The safety of pressure treated lumber in the garden has been the subject of much debate in recent years. Soon the decision of whether or not to use this lumber to build raised beds or compost bins will be out of your hands. Over the next two to three years, pressure treated lumber containing chromated copper arsenate (CCA) will be phased out. CCA ? a pesticide that contains the known carcinogen arsenic ? is applied to 90 percent of this lumber as a preservative. CCA wood is currently used extensively in outdoor projects including decks, playground structures, and fences, as well as retaining walls and raised beds in the garden. The gradual phase out of CCA-treated lumber will allow time for the industry to switch to alternate preservative treatments. The EPA is not advising people to remove existing structures made of treated wood since the levels of arsenic that leach from the wood decline dramatically over time. However, painting or periodic sealing of treated lumber may be advisable as a way to reduce any risks from arsenic. More information will be forthcoming as the terms of the arrangement between EPA and the industry are finalized.