What is a requirement for posting warning signs related to REIs?

The correct answer highlights an important aspect of agricultural safety regarding Restricted Entry Intervals (REIs). Warning signs play a critical role in communicating potential hazards associated with pesticide applications to workers and the public.

When pesticides are applied, there is often a designated REI, which is a specified period during which entry to the treated area is restricted to protect individuals from exposure to the chemical residues that may still be present. The requirement to keep warning signs posted until the REI expires is essential to ensure that the area remains clearly marked as hazardous until it is safe for workers to re-enter. This helps prevent accidental exposure and enhances workplace safety by providing a visual cue that alerts individuals about the status of the pesticide application.

The options suggesting immediate removal after application or whether the signs should stay only until or for days after application do not align with the primary objective of ensuring a safe environment until the potential risk has fully dissipated. Keeping the signs up until the REI expires is essential, as it continuously informs and reminds individuals of the precautions necessary during that critical period.