Users Of Wood Preservatives Have Perplexing Questions To Ponder. Users of pressure-treated wood, one of the most popular outdoor building products of the last two decades, have some perplexing questions to ponder.
The dilemma is brought on by an agreement between the Environmental Protection Agency and manufacturers to phase out CCA-treated wood and move to other preservatives by the end of 2003.
CCA, or chromated copper arsenate, has been the main preservative for pressure-treated wood, which has been used by millions of homeowners and at many parks and playgrounds for decks, play equipment, picnic tables, boardwalks, fences, landscaping timbers, patios, outdoor furniture, and other outdoor structures. The preservative makes the wood highly resistant to rot, decay and insect damage.
The agreement, announced in February, will ban the use of arsenic in wood intended for most residential uses because, in the EPA’s words, “arsenic is a known human carcinogen” and “excessive exposure to inorganic arsenic can be hazardous to your health.” EPA hedges a bit in adding that, while it “has not concluded that there is unreasonable risk to the public… we do believe that any reduction in exposure to arsenic is desirable.”
The questions facing users of CCA-treated wood are: What do I do about all the CCA-treated projects already in use around the house, and should I continue to use CCA-treated wood in new projects until the end of next year.
Here are some answers:
Danger From CCA Treated Wood
Existing uses. Understandably, most users will not want to scrap their CCA-treated decks, picnic tables, and other structures, and they probably should not. There are some precautions that can be taken to reduce any danger from the arsenic in CCA.
But first, if a homeowner is in doubt about whether CCA-treated wood was used for a project, how can he or she find out?
Most CCA-treated wood is Southern yellow pine, a strong wood with a prominent grain pattern. CCA-treated wood generally started out with a greenish tint (from the preservative), but over time it turns gray like other woods exposed to outdoor conditions. The wood might have a stamped-on label indicating that CCA was used. In general, if a wood deck is not cedar or redwood, it is probably CCA-treated. If still in doubt, try to get information from the wood supplier or installer.
Regular sealing (annually or at least every two years) of CCA-treated wood can help protect users. The EPA recommends oil-based, semi-transparent stains for sealing. Paint or latex-based sealers are not recommended.
Never let food come into contact with treated wood, and always wash hands after contact with it. Never burn scraps of CCA-treated wood, even in an open fire. Instead, put scraps in the trash for burial in a landfill.
Future uses. Anyone planning outdoor projects will still be able to obtain CCA-treated wood through this year and next, and probably even longer, until existing stocks are gone. Each person will have to make his or her own decision, but I have already made mine: no more CCA-treated wood for me.
Excellent substitutes are available, although most of them cost more than CCA wood. Cedar is probably the most readily available alternative. It has natural resistance to rot and weather, and, in my experience, is less likely to warp and crack than pressure-treated wood. Redwood, teak and ipe are fine alternatives, but they are often expensive and difficult to find.
Pressure-treated wood using arsenic-free preservative appears to be the wave of the future. Already available at some lumberyards are treated woods such as Preserve and Preserve Plus, which use a preservative called alkaline copper quat, or ACQ.
For decking, boardwalks and some other uses, wood composites are an excellent choice. These are made of ground-up wood and plastic, and are sold at many home centers and lumberyards under various brand names.