Are there any special precautions that apply to treated wood that do not apply to untreated wood?
Treated wood should not be burned. If you burn the wood, you release the preservative constituents that are locked in the wood cellulose. Burning destroys the wood cellulose and the metals end up in the wood ash. If that ash is not properly handled, it could cause health or environmental concerns. Treated wood should not be used in direct contact with human food or drinking water. Do not use pressure treated wood for cutting boards for example.