Which are the prescribed shapes of the initial isolation and protective action zones?

The correct shape for the initial isolation zone as prescribed is a circle, reflecting a uniform and immediate boundary surrounding the hazardous area where exposure risk is managed. The protective action zone, which extends outward from this isolation zone, often takes on an elongated shape toward the downwind side. This elongation is a critical safety measure, as it recognizes that many hazardous materials can disperse in the air, following the direction of the wind. By prioritizing the downwind direction, responders can maximize safety by ensuring that individuals are moved away from areas of potential exposure effectively.

The rationale behind this design is rooted in the behavior of hazardous materials during a release scenario—containing the area immediately surrounding the incident and extending protections based on environmental factors like wind direction.

The other options present shapes or orientations that do not align with standard practices. For instance, options that suggest elongation toward the upwind side or favoring rectangles or squares do not accurately represent the standard protocols for managing isolated and protective action zones during a hazardous materials incident. These standards have been developed from comprehensive data about how hazardous materials behave, ensuring that area protection measures are most effective and aligned with safety protocols.