Chromium, copper and arsenic can leach into soil or water when wood treated with chromated copper arsenate (CCA) is exposed to the environment. Many factors can affect the amount of leaching that occurs from treated wood. Such factors include how long the wood has been exposed to the environment, the size and type of wood that was treated, whether the wood is coated with a sealant, water movement, and the type of soil. The chemicals that leach from CCA-treated wood can accumulate in soils near the wood, but under certain conditions, the chemicals can travel farther. In general, CCA chemicals are least mobile in organic soils, slightly more mobile in clay soils, and most mobile in sandy soils or water.
If you have questions about CCA, or any pesticide-related topic, please call NPIC at 1-800-858-7378 (8:00am - 12:00pm PST), or email us at firstname.lastname@example.org.