Is it scientifically possible for a human to spontaneously combust?

Spontaneous human combustion might seem to be little more than a convenient novel plot device, but the question about whether it can actually happen in real life is disputed.

Spontaneous human combustion is the process of a living human suddenly lighting itself on fire without an external source. The most recent reported case of this happening was in 2010, when Irish coroner Dr Ciaran McLoughlin declared that Michael Faherty had spontaneously combusted and burned to death in his own home.

He declared: “This fire was thoroughly investigated and I’m left with the conclusion that this fits into the category of spontaneous human combustion, for which there is no adequate explanation.” It has also featured in a variety of fictional media, notably Charles Dickens’ Bleak House, where alcoholic landlord Krook is reduced to ashes by an unsourced fire. This fictional account is based on Dickens’ belief that spontaneous combustion is possible, which he alleged was proven by multiple real-life reports.

Well, spontaneous combustion is a real phenomenon beyond the fictional world. Specific extremely flammable chemicals and materials, such as phosphorus and hay respectively, can light up at low ambient temperatures despite not having an ignition source

Dickens was referring to the reported dozens, and possibly hundreds, of cases of death by spontaneous human combustion between the 17^th and 19^th century that were hugely popular sources of debate and discussion at the time, often being overtly sensationalised by the media  to advance moral views on certain lifestyle choices.

A majority of the reported victims were older overweight women, often believed to be heavy drinkers as alcohol was found at the scene frequently. The victims’ bodies were said to have been heavily dismembered, with the torso completely burned away and puddles of dark, greasy substances left behind. Yet despite the severity of these burns, the immediate surroundings of the bodies were always reported as being entirely unaffected. So, how is this the case? Did they really spontaneously combust?

Well, spontaneous combustion is a real phenomenon beyond the fictional world. Specific extremely flammable chemicals and materials, such as phosphorus and hay respectively, can light up at low ambient temperatures despite not having an ignition source. Exothermic chemical reactions and heat accumulated from decaying organic matter and fermentation are the cause of these seemingly inexplicable fires, which is why they often occur at composting and mulching facilities.

However, this is not the case for human bodies, in which spontaneous combustion is largely deemed to be impossible. Roger Byard, a pathologist at the University of Adelaide, stated: “The reality is that people combust – but not spontaneously. If people could spontaneously burst into flames, you’d be down at Walmart and suddenly the little old lady beside you, pushing a trolley would explode.” His explanation for it, and one which is commonly accepted in the scientific community, is that humans combust because of the ‘wick effect’.

If a sleeping or intoxicated person spilled alcohol on themselves before catching a stray ember from a fireplace or a cigarette, their fat would begin to burn their insides and their clothes, much like a candle wick, would keep the flame alight

The wick effect involves people’s bodies effectively functioning like ‘human candles’. Human fat burns under blankets and thick clothing, being lit by small traces of accelerant, such as spilled liquor, and when ignited by sparks or even embers. Under these conditions, a fire produces hot temperatures by burning low and slow and causing little collateral damage. If a sleeping or intoxicated person spilled alcohol on themselves before catching a stray ember from a fireplace or a cigarette, their fat would begin to burn their insides and their clothes, much like a candle wick, would keep the flame alight.

As such, there is a level of comfort that comes with knowing that you won’t simply spontaneously combust at any given moment; however, it’s therefore important to remember not to accidentally burn yourself to death after an overly exciting time at Pop.