While my wife Lynn and I aren't quite ready to build our cottage on Lake Wah-Wash-Kesh, we have spent considerable time discussing the type of cottage that we'd like. Generally, we want to build a small cottage that will fit in with the natural environment and which will disturb the forest as little as possible. We also will not use pressure-treated wood.

Lynn and I have always avoided using this wood and a recent article in The Ottawa Citizen supports our decision. The article was about pressure-treated wood, problems associated with this wood as well as the City of Ottawa's property-management branch's decision to stop buying this wood.

While I have never been comfortable with the idea of wood filled with toxic chemicals, I decided to do a little research into this product. Not wanting to bias the information I was about to acquire from the Internet, I typed a few general terms, like "wood preservative" and "pressure-treated wood"  into a search engine and then printed off more than 35 reports that appeared on my computer. These reports came from various sources including the wood preservative industry, environmental organizations, media as well as government agencies in Canada and the United States.

What is Pressure-Treated Wood?
There is more than one kind of pressure-treated wood, but the most prevalent kind, at least in North America, and the kind that is drawing considerable concern, is CCA (chromated copper arsenate) wood. The primary ingredients in this wood are copper, arsenic and chromium. CCA-treated wood has been in existence for more than six decades. The CCA chemical mixture is a pesticide which is effective in protecting wood from decay and damage from insects.

How is CCA-Treated Wood Made?
Simply put, CCA-treated wood is created when air and water are removed from the wood cells and replaced with a solution that contains chromium, copper and arsenic.

Problems With CCA-Treated Wood
CCA-treated wood causes a variety of problems for people, animals and the environment. CCA is a carcinogen. Arsenic is both poisonous and a carcinogen. Arsenic can be released from CCA-treated wood in various ways including when the wood is burned, when it is sawed or sanded, through direct contact and when acid (i.e. acid rain, acid deck washes etc.) comes in contact with the treated wood. Among other things, copper and chromium can poison plants and aquatic life.

Studies have shown that arsenic, chromium and copper leaches from CCA-treated wood. Soil beneath decks made from this toxic wood has elevated levels of arsenic, copper and chromium. According to an article on the Canadian Medical Association Journal's website, Health Canada, in the early 1990s, "...found arsenic around 10 play structures made from CCA-treated wood, with soil samples from one structure having an arsenic content 10 times higher than Canadian guidelines recommend." Children and pets should be prevented from accessing areas below decks, play structures and similar items that have been made with CCA-treated wood.

Tests have shown that cloths wiped over CCA-treated wood contain arsenic. Children, or anyone else, can easily ingest this highly toxic chemical after touching picnic tables, docks, play structures, tree houses or other structures made from CCA-treated wood and then putting their fingers in their mouths or eating food after touching this toxic wood.
 

Safety Precautions
CCA-treated wood needs to be handled with caution. Some safety measures to minimize problems associated with this wood include:

• Never burn treated wood.
• Thoroughly wash hands, and other exposed areas, after contact with treated wood – especially before eating and drinking.
• Don't allow food to come in contact with treated wood.
• Clean up and properly dispose of wood debris – including sawdust which should be collected in a drop cloth.
• Wear an appropriate mask, goggles and gloves when sawing, sanding or machining treated wood. Wear gloves when handling treated wood.
• Wash clothes (separately from other household clothes) after handling or working with treated wood.
• Don't grow edible plants near structures or objects made of treated wood.

Applying an appropriate coating to exposed surfaces of CCA-treated wood is also a good idea. Studies indicate that arsenic dislodged from CCA-treated wood surfaces can be significantly reduced if an effective coating is applied every year or two to the wood. Coatings, like oil-based stains, can also help to prevent the wood from cracking and splintering. Since some coatings are not appropriate for CCA-treated wood, it is a good idea to discuss a suitable coating with a knowledgeable paint or hardware store employee.

Alternatives
There are lots of alternatives to using CCA-treated wood. In many cases cedar, which is a naturally decay resistant wood, can be used. Other alternatives to CCA-treated wood include: concrete blocks, metal, plastic, stones, bricks and composite material. Another type of pressure-treated wood, ACQ wood, is less toxic than CCA-treated wood and does not contain arsenic.

Current Situation
In February the United States Environmental Protection Agency (EPA) announced that industry was phasing out the consumer use of CCA-treated wood. This wood will not be available for most non-industrial use in the United States by January 2004. At the beginning of April the Pest Management Regulatory Agency of Health Canada made a similar announcement. Many countries have banned this wood or restricted its use.

A Final Word
Millions of pounds of CCA are used each year to make CCA-treated wood. While this wood has a relatively long life, it does decompose releasing these chemicals into the environment. People use CCA-treated wood because it is relatively inexpensive and effective against insect damage and decay. Unfortunately, the toxic chemicals that make up this wood do not all remain in the wood. Arsenic is dislodged from the wood and the chemicals also leach from the wood. What price can be put on human health and the health of the environment?
 

Note: Shortly after finishing this column, newspaper articles reported unsafe arsenic levels in soil
in six Toronto parks. The soil was near playground structures that were built using pressure-
treated wood.