Wood treaters in the U.S. have voluntarily agreed to phase out the use of copper chromated arsenate (CCA) for the use of treated lumber products, and it's expected that a similar agreement will soon be reached in Canada.
In the U.S., after December 31, 2003, wood treaters will no longer be able to use CCA to treat wood for use in decks, play structures, landscaping timbers, residential patios and other uses. It will still be allowed for some applications, such as structures to be used in salt water and for highway construction purposes. Structures already built with CCA products are not affected, and CCA-treated products will continue to be sold until the end of 2003.
In Canada, the Pest Management Regulatory Agency (PMRA), part of Health Canada, is also discussing a phase-out of CCA with manufacturers. "The PMRA is currently in the process of communicating with CCA manufacturers in order to facilitate a similar voluntary transition to non-arsenic containing wood preservatives in Canada," says a PMRA document, adding that there are alternative products to CCA currently registered for use in Canada, such as alkaline copper quaternary, which are similar to those registered by the Environmental Protection Agency (EPA) (www.epa.gov) in the U.S. for use in wood treatment.
If health and environmental concerns don't prompt the Canadian industry to follow the American's lead, economics will. The industry exports more than $20 million worth of treated wood to the U.S. each year not a huge number, but enough to seriously hurt Canadian manufacturers currently exporting. The EPA says it believes "that any reduction in the levels of potential exposure to arsenic is desirable," but that it has "not concluded that CCA-treated wood poses any unreasonable risk to the public or the environment."
Henry Walthert, executive director of the Canadian Institute of Treated Wood (www.citw.org), says, "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."
CCA is the most widely used preservative in the wood treatment market, and has been manufactured for about 70 years. But some environmentalists have claimed for years that the chemicals used in the treatment produce a health risk, particularly for children. A Health Canada fact sheet says, "It is possible that some of the preservative will be dislodged, depending on various factors such as wood species, treatment practices, age in service and the environment in which the treated wood is installed. It is known that treated wood continually exposed to water in damp soil will lose more preservative than that exposed to an occasional rainfall. These factors are currently being re-assessed as part of the re-evaluation of CCA."
The American Wood Preservers Institute (AWPI) however, says "the fundamental safety of CCA-treated wood has not changed, but perceptions in the marketplace have." It says, "Study after study has shown (CCA treated wood) is safe. One analysis by the Florida Department of Health shows that a child would have to eat a spoonful of dirt taken from right next to a CCA treated play set every day, for 30 years, before there would be a potential health effect."
Three U.S. manufacturers have already developed new wood preservatives, but they are not yet available in Canada and only limited supplies of wood treated with the new preservatives are available in the U.S. The AWPI says the new generation of wood preserved products may cost 10 to 20 per cent more than the CCA treated wood.
The EPA points out that there are several other alternatives to treated wood, such as untreated wood (cedar and redwood) and non-wood alternatives such as plastics, metal and composite materials for decks and fences.