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What Is CCA?
Chromated copper arsenate (CCA) is a water-soluble inorganic pesticide most commonly used as a wood preservative to make it resistant to attack by termites and fungi that cause decay. The wood is dipped in a solution of CCA and subjected to vacuum pressure to force penetration of CCA into the wood. CCA-treated wood is also referred to as pressure-treated wood and is known by the trade name Wolmanizedï®. Wood treated with CCA is used widely in outdoor structures such as decks, playground equipment, picnic tables, garden-bed borders and docks.
Pesticide Residue on the Pressure-Treated Wood Surface
Newly CCA-treated wood may have some pesticide residue left on the wood surface from the treatment process. Because CCA is water-soluble, rainwater can seep in and leach CCA onto the wood surface. Cracking of the wood as it ages speeds up the leaching process. The CCA residue can be wiped or dislodged from the wood surface and can stick to hands or clothing from contact with the wood surface.
Contamination in Soil From CCA-Treated Wood
Since CCA can be leached from CCA-treated wood by rainwater and weathering, the soil beneath and adjacent to CCA-treated wood structures has been shown to be contaminated by arsenic, chromium, and copper. When decks built with CCA-treated wood was coated with a waterproof sealant the soil underneath had lower concentrations of the metals.
Concern About Children's Exposure
Young children are more at risk of exposure to CCA because they tend to spend more time playing outdoors, and because they have frequent hand-to-mouth activities. When playing on playground equipment or decks built with CCA-treated wood, they can be exposed to CCA by touching the CCA leachate on the wood surface with their hands and then inadvertently ingesting the CCA on their hands by hand-to-mouth activity. The amount of CCA leached on the surface of the wood depends upon the type of wood and the age of the structure. The amount ingested is also dependent upon the frequency of hand-to-mouth activity.
Children may also be exposed to CCA in contaminated soil when playing under these structures by touching the contaminated soil with their hands and then placing them in their mouths.
Greatest Health Risk From CCA - Exposure to Arsenic
CCA leachate contains arsenic, chromium, and copper. Available information suggests that exposure to the arsenic in CCA-treated wood poses the greatest potential health risk. However, there is great uncertainty regarding the exposure dose that results from contact with CCA-treated wood.
How To Prevent Exposure to CCA
The following measures can prevent or reduce exposure to CCA:
- When working with CCA-treated wood, wear dust masks, gloves, and protective clothing to decrease exposure to sawdust (ATSDR 2007).
- Apply a sealant every one to two years to CCA-treated wood structures to reduce direct contact with the wood preservative (CDPH 2007; CPSC 2006).
- Do not allow children to play under CCA-treated wood decks, and encourage them to wash up after playing on decks or playground equipment.
- Use alternative building materials, such as plastics and hardwood, for outdoor structures (EPA 2008).
- Cover CCA-treated wood used for garden-bed borders with heavy plastic
Safe Handling and Disposal
- Retail stores that sell CCA-treated wood should have copies of the consumer information sheet that describes safe handling recommendations.
- CCA-treated wood may be disposed of as ordinary household trash, but do not burn CCA-treated wood because toxic chemicals would be released into the air or remain in the ashes (EPA 2008).
- Do not use CCA-treated wood as mulch or wood chips. Do not put sawdust from CCA-treated wood in the composting pile
ATSDR. 2007. Toxicological profile for arsenic (update). Atlanta: Agency for Toxic Substances and Disease Registry.
CDPH. 2007. Pesticides used in pressure-treated wood. Hartford: Connecticut Department of Public Health.
CPSC. 2006. Evaluation of the effectiveness of surface coatings in reducing dislodgeable arsenic from new wood pressure-treated with chromate copper arsenate (CCA). Draft Final Report. Consumer Product Safety Commission.
EPA. 2008. Chromated copper arsenicals (CCA).
Where can I get more information?
If you have questions or concerns, please contact your community or state health or environmental quality department or:
For more information, contact:
Agency for Toxic Substances and Disease Registry
Division of Toxicology and Human Health Sciences
1600 Clifton Road NE, Mailstop F-57
Atlanta, GA 30333
Phone: 1-800-CDC-INFO · 888-232-6348 (TTY)
Email: Contact CDC-INFO
ATSDR can also tell you the location of occupational and environmental health clinics. These clinics specialize in recognizing, evaluating, and treating illnesses resulting from exposure to hazardous substances.
Information line and technical assistance:
To order toxicological profiles, contact:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Phone: 800-553-6847 or 703-605-6000
Some PDF files may be electronic conversions from paper copy or other electronic ASCII text files. This conversion may have resulted in character translation or format errors. Users are referred to the original paper copy of the toxicological profile for the official text, figures, and tables. Original paper copies can be obtained via the directions on the toxicological profile home page, which also contains other important information about the profiles.
The information contained here was correct at the time of publication. Please check with the appropriate agency for any changes to the regulations or guidelines cited.
- Page last reviewed: March 3, 2011
- Page last updated: March 3, 2011
- Content source: Agency for Toxic Substances and Disease Registry