Spontaneous (Human) Combustion

Spontaneous combustion is a process in which the substance start self-heating by internal reactions and or by reaction with oxygen in air which leads to thermal runaway and finally igniting itself.

Bacterial fermentation in hay can result in spontaneous combustion. Moist haystack may start self-heating and ignite itself.  There are many materials which can run into spontaneous combustion such as hay, charcoal, oil seeds, oily rags, pistachios etc.

English: A large compost pile can spontaneousl...
English: A large compost pile can spontaneously combust if not properly managed. Español: Una pila de compost grande puede arder espontáneamente si no se trata de forma adecuada. Deutsch: großer Komposthaufen nach der Selbstentzündung (Photo credit: Wikipedia)

Transport regulations classify substances liable to spontaneous combustion under Class 4.2. Model Regulations states “Self-heating of a substance is a process where the gradual reaction of that substance with oxygen (in air) generates heat. If the rate of heat production exceeds the rate of heat loss, then the temperature of the substance will rise which, after an induction time, may lead to self-ignition and combustion”

Label of Class 4.2 substances liable to spontaneous combustion
Label of Class 4.2 substances liable to spontaneous combustion

There are many reported cases of spontaneous human combustion. Some living or some recently dead burns without any external source of ignition. Though many studies were conducted on the possibility of such instances reported, there is so far no scientific reasoning or proof of spontaneous human combustion. Natural explanations include intestinal conversion of food into large quantity of methane or raised level of blood alcohol.

A boy named Rahul aged 3.5 months (in Tamilnadu, India) as of August 2013, is reported to be causing fire on his own almost 4 times since his birth.