In the event of a suspected contamination, what should personnel do first?

Stopping all work immediately is the most prudent response in the event of suspected contamination. This action is essential for ensuring the safety of all personnel in the vicinity. By ceasing all activities, it minimizes the potential spread of contamination and allows for a controlled investigation of the situation.

When work is halted, personnel can assess the situation without potentially putting themselves or others at greater risk of exposure. This immediate containment is a critical step in a safe response to any incidents involving radiological materials.

Once all work has stopped, further actions can be taken, such as confirming contamination or notifying others, but it is vital to first secure the environment to prevent exacerbating potential contamination or exposure.