Charcoal

I'd like to make some charcoal from some off-cuts of treated timber, 4x2 softwood, which I have left over as waste from a building project.
Does anyone know if the fact that it has been treated (don't know what with, presumably against rot and insect attack), will pose any problems once it has been reduced to charcoal.
What type of timber it is likely to be, it's just sold as sc4 softwood, I assume it's a pine type wood, i'd like the charcoal to have pine like properties.
Happy to have an experiment but don't want to waste my time if someone has already tried it and found it to be crap.
Thanks

I think it will most likely be CLS (Canadian lumber stock), thats what builders use as it's cheap and strong, did I mention cheap....
My mate makes charcoal from this as it is very consistant, don't think he uses treated wood though, I know he is very happy with the results.

Could you possibly describe the appearance of the lumber? That may provide some insight into what it is treated with. They used to treat wood with nasty things like arsenic in combination with copper and other things. I believe they've been moving toward treatments with things like boric acid and other copper salts. Copper is quite an effective agent to deter fungus and rot causing organisms. I doubt that the treatment agents would harm the char, or affect the final product too much. My main concern would be what else is coming off with the smoke.

im a carpenter by trade, and i can confirm, if is a green colour then its been "tanalized" and most properly contains arsenic compounds , i have a wood burner at home and they recommend you dont burn it, so i dont .although ive worked with treated timbers for structural roof members, no colour but strong odour, with the recommendation one, wears gloves/ washes their hands afterwards.
so id give it a miss myself

Thanks for the replies.
it's not cls, it's a rougher finish than that, and yes, it is a slightly greenish colour. When you look at a cut end you can see that the treatment has penetrated a couple of mm or so into the wood.
It's soft and splinters easily into long splinters where a drill penetrates to back side for example.
Daft thing is, if I don't charcoal it I will probably burn it, either way then it will go up in smoke.
Thanks again.
PS - I do also have cls off cuts and this appears to be untreated.

im a carpenter by trade, and i can confirm, if is a green colour then its been "tanalized" and most properly contains arsenic compounds , i have a wood burner at home and they recommend you dont burn it, so i dont .although ive worked with treated timbers for structural roof members, no colour but strong odour, with the recommendation one, wears gloves/ washes their hands afterwards.
so id give it a miss myself

Yeah I was in B&Q a while back and a guy wanted some "green treated" timber cuting but they wouldn't do it for him (health and safety)

Maxman