What should be the immediate response after noticing a persistent hazardous gas leak?

The immediate response to a persistent hazardous gas leak should be to evacuate the area. This action is crucial for ensuring the safety of personnel nearby, as hazardous gas leaks can pose significant risks, including inhalation exposure, explosion, or fire hazards. Evacuation helps to minimize the number of people potentially affected by the leak and provides a clear path for emergency responders to address the situation appropriately.

While sealing off the affected area and reporting to the control center are important follow-up actions, they should occur after ensuring that all personnel are safely evacuated. Investigating the source of the leak poses unnecessary risks to individuals in the area during the initial response phase, where safety takes precedence.