Positive ventilation is primarily used to prevent the spread of what during a fire?

Positive ventilation is primarily used to prevent the spread of smoke during a fire. This technique involves introducing fresh air into a space, which helps to dilute and push out smoke, thereby reducing its concentration and improving visibility. Effective smoke management is crucial in fire situations, as smoke can be more hazardous than the fire itself, posing serious risks to firefighters and anyone trapped inside a structure.

By creating a pressure difference, positive ventilation can effectively channel the smoke out of the area, reducing the likelihood of smoke inhalation injuries and allowing for safer escape routes. This approach also assists in preventing the smoke from spreading to other parts of the building, thus aiding in controlling the overall situation during firefighting efforts.

In contrast, while heat, flames, and sparks are significant concerns during a fire, the primary focus of positive ventilation is on managing smoke. Reducing smoke circulation can improve conditions, ensuring a safer environment for both victims and first responders.