Since the 1970s, most of the pressure-treated wood used in the United States for outdoor structures such as playground equipment, picnic tables, benches and decks has been treated with the preservative, Chromated Copper Arsenate (CCA).

What is CCA?

Chromated Copper Arsenate was the primary preservative used in the pressure-treating process to protect wood against weather, mold and insects. Chromium was used to bind the two toxic metals (arsenic and copper) to the wood fibers, but it was later discovered that chromium was not as effective at locking in the arsenic and copper as originally thought. Studies show that CCA-treated wood is continually leaching (releasing) arsenic to the surface of the wood. Of the three chemicals (chromium, copper and arsenic), arsenic is considered the most toxic.

Where do you find CCA-treated wood?

CCA-treated wood has been used for outdoor residential structures such as playground equipment, fences, gazebos, decks and patios, landscaping timbers, foundations, walkways, boat docks, park benches, and picnic tables. It has also been used for outdoor industrial structures such as utility and construction poles, marine timbers and pilings.

Why the sudden concern about arsenic in CCA-treated wood?

Arsenic is known to cause cancer in humans and is much more toxic than previously believed. Arsenic is a potent skin, bladder and lung carcinogen. Arsenic is also linked to liver and kidney cancer, immune system suppression, increased risk of high blood pressure, cardiovascular disease, endocrine disruption (altering normal hormone levels or activity in the body) and diabetes.

How are children exposed to arsenic from playing on CCA-treated wood?

Recent studies have confirmed that high levels of arsenic can be released to children's hands by direct contact with arsenic-treated wood. Young children, in particular, are at risk of ingesting (swallowing) arsenic when they put their hands in their mouths after touching CCA-treated wood. Children are more vulnerable than adults for many reasons but particularly because their bodies are still growing and developing. Children may be at greater risk than adults because their livers metabolize the toxic metal more slowly.

Where can I find more information?

Please read the two-page factsheet, "What You Should Know About Arsenic-Treated Wood" and for more detailed information, go to "Frequently Asked Questions"

Safe Playgrounds is a project of the Center for Environmental Health (CEH) and was made possible by funds received by the Public Health Trust, a project of the Public Health Institute.