The incipient stage of fire growth begins with ignition, after which the fire can take one of two paths: self-extinguishment or continued growth. If it consumes the readily available fuel or if it remains small enough that it cannot produce enough fuel vapour to continue burning, then it will self-extinguish.

This can happen when items contain high levels of fire retardant additives, or when only one item is burning and any other fuel packages are located too far away for radiant ignition to occur and continue to provide the fuel needed to sustain combustion.

Another way a fire may self-extinguish is if it runs out of air while growing and continues to lack sufficient air until the enclosure and all of the fuel in the enclosure cool down sufficiently that the fire is completely extinguished. In either situation, if the fire self-extinguishes soon after ignition, as shown in Figure 3, then it will leave minimal damage.