CCA-Treated Wood
What Is CCA?
Chromated copper arsenate (CCA) is a water-soluble inorganic pesticide used as a wood preservative. It makes wood resistant to termites and fungi that cause decay. The wood is treated by dipping it in a CCA solution and then applying vacuum pressure to force the CCA into the wood. CCA-treated wood, also known as pressure-treated wood, is widely used in outdoor structures like decks, playground equipment, picnic tables, garden-bed borders, and docks.
Pesticide Residue on Pressure-Treated Wood Surface
Newly treated wood may have pesticide residue on its surface. Because CCA is water-soluble, rainwater can cause CCA to leach onto the wood surface, especially as the wood ages and cracks. This residue can transfer to hands or clothing through contact.
Soil Contamination from CCA-Treated Wood
CCA can leach from treated wood into the soil due to rainwater and weathering, contaminating the soil with arsenic, chromium, and copper. Using a waterproof sealant on CCA-treated wood can reduce the concentration of these metals in the soil underneath.
Concern About Children’s Exposure
Children are at higher risk of exposure to CCA because they often play outdoors and have frequent hand-to-mouth activities. They can be exposed to CCA by touching treated wood surfaces and then placing their hands in their mouths. The risk of exposure is higher in older structures where more CCA may have leached out.
Health Risks from CCA Exposure
The primary health concern from CCA exposure is arsenic, which poses significant health risks. However, the exact exposure dose from contact with CCA-treated wood is uncertain.
How to Prevent CCA Exposure
- Wear dust masks, gloves, and protective clothing when working with CCA-treated wood to reduce exposure to sawdust.
- Apply a sealant to CCA-treated wood structures every one to two years to minimize direct contact with the wood preservative.
- Do not allow children to play under CCA-treated wood decks and encourage them to wash their hands after playing on such structures.
- Consider using alternative materials like plastics and hardwood for outdoor structures.
- Cover garden-bed borders made of CCA-treated wood with heavy plastic.
Safe Handling and Disposal
- Retailers should provide consumer information sheets with safe handling recommendations for CCA-treated wood.
- Dispose of CCA-treated wood as ordinary household trash, but never burn it as it releases toxic chemicals.
- Do not use CCA-treated wood as mulch or wood chips, and do not add sawdust from it to compost piles.
References:
- Agency for Toxic Substances and Disease Registry (ATSDR). 2007. Toxicological profile for arsenic.
- Connecticut Department of Public Health (CDPH). 2007. Pesticides used in pressure-treated wood.
- Consumer Product Safety Commission (CPSC). 2006. Evaluation of surface coatings in reducing arsenic from CCA-treated wood.
- Environmental Protection Agency (EPA). 2008. Chromated copper arsenicals (CCA).