Which action confirms you have stopped the source of a hazmat release?

Which action confirms you have stopped the source of a hazmat release?

• A. Ventilating the area to dilute vapors.
• B. Isolating or shutting off the source, such as closing a valve or sealing the container.
• C. Moving the container away from people.
• D. Requesting additional resources.

Answer: (B)

The action that stops a hazmat release is isolating the source—shutting off the flow, closing valves, or sealing the container—so no more material can escape. This directly halts the release at its origin, which is the primary way to stabilize the scene. Ventilating the area may reduce concentration, but it does not stop the source and can spread vapors to new areas. Moving the container away protects people from exposure, but the release itself continues until the source is secured. Requesting additional resources is important for incident management, but it does not stop the release.