Adam, He can safely use CCA for raised beds, the greatest risk being the construction phase, not growing food phase.
It is my understanding that it is never safe to touch PT wood. I have wiped PT wood of all ages with rags and with my bare fingers, and the arsenate consistently comes off. Hence the national attention brought to its use in playgrounds where children are constantly touching the structures in their play. Another issue I rarely hear brought up with this kind of thing is questioning the industry itself. What kind of waste is the PT wood industry putting into water ways and landfills and air? Do I want my dollars supporting that? I am ever-wary of descriptions of how to use toxic chemicals "safely." DDT is persistent in our soils from its use in the 1950s, and it was deemed "safe." Sadly, we are all compromised by chemicals and the "conveniences" they bring us. I imagine the list of toxic things that are a part of my daily life is pretty damn long, including this nifty computer I'm working on, and the fossil fuel truck that got me to work today. The caulk around my tub, the paint on my home, the rubber soles of my shoes, the nice finish on my hardwood floors... And given that, I do my best to be constantly vigilant about the choices I make and their consequences. Any one less toxic item I make use of, the better. It seems we have been choosing to be unaware of the consequences of our choices, on this planet, and in this world. It seems unawareness isn't working very well. "Don't go back to sleep." - Rumi
