A flashover is the near simultaneous ignition of all combustible material in an enclosed area. This ignition includes the combustible contents of the room along with the buildup of  combustible gasses. Flashover typically occurs between 900-1,000 degrees fahrenheit. Flashover poses a very serious threat to firefighters. Firefighters can’t survive for more than about 2 seconds in a room that flashes over even with protective gear on. Many firefighters have lost their life due to flash over. There are many indicators of flashover such as a rapid buildup of heat, thick dark black smoke, and rollover. Flashover simulators help firefighters learn these precursors of a flashover so they will know to get out before one occurs.

The following video was captured on a helmet camera from inside a flashover simulator. Towards the end of the video, some examples of rollover are shown. Rollover is one of the most reliable indicators of a flashover and is defined as a condition where the unburned fire gases accumulated at the top of the compartment ignite and flames propagate through the hot gas layer.

Flashover Video click here