Which statement about positive pressure ventilation is true?

Positive pressure ventilation (PPV) is a technique used to control the movement of smoke and heat during a fire incident. The statement about PPV being true is that it should be used only if attack crews have access to all fire. This is critical because the effectiveness of PPV relies on the ability to manage the fire and remove smoke and heat from areas that are occupied or affected by the fire.

Using PPV when attack crews do not have full access to the fire can lead to unintended consequences, such as allowing the fire to spread more rapidly or creating conditions that are hazardous for both firefighters and civilians. Without the proper coordination between attack crews and ventilation efforts, it can result in backdraft conditions or a sudden increase in fire behavior, putting everyone at increased risk. Therefore, ensuring that all fire is accessible before implementing PPV is essential for the safety and effectiveness of firefighting operations.