Explain the term 're-entry interval' (REI) and how it affects on-site operations.

• A. The time after application during which workers can re-enter the treated area only after the product has dried.
• B. The time after application during which workers cannot re-enter the treated area without protective equipment.
• C. The time required for pesticides to degrade to zero.
• D. The duration of the entire pesticide label validity.

Answer: (B)

Re-entry interval is the safety window defined by the pesticide label that dictates how long you must wait after application before workers can enter the treated area without protective clothing and equipment. This interval controls on-site operations by shaping when entry is allowed and what PPE is required if entry is needed during that time. In practice, you plan jobs so that entry to treated areas happens after the REI has elapsed, or, if entry is necessary during the interval, workers must wear the PPE specified on the label. It’s not about how long the product takes to dry, how long pesticides take to degrade to zero, or how long the label stays valid; it’s specifically about protecting workers from exposure during the period immediately after application.