Safety zone size
n. The area of a circular safety zone just large enough to protect firefighting personnel from radiant heat injury.
Safety zone size is an output computed in the BehavePlus fire modeling system based on the Butler and Cohen (1998) safety zone model. Personnel occupy a safe area at the center of the safety zone. The distance from the edge of the safe area to the fire is the separation distance. Safety zone size includes the safe area and the area between the safe area and the fire.
Although the region between the safe area and the fire is included in the safety zone size calculation, that area does not meet the definition of a safety zone because personnel are at risk of radiant heat injury.