I have worked for a wood treating facility now for 10 years. We still are able to treat wood with CCA. ( copper Chromium and Arsenic ) We can treat wood for agricultural use with CCA. Wood being used for playgrounds, decks, picnic tables, and anything that may be coming in contact with humans with MCA. ( Micronized Copper Azole ) We have been selling wood treated with CCA lately to new hop farms that have been starting up here in the northern part of Michigan. The comercial hop farmers here know they are getting CCA and dont seem to be concerned about. My professional opinion, and from what I have done at my own home, I see no problem with using pressure treated lumber in a garden or agricultural setting. That is just my 2 cents. Take it for what its worth. If you have any question about treated lumber feel free to ask me. I will do my best to answer your questions.