Ask A Scientist Chemistry Archive

name Susan V.
status educator
age 50s

Question - is charcoal made from treated wood byproducts now -- or
do we
really know or test the quality of the wood used to make sure it is
not polluted?

Also, doesn't burning charcoal indoors create dangerous CO2? 
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Susan V.,

Charcoal, wood is a highly porous form of amorphous carbon made from the destructive 
distillation of wood.  I would say that it is NOT made from treated wood byproducts 
because of the copper and arsenic in the treated lumber products.  I hope that this helps.

Unterman
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Worse, Much worse!  Burning charcoal indoors generates dangerous CO, carbon monoxide, 
in addition to CO2.
It's very easy to get someone killed doing that.

If there is too much CO2 in the room, you'll FEEL a panicky "cannot get enough air" 
feeling, and do something about it, saving yourself.
So CO2 is not a huge threat.
But CO does not make any such sensation until there is a serious dose already stuck in 
your blood.
Then maybe, only maybe, do you notice a headache or drowsiness, before it is too late.
It is even possible to leave the room feeling fine, then get quite stricken minutes later 
as the effects develop.
Blood which is damaged by CO takes weeks to be replaced, and the damaged blood is a 
continuing burden to your organs.

I think that the CO is almost always more threatening to an individual than pollution 
from treated wood.
And if the wood from which the charcoal was made  had been treated, say with Arsenic,
much of this may have left the wood in the high temperature charring process.
Anything organic that was in the wood is nearly irrelevant.
 It gets either evaporated or char-bound in the manufacturer's charring process, then 
 burned in your fire.
I guess aromatic organics such as benzene and naphthalene can escape from your barbecue.
If there was enough to matter, you could smell a solvent-like smell.
You already smell that with lighter fluid or some kinds of self-starting charcoal.

How you treat the charcoal, manage its fire, is what determines it is safety and 
environmental harmlessness.
Things like not breathing more of its fumes than needed, keeping it outdoors,
and keeping it hot enough and aired enough to burn to CO2 instead of CO.

Jim Swenson
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I am not aware of any regulations regarding the source of charcoal. The
major danger of burning charcoal indoors is carbon monoxide (CO) rather than
carbon dioxide (CO2). The former is very toxic, odorless and tasteless.

Vince Calder
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