Manufacturers of pressure-treated wood who use chromated copper arsenate (CCA) are operating under another kind of pressure as wood treaters have agreed to make a transition away from the use of CCA in treated lumber by Dec. 31, 2003. The agreement is identical to the one between manufacturers in the United States and the Environmental Protection Agency (EPA).
Wood treaters will no longer use CCA to treat wood for non-industrial uses such as play structures, decks, picnic tables, landscaping, residential fencing, patios, walkways and boardwalks. Remaining stocks of wood treated prior to Dec. 31, 2003 can still be sold to stores and be used for residential construction in Canada. CCA will continue to be used for industrial applications , such as highway construction, utility poles and pilings.
Since the 1940s lumber producers and manufacturers have been injecting CCA into wood by a process that uses high pressure to saturate wood products with chemicals, creating what the public knows as “pressure-treated lumber.” CCA protects wood from dry rot, fungi, moulds, termites, and other pests that can threaten the integrity of wood products.
However, over the last few years the public perception that arsenic in CCA could be leaching out from wood treated with CCA is growing. The Pest Management Regulatory Agency (PMRA), which is part of Health Canada, has not concluded that CCA-treated wood poses any unreasonable risk to the public or the environment.
“If there was evidence of a threat to public health from CCA-treated wood, regulatory authorities in both Canada and the U.S. would have taken more drastic action, we would not be talking about a voluntary transition to alternatives over a number of years,” says Henry Walthert, the executive director of the Canadian Institute of Treated Wood in a recent media release.
The transition to non-CCA-treated wood has been facilitated by the PMRA’s completion of reviews of two alternative wood treatment products, ACQ (amine) and Copper Azole.
Mike Joseph, of Superior Thermowood in Thunder Bay, a one-year-old company, is betting that a wood-treatment process he has discovered will also be a substitution for CCA.
“We went to Europe and found a process that uniquely changes the cellular structure in the wood, making it lighter, more durable and more stable,” says Joseph.
“We are heading towards our goal of producing a product that will be very unique; it’s a natural product, we don’t add chemicals.”
He claims the process, which involves heating the wood, provides many benefits such as reducing the moisture content to zero, increasing bending strength by 15 to 20 per cent, increasing surface hardness and improving heat insulation by as much as 30 per cent.
Superior Thermowood is only in its preliminary stages of testing the process, but Joseph is confident his company can produce a value-added product that is both cost effective and environmentally friendly, and points out he has captured the interest of a few local investors.
The Canadian Institute of Treated Wood estimates that the value-added figure for treated wood in Canada is $750 million annually; the province of Ontario has the largest market share in Canada with 29 per cent.
The institute says the ecological contribution of pressure-treated wood is a recognised fact. Wood is the most environmentally beneficial building product. Preserving its service life in outdoor applications protects the environment from millions of tons of non-biodegradable alternatives such as plastic and concrete.