Since the 1940s, lumber producers and manufacturers have used a chemical compound mixture called chromated copper arsenate as a wood preservative. However, the E P A, the Centers for Disease Control, and the World Health Organization classify arsenic as a known human carcinogen. Manufacturing of arsenic in lumber was phased out in the end of 2003. However, many of us have this in our yards. Read here for healthier alternatives:
Along with Cedar and redwood, the following woods are considered resistant or very resistant to decay: bald cypress (old-growth), catalpa, black cherry, chestnut, Arizona cypress, junipers, black locust, mesquite, red mulberry, burr oak, chestnut oak, gambrel oak, Oregon white oak, post oak, white oak, osage orange, sassafras, black walnut, and Pacific yew. Naturally decay-resistant wood will reduce the need to apply toxic wood treatments that have known adverse health effects. FSC-certification ensures the wood has been harvested in a way that will minimize harm to forest ecosystems.
Limit the Use of Unsafe Treatments
A healthier alternative to chromated coper arsenate (CCA) wood treatment is alkaline copper quaternary (ACQ). ACQ is applied just like CCA, but it is made of 100 percent recycled copper as its main component and contains no harmful chromium or arsenic ingredients. Other less toxic chemical treatments include borates, ACA (ammoniacal copper arsenate), ACZA (ammoniacal copper zinc arsenate), ACC (acid copper chromate), and CZC (chromated zinc chloride).