum time before re-entry.

Answer: (A)

PHI tells you the minimum time that must pass between applying a pesticide and harvesting the treated crop, to ensure residues are within safe limits for consumers. REI, on the other hand, is the minimum time after application that workers must stay out of the treated area to avoid exposure. They’re different because PHI focuses on harvest timing and residue safety, while REI focuses on protecting workers from pesticide exposure.

So the correct idea is that PHI is about harvest timing, and REI is about when people can enter the treated area. The other statements mix up these roles or describe PHI/REI inaccurately:PHI is not about waiting to apply again, REI is not the same as PHI, PHI isn’t primarily about workers’ safety, PHI isn’t a maximum wait before harvest, and REI isn’t a maximum wait before re-entry.