Which are the prescribed shapes of the recommended initial isolation action zones?

• A. A square for the initial isolation zone with a rectangle downwind side for the protective action zone
• B. Two overlapping circles for both zones
• C. A triangle for isolation and a circle for protective action
• D. A circle for the initial isolation zone with an elongation of it downwind side for the protective action zone

Answer: (D)

In hazmat response, zones around a released hazard are drawn to reflect how the plume is expected to move with the wind. The initial isolation zone is placed close to the source to prevent entry and limit exposure. The protective action zone is then drawn elongated downwind to cover the area where the plume could travel, accounting for dispersion with weather conditions. This shape—circular around the source for isolation, with an elongated extension downwind for protection—matches how plumes actually move.

So the best choice describes a circle for the initial isolation zone and an elongated downwind extension for the protective action zone, aligning with plume travel guidance. The other options rely on shapes (square, triangle, overlapping circles) that don’t reflect how a hazardous plume travels with the wind, or treat both zones with the same shape, which isn’t consistent with dispersion patterns.