What immediate actions should be taken if a fire occurs in the lab?

In the event of a fire in the lab, the most appropriate and safe immediate action is to activate the nearest fire alarm and evacuate the area. This response is crucial for ensuring personal safety and for alerting others in the vicinity about the emergency. Activating the fire alarm not only triggers an evacuation protocol but also notifies emergency services to respond to the fire promptly, which is essential in minimizing damage and ensuring the safety of everyone in the building.

Evacuating the area removes individuals from potential harm, allowing them to reach safety away from the danger. Laboratory environments can have hazardous materials and equipment, making immediate evacuation even more critical to prevent injuries or exacerbate the fire.

The other options present actions that can lead to further hazards. Throwing water on certain types of fires, particularly those involving flammable liquids or electrical components, can worsen the situation by causing the fire to spread. Continuing to work until the fire is out ignores personal safety and the potential for the fire to escalate. Closing the door and ignoring the situation fails to address the threat and does not alert others, which could endanger more individuals.