When must REI no entry signs be posted?

The correct response signifies that no entry signs for Restricted Entry Interval (REI) must be posted when the REI is greater than 48 hours. This regulation is crucial for ensuring the safety of individuals who might enter treated areas after pesticide application. The REI is the period following a pesticide application during which entry into the treated area is restricted to protect human health from potential pesticide exposure.

Posting no entry signs serves as a clear visual indication to anyone in the vicinity that they should not enter the area until it is safe to do so. In situations where the REI is longer than 48 hours, the risks associated with residual pesticide presence can be significant, necessitating this additional precaution.

The other options would not be appropriate in this context. For instance, although signs may be advisable during all pesticide applications, it is specifically the duration of the REI that dictates the requirement for posted signs. The presence of pesticide handlers is also a crucial factor; however, it does not directly align with the requirement for no entry signage related to REI durations. Lastly, the notion of posting signs only on weekends does not take into account the non-discriminatory nature of pesticide safety regardless of the day of the week, which could endanger individuals present in the area