CPSC and EPA Release Reports on CCA-Treated Wood

May 11th, 2005

The U.S. Consumer Product Safety Commission (CPSC) and the Environmental Protection Agency (EPA) have posted on their websites interim results of a two-year study on the effectiveness of coatings (i.e., stains, sealants and paints) for reducing potential exposure to arsenic from chromated copper arsenate (CCA)-treated wood used in residential settings.

(See the Sealants and Alternatives to CCA-treated Lumber section of our Documents page for links to both reports.)

For homeowners and others who want to reduce their potential arsenic exposure from their decks or other CCA-treated wood structures, new studies show that use, at least once a year, of an oil-or water-based, penetrating sealant or stain can reduce arsenic migrating from the treated wood. The data show that oil- or water-based sealants or stains that can penetrate wood surfaces are preferable to products such as paint, because paints and other film-formers can chip or flake, requiring scraping or sanding for removal, which can increase exposure to arsenic. By selecting the proper coating for the initial application and re-coating, consumers can help minimize the potential arsenic exposure caused by scraping, sanding and power washing.

This information is based on first-year results from two-year studies initiated by CPSC staff and EPA in 2003, to determine if stains, sealants and paints are effective in reducing potential arsenic exposure from existing CCA-treated structures. EPA tested the performance of 12 coatings on older wood and CPSC tested eight coatings (seven were the same as those tested by EPA) on new (as of August 2003) CCA-treated wood. CCA was a chemical treatment commonly used in the past to prevent deck and playground wood from rotting.

Effective December 31, 2003, the use of CCA to treat virtually all residential uses of wood was eliminated. EPA and CPSC staff developed an externally peer-reviewed research protocol to study the performance and effectiveness of wood coatings. The joint study, which is slated to end in August 2005, continues to evaluate the performance of commercially available products, a combination of film-forming (e.g., paints) and non film-forming products (e.g., stains).

More information for consumers is available on EPA's website and on CPSC's website.