What measures must be taken if air/lead levels exceed the action level?

When air or lead levels exceed the action level, specific measures must be taken to ensure the safety and health of workers. The correct action in this scenario, which involves the closure of the job site if lead levels reach 50 µg/m³, is based on established safety regulations designed to mitigate hazardous conditions.

Closing the job site is an immediate response to protect workers from exposure to harmful levels of lead, which can have severe health consequences. This decisive measure prevents continued risk to employees and allows for an assessment of the situation, ensuring that corrective actions can be taken before reoccupying the area.

While other options such as continuously monitoring levels or increasing ventilation may be part of a broader safety protocol, they do not address the immediate need to protect worker health as effectively as closing the job site does. Informing employees of the hazard is also important, but the priority in a situation where action levels are exceeded is to eliminate the risk altogether by halting activities in that area.