Restricted Entry and Pre-Harvest Intervals Explained

A restricted-entry interval (REI) limits entry to a treated area after an application. A pre-harvest interval (PHI) is the label-specified time to wait before harvest. Record the product, crop/block, application date and time, and the label values; do not infer either interval from a product class or another crop’s directions.

For covered agricultural uses, the Worker Protection Standard requires employers to keep workers out of treated areas until the label-specified REI expires, subject only to the regulation’s specific exceptions.

Find the REI and any early-entry conditions in the Agricultural Use Requirements and directions on the current product labeling. Find the PHI in the directions for the exact crop and use pattern. If multiple products are applied at the same time, the Worker Protection Standard uses the longest applicable REI.

Record the application time, not only the date: REI is measured in hours. Track the PHI from the last relevant application as specified by the label. Use the Spray Application Rate Calculator before application, and retain the actual product and rate with the interval record.

Hours and days are label inputs, not defaults supplied by this guide. Use the recorded local application time and confirm the displayed date/time against the applicable label and local requirements.

A cleared REI concerns entry restrictions; it does not mean the PHI has cleared. A cleared PHI does not override any other label, worker-protection or market requirement. Post or communicate treated-area information and retain records required for the operation and jurisdiction; contact the label holder or regulator when the label or timing is unclear.

• The tracker adds the entered intervals to the entered time; it cannot validate a product label, crop registration or local rule.
• Early entry, greenhouse ventilation, multiple products and emergency situations may have additional legal conditions.
• PHI is crop- and use-specific; do not reuse one crop’s value for another.
• The calculator is a recordkeeping aid, not legal or safety advice.

• Recording only the application date and losing the REI’s hour-level timing.
• Using a generic interval table instead of the current label for the exact crop and use.
• Assuming an REI clearance permits harvest before the PHI clears.
• Failing to reassess the record after a later application.

40 CFR Part 170 — Worker Protection Standard defines an REI and sets entry restrictions, including the longest applicable interval for simultaneous applications. EPA’s Introduction to Pesticide Labels explains that directions and precautions on a label define the permitted use.