Can treated lumber fence boards be used to make a raised bed container or will it leach chemicals?
Certified GKH Gardening Expert
This depends on what the lumber was treated with. The modern treatments are thought to be low risk, but to be safe, organic gardeners usually avoid any treated wood. You can also line the bed with a plastic liner intended for this purpose before adding soil.
The risky kind of treated wood was treated with arsenic compounds, which can leach into vegetable plants in small amounts. In the US, this treatment is no longer allowed in new treated wood, but salvaged wood may still contain it. Here is more information: