How does spontaneous human combustion work? Is it possible?

Answer 1

The human body bursts into flame, spontaneous combustion, hardly likely as a human body is mostly water and can't burn until all that water is gone... by evaporation. The average human weighs 155 pounds and that's an awful lot of water to evaporate, requiring an awful lot of energy, so you're talking about extraterrestial science in the end to get an accident of this calibre.
Or you could stand within modest distance of the next nuclear test and burn baby burn.

Answer 2

It works the same as any other spontaneous combustion. All combustable materials (there's a lot of carbon in the human body v.good for combustion) have a autoignition temperature which is the temperature when they burn without the need for a flame. Diesel engines work in this way; they have no spark plugs, the fuel is pressurised until it has got hot enough to burn.

No it is not a myth and no it does not need "sustained" temperatures at least not for a while. and chucking someone in a bonfire is definitely not "spontaneous" combustion except in the figurative sense. A regular bonfire also wouldn't be hot enough.

I work with high powered UV lasers and occasionally leave my hand in the beam for longer than the half a second or so required for it burn me. Done it a few times but once when I pulled it out there was smoke coming off and it kept on getting stronger until I shook it out and headed for the sink. The laser beam gave a small but concentrated dose of energy that was enough to raise the temperature of my skin past the autoignition temperature in a very localised region.

So yeah no myth,... it's not very fun and it stank pretty bad, kinda like microwaved chicken.

edit: By the way I'd be interested in knowing what the autoignition temperature of skin is, someone wrote 500F. I don't know exactly what an F is, probably some outdated system used by people who haven't caught on yet. It's definitely quite a lot, I'd expect somwhere from 600 to 1200degC. I know it's a fair bit more than 300degC, tried that (no not on a living sample) and no combustion.
I think it'll only combust if you can heat it quickly enough that it gets hot enough before charring sets in.

edit#2: In response to girth's comments (next guy down the list) that having a ray causing the fire rules out it as being spontaneous. I had my definitions for flashpoint backwards so I've got them fixed now. The ray is nothing but energy it is not fire. It causes a change in temperature this change in temperature causes a spontaneous burning. This happens at the autoignition temperature not at the flashpoint. light is not a source of ignition. it is not this beam of fire flying through the sky. and yes using a magnifying glass also counts. If you rule out heating using light you have to rule out heating all together and then what's left huh? Oh yeah... and combustion is a chemical reaction so you can't rule that out entirely either. The question boils down to whether or not humans have an autoignition temperature and the answer is yes.

Answer 3

It's not possible. People have been trying to prove it for hundreds of years and have failed. All instances where people have "caught on fire" have not been proven. Even though the cause of the fire might be unexplained, their is no proof that it is spontaneous combustion. Oftentimes, some kind of chemical reaction or other accelerator is found after a while.
Paul C is wrong by the way. The ray he put his hand under is what caused his skin to burn... it didn't "spontaneously combust" in the true sense of the word. True spontaneous combustion is when a person's body, under normal conditions, ignites itself. That's why I talked about chemical reactions and accelerators - they are what start the fires. By Paul C's definition, I could concentrate a magnifying glass on a piece of paper, and when it lights on fire, I could say it spontaneously combusted when all it did was catch on fire. Make sense? So no, human spontaneous combustion is not possible.

Answer 4

Theories about Spontaneous Human Combustion
- Alchoholism - many Spontaneous Human Combustion vicitms have been alcoholics. But experiments in the 19th century demonstrated that flesh impregnated with alcohol will not burn with the intense heat associated with Spontaneous Human Combustion.

- Deposits of flammable body fat - Many victims have been overweight - yet others have been skinny.

- Devine Intervention - Centuries ago people felt that the explosion was a sign from God of devine punishment.

- Build-up of static electricity - no known form of electrostatic discharge could cause a human to burst into flames.

- An explosive combination of chemicals can form in the digestive system - due to poor diet.

- Electrical fields that exist within the human body might be capable of 'short circuiting' somehow, that some sort of atomic chain reaction could generate tremendous internal heat.

No satisfactory explanation of Spontaneous Human Combustion has ever been given. It is still an unsolved mystery.

--- The link below also states what remains after SHC, types of SHC and much more. Quite interesting actually.

Answer 5

Spontaneous combustion would take place only if you could drive off enough water from the bodys surface to ignite it. This would require sustained temps over 500 F. These temps would be fatal.


Don't try it at home.

Answer 6

I think it's a myth. Nobody has ever been able to present a case of spontaneous human combustion that hasn't been shown to have had other causes.

Answer 7

As certain chemicals can when mixed in the right amounts suddenly burst into flames or at least cause extreme heat, then the Human body which is made of similar chemicals could if it had an over abundance of these certain chemicals.
So I presume the answer would be yes it is possible

Answer 8

The body must get warm..VERY HOT...form the inside out,,, this combustion,though with not leave any burn marks in its surroundings and with not catch anything else on fire,,,nor leaving ashes...if you would like a source,read Secrets and Mysteries of the World, by Sylvia Browne

Answer 9

You tie someone up and throw them into a bonfire. Voila, spontaneous human combustion!

Answer 10

Yes and no it all depends on how you look at it.
In this veiw i say yes. Friction and oxegen stat fires, not gasoline and a match (even tho it dose help) so if you could find away to creat so much fricion on yourself then yes u can catch fire.

But no b/c in reality if we did try to catch fire to ourself then one of many ting could appen 1. our hart could give up and stop, 2. our skin would peel of, or 3. you would feel weird doing so :)