Which of the following is NOT an indicator of imminent flashover?

• A. Smoke showing rollover
• B. Dense black smoke with rapid rise
• C. Steady, cool air pressure
• D. Fire involving multiple levels with changing color

Answer: (C)

Understanding imminent flashover comes from recognizing how the fire and smoke behave as conditions deteriorate. Signs like smoke rolling over and showing flames, dense black smoke that rises rapidly, and fire spreading through multiple levels with changing smoke color all point to extreme heat and unstable ventilation leading toward a flashover. A steady, cool air pressure, on the other hand, suggests there isn’t the rapid pressure change or heat buildup associated with that critical transition. In other words, the room isn’t displaying the turbulent movements and color shifts that accompany flashover, making steady, cool pressure not an indicator of it. So among typical warning signs, this calm, cool pressure stands in contrast to the others and is not an imminent-flashover cue.