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Preliminary Results Of Wood Sealant Study Released
(Beyond Pesticides, May 12, 2005)
Preliminary findings from Environmental Protection Agency (EPA) and the U.S. Consumer Product Safety Commission (CPSC) studies conclude that penetrating oil- or water-based sealants or stain can reduce arsenic migrating from chromated copper arsenate (CCA)-treated wood, if used at least once a year. The data results from the first year of two 2-year studies have been peer reviewed. More information is available on the EPA and CSPC websites.

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. The EPA cautions that these are just preliminary findings and the final report should be available at the conclusion of the second year of study. The EPA suggests that consumers consider the required preparation steps (e.g., sanding, power washing, etc.) before selecting a product to minimize potential exposure to arsenic, both for initial application and re-coating.

EPA tested the performance of 12 coatings on older wood and the CPSC tested eight coatings (seven were the same as the EPA group) on new (as of August 2003) CCA-treated wood. CCA is a pesticide treatment commonly used past three decades to treat deck and playground wood that is susceptible to rot and insect damage. Wood treatment became necessary as the industry moved to fast growing pine trees from slower growing hardwoods that are more naturally resistant to insects and the elements. Scientific studies show that CCA treated wood can lead to acute symptoms such as irritation, vomiting, diarrhea. Studies also show that CCA can lead to cancer and neurological dysfunction. See Beyond Pesticides CCA factsheet for more information on the health risks associated with this chemical.

The widespread use of CCA treated wood, particularly in residential structures, leads to increased human exposure. Children are especially likely to be exposed due to common hand to mouth behavior. As of December 31, 2003, the use of CCA to treat virtually all wood intended for residential use was eliminated, however consumers should take preventive action on decks, playground equipment, picnic tables and benches, handrails, and other treated wood structures. CCA-treated wood is still used on utility poles, pilings, and in construction. For more information on the dangers and alternatives to wood preservatives, as well as measures to take to prevent possible harm see our wood preservatives page.

For more information on these studies, contact: EPA Media Contact: Enesta Jones, 202-564-4355 , and CPSC Media Contact: Scott Wolfson, 301-504-7908.

TAKE ACTION: Make sure that any existing CCA-treated wood around homes and in the community is removed or sealed. It is best to test soil around treated wood structures for dangerous levels of arsenic and chromium VI (a highly toxic ingredient byproduct of CCA). Urge your utility company to stop the use of CCA-treated utility poles, and replace those that people come into contact with in home yards, school yards, and in other places in the community where people, especially children, come into contact with the wood.