When a liquid accelerant is poured onto a floor and spatters or runs in finger patterns. When ignited, it will burn in this pattern. The ignition and subsequent combustion of a flammable or combustible liquid inadvertently released from a container. The first onset of burning or fire in a combustible material which has been heated without external heat. The minimum temperature at which the self-heating properties of a substance can lead to ignition.
Variations can occur due to specimen size, rate of heat loss, moisture content, etc.
Electric timers, hair dryers, clocks, light bulbs and other devices are typical. When there is one or more probable fire causes, but none are conclusive. The highest percentage of concentration by volume of flammable vapour mixed with air which will bum with a flame. Also, one which has developed because of a secondary fire.