Here is a bit of interesting info:
"CCA treatment leaves about one ounce of inorganic arsenic in each 12 foot 2 x 6. This is
enough arsenic, if released, to kill about 250 adults." from:
http://www.origen.net/ccawood.html also from same source:
Burning CCA wood releases the chemical bond holding Arsenic in the wood, and just one Tablespoon of
ash from a CCA wood fire contains a lethal dose of Arsenic.
and
Even more astonishing, minute amounts of 'fly ash' from burning CCA pressure treated wood, can have serious health consequences. The Journal of the American Medical Association reported on a family that burned CCA in a
wood stove for winter heating. Their hair fell out, all family members suffered severe, recurring nosebleeds, extreme fatigue and debilitating headaches. The parents complained about 'blacking out' for periods of several hours, followed by long periods of extreme disorientation. Both children suffered frequent seizures described as 'grand mal'. The symptoms were finally traced to breathing minute amounts of arsenic laden dust leaking from the furnace as fly ash. The family's houseplants and fish died, too, victims of copper poisoning from the same dust. Peters HA, et al: Seasonal exposure to arsenic from burning CCA wood. JAMA 251:(18)2393-96, 1984)
So, please be careful handling that dust!