Which of the following is NOT a principle of ventilation?

The principle of ventilation focuses on techniques and strategies in firefighting that aim to control heat and smoke during a fire incident. While personal safety is critically important in overall fire operations, it is not classified as a direct principle of ventilation.

Vent for personal safety does not specifically address the goals of ventilation itself, which primarily aim to enhance firefighting effectiveness and minimize property damage. The other principles mentioned — fire containment, property conservation, and life safety — directly relate to managing the environment within a structure experiencing a fire. Firefighting strategies typically prioritize these principles to ensure that the operation is effective in controlling the fire's spread, protecting lives, and preserving property. Thus, while personal safety is an overarching concern, it does not fall under the specific framework of ventilation principles.