CCA pressure treated wood: Concern or media hype?

There’s been a lot of attention in the media during the past couple of weeks concerning how toxic CCA pressure-treated wood is. Scientists a variety of sources are being interviewed, saying that tests performed over ten years ago attest to this wood’s toxic properties.

On the other hand, some literature on the Internet from sources such as the Canadian Institute of Treated Wood claim, “Numerous independent studies, including those commissioned by the U.S. Environmental Protection Agency (EPA) and the Consumer Products Safety Commission (CPSC) conclude CCA pressure treated wood poses no health threat to consumers.” [Henry Walthert, Executive Director Canadian Institute of Treated Wood,]

We consumers such as us are caught in the middle: who do we believe?

As usual, we all need to do our own homework. We need to look at the reports coming in from all sources and then make an educated personal decision. Tiresome? You bet. Necessary? You bet.

Here’s what I found out, to get the ball rolling.

1. What is pressure treated wood?

Environment Canada’s website at tells us “Pressure Treatment Performed at commercial treatment plants… uses high pressure to force the preservative into wood. It is one of the most effective wood treatment methods, and is used for long-term preservation where severe decay conditions exist.

2. What preservatives?

Quick answer: a variety depending upon how the wood will be used. The current concern focusses upon CCA or “chromated copper arsenate” which contains arsenic and copper. It is the arsenic, in particular, that scientists at the EPA, Health Canada and other organizations in Canada and the USA are particularly concerned about.

3. Why use CCA?

So that wood won’t rot: the copper acts as a fungicide, the arsenic acts as an insecticide. The concept sounds great… and environmentally sustainable… at first. After all, to preserve wood means fewer trees cut, less energy to continually replace the wood, less human energy expended to build structures like decks that can last for years if built with treated lumber.

4. What is CCA pressure treated wood?

A website located at tells us, “CCA pressure treated wood is the green-tinged lumber sold in almost every home center and lumberyard in America. It has the indisputable benefit of being highly resistant to rot and insects. The lumber is treated with a pressurized solution containing Copper, Chromates and Arsenic, hence the name CCA lumber.”

5. What’s the problem with CCA wood?

Origen Biomedical of Austin, Texas publishes a website. This organization claims to be a public information service. Their page asserts, “It is incredible, but a single 12 foot 2 x 6 contains about 27 grams of Arsenic — enough arsenic to kill 250 adults. Burning CCA wood releases the chemical bond holding Arsenic in the wood, and just one Tablespoon of ash from a CCA wood fire contains a lethal dose of Arsenic. [bold text is theirs] Worse yet, Arsenic gives no warning: it does not have a specific taste or odor to warn you of its presence. No one disputes that the ash from burning CCA wood is highly toxic: It is illegal to burn CCA wood in all 50 states. This has serious implications for firefighters, cleanup and landfill operations.

A Canadian web page found at (website of the Canadian magazine Natural Life Your Guide to Healthy Sustainable Living) sounds the alarm for kids in particular. “Children are more likely to be exposed to harmful levels of arsenic from play structures, picnic tables and decks than from drinking water according to a recent report called Poisoned Playgrounds from the Environmental Working Group (EWG), a California-based advocacy group.”

According to this website, most of the lumber that you and I purchase for our decks, picnic tables and other home projects is CCA pressure treated wood, which contains “22 percent pure arsenic.”

Barbara Sibbald, writer and editor of the Canadian Medical Association Journal, posted this to the eCMAJ website (

“Of even larger concern, was the arsenic on the wood surface. ‘It’s pretty clear there is a dislodgeable residue which with casual contact can be removed,’ says Connecticut Department of Health toxicologist Dr. Gary Ginsberg. Although virtually no arsenic is absorbed through the skin, it is readily absorbed orally, thus children, who frequently put their hands in their mouths, are considered most vulnerable.

“Thus, the ‘prudent public health message’ is to seal CCA-treated structures every 2 years with an oil-based stain, advises the state department.”

Accordingly, the state of Florida has shut down many playgrounds.

6. What does arsenic do to us?

“Arsenic is an acute poisoning hazard, can cause skin, bladder and lung cancer in humans and is linked to diabetes and endocrine disruption. Children are more susceptible than adults to the impacts of arsenic exposure.” ( ).

Yet another site (a Harvard University site at reveals lots about arsenic, its adverse (toxic) effects but also, simultaneously, its beneficial uses: “Arsenic has been used for many years for medicinal purposes. It used to be used as a cure for diseases such as syphilis and has been shown to assist in curing some leukemias. It was taken as a medicine in Fowler’s Solution for well over a century.”

7. Should we be concerned?

Frankly, I think so. Nova Scotia environmentalist Brian Bradley poses this ultimate question… then answers it for us at his website located at His article “Stealth Bombs: The Pressure Treated Wood Odyssey” discusses CCA pressure-treated wood in detail. Is he being alarmist? I don’t think so, particularly when it appears as if no-one, ultimately, seems responsible for the safety of this product.

Mr. Bradley writes, ‘Now you ask: “Just how serious can this situation be?” Serious enough that previously determined “safe” levels of arsenic are currently under the scrutiny of the Environmental Protection Agency (EPA) in the United States. Research that the EPA is reviewing points to the need to reduce the “safe” level from parts per million (ppm) to parts per billion. That’s a factor of 1,000 or, in other words it would take 1/1000th the amount of arsenic now to exceed a safe limit as compared to the amount that it did before.

It’s serious enough that you can obtain samples of the arsenic leaching from CCA wood simply by taking a clean cloth (or gauze pad dipped in distilled water, if you follow the more orthodox research note) and wiping it over the surface of all those sordid green coloured monoliths you find in the playgrounds, schools and public parks. After that single wipe, according to the tests completed by Canadian researchers, your cloth now contains arsenic. This in essence means, every time your kids touch these structures and then put their hands in their mouth, or eat some fruit, or finish their picnic lunches after touching CCA toxic wood, without first washing their hands, that they have now ingested arsenic.

8. What should consumers do?

Think before you buy. Do you need that product? What alternatives exist? Do your research and above all, give this issue some careful thought.

We consumers ought to be concerned about using CCA pressure-treated wood on our properties, in our schoolyards… anywhere, actually. From what I’ve read it does seem as if arsenic is released into the earth in which fenceposts or deck supports are dug. It contaminates the soil, living creatures within it, gets into the food chain, and also into the groundwater.

9. Alarmist?

This column is never intended to be alarmist. I write it because it is the “Environment Forum.” It is intended to be thought provoking. What do you think about CCA pressure treated wood?


Katharine Fletcher is a freelance writer whose deck is made from pressure treated lumber. Yes, she’s concerned. Contact her at