What is one toixc chemical produced by burning wood?
Creosote, benzo (a) pyrene, dioxins, furans, carbon monoxide,
sulphur dioxide and a whole host of others, but that should be
enough to be going on with.
All wood, whether it's construction timber or straight from the
pristine forest, contains sulphur and chlorine in differing amounts
which produce some fairly unpleasant compounds when burnt.
It's all relative though, as so do cars, buses, trucks, planes
and cigarettes (in much, much larger amounts).