I coat the stands and the outside of the hive/super body with copper naphthelate (NEVER the inside) before I paint them because the heat, humidity, and the amount of rain we get would reduce them to rot in a pretty short period of time. I've accidentally left an empty cedar super outside and it didn't take any time at all to develop a mold/mildew issue... it definitely looked like something I wouldn't want to eat off of either!
I ended up power sanding it (as clean as I could) before I put it back on the hives.
I personally would not use WOOD itself that is treated, as I don't feel the bees should come in contact with any treated area. If you're considering building items with treated wood, take a careful look at what it is treated with... (you can usually ask for an MSDS from the store/supplier.) If you're cutting, sanding, etc. with it then you're going to breathe and absorb it as well!