Making raised garden beds out of pressure-treated wood is not advisable.
Vegetables can absorb the metals into their root system, contaminating the entire plant.
Arsenic and chromium are carcinogens and mutagens, according to the Environmental Protection Agency, and humans can be exposed by eating contaminated plants grown near CCA-treated wood. Substituting recycled plastic lumber is a very good solution for raised garden beds. Recycled plastic lumber can also be used for decking, picnic tables, park benches, outdoor play structures, and porch floors. Wherever you are looking for products that won't rot from exposure to the weather, or will never need painting and won't splinter, plastic lumber is worth consideration. Recycled plastic lumber is now available in many sizes, shapes, and colors.