Which of the following must be done immediately after decontamination?

Monitoring for residual contamination is essential immediately after decontamination because it ensures that all hazardous materials have been effectively removed from personnel and equipment. This step is crucial in confirming that there is no lingering contamination that could pose a risk to responders or the environment.

By conducting thorough monitoring, responders can assess the efficacy of the decontamination process and make informed decisions about the safety of allowing personnel to enter non-contaminated areas or to remove their protective equipment. This step helps to prevent secondary contamination and ensures the safety of all involved.

In contrast, while the evacuation of personnel, reapplying protective equipment, and documenting procedures are important components of overall safety and operational protocol, they come after confirming that the area and individuals are free from residual hazards. Thus, monitoring for residual contamination stands out as the immediate priority following decontamination.