What is crucial to prevent further harm from chemical spills?

Establishing a containment barrier is essential in preventing further harm from chemical spills because it helps to contain the hazardous material within a defined area, preventing it from spreading to other locations and minimizing exposure to people and the environment. Containment is the first step in managing a spill effectively, as it isolates the contamination and allows for a more controlled and safe cleanup process.

While monitoring air quality is important for assessing the level of exposure to harmful fumes or vapors, it does not directly prevent the spread of the chemical itself. Similarly, using water to dilute certain chemicals may be inappropriate or even hazardous, as it can sometimes react adversely with specific substances, potentially worsening the situation. Evacuating the area is a necessary safety measure but does not address the immediate need to contain the spill and prevent further damage. Therefore, the establishment of a containment barrier is the most critical and immediate action in managing a chemical spill effectively.