News Coverage
A Pimer On Treated Lumber Phase-Out
Arsenic-Contaminated Wood Will Soon Go Off the Market. What Happens Next?
Published December 20, 2003
Here are answers to questions about the phase-out of familiar treated lumber, and what the change will mean to homeowners:
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Why is lumber treated with CCA, or chromated copper arsenate, being targeted?
In the late 1990s, scientists around the world discovered that arsenic was more dangerous to humans than previously believed.
Lab tests over the years had shown that arsenic didn't pose a high risk of cancer to animals, said Dr. Rick Maas, director of the Environmental Quality Institute, a consumer product testing lab in Asheville. Based on those tests, scientists didn't think the amount of arsenic humans might pick up from treated lumber would be a serious threat.
Then, cancer started appearing in communities where arsenic occurred naturally in groundwater, Maas said. "In Bangladesh, where the (United Nations) had drilled wells. In Taiwan, in Arizona and New Mexico, cancer clusters started showing up."
That led scientists to look again at arsenic. "We discovered. that arsenic is about 200 times stronger as a human carcinogen than we had predicted, extrapolating from animal tests," Maas said.
That prompted a new look at CCA-treated lumber, a product in use for more than 60 years.
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What's the deadline and the latest news?
The treatment industry and the Environmental Protection Agency announced early last year that CCA would be voluntarily phased out after Dec. 31, 2003. Stores will be allowed to sell CCA lumber on hand early next year, but won't be able to stock more for residential use.
CCA still can be sold for marine and certain other uses, but Lowe's, Home Depot and other retailers who sell primarily to homeowners and residential contractors say they won't stock it.
In February and again in July, a U.S. district court in south Florida denied attempts to bring a class-action suit against makers and retailers of CCA-treated wood, including Home Depot.
Last month, the Consumer Product Safety Commission voted not to ban CCA-treated lumber for children's playsets, because most manufacturers no longer use the product.
Barry Klemons, owner of Archadeck in Charlotte, said the makers of playsets he carries quit using CCA-treated lumber about three years ago. New sets are made from lumber treated with different chemicals, or from cedar, redwood and other woods that are naturally decay-resistant.
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What chemicals will replace CCA?
There are several alternatives, but the most common will be ACQ, or alkaline copper quaternary. It's a copper-based formula, like CCA, but lacks the arsenic.
Charlotte-based Chemical Specialties Inc., one of the top three wood preservative suppliers in the world, has a plant and research facility in Harrisburg. Lumber treated with its ACQ product is marketed under the name ACQ Preserve.
Another ACQ-treated brand is Nature Wood by Osmose. Arch Wood Protection makes Wolmanized Natural Select, a copper azole-based treatment.
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How much will lumber treated with alternatives to CCA cost?
The industry estimates that alternatives like ACQ will cost 10 to 30 percent more, with a typical hike somewhere in the middle.
"We're hearing that about 20 percent would be an average increase," said Rick Hoke of Hoke Lumber in Davidson.
Most treatment companies have changed production to ACQ in anticipation of the deadline, said Dave Fowlie of CSI. ACQ, like CCA, is a water-borne preservative, Fowlie said, and companies can convert with minor plant changes.
Many observers say prices for ACQ-treated lumber will come down as production increases.
The NAHB Research Center, connected to the National Association of Home Builders, says availability of ACQ and other alternatives should greatly improve as CCA is phased out.
Kevin Powell of the Research Center staff also predicts that alternatives, such as wood-and-plastic composites, will become more popular and affordable. At this point, though, composites aren't suitable for the heavier framing timbers of decks. Those will still be treated lumber.
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Will the new generation of treated lumber look the same?
Pretty much. It's copper that gives treated lumber that familiar green tint. And the new woods will weather to gray like CCA.
You can use ACQ-treated lumber to repair or add on to an existing CCA deck. You can mix the two products, said Dave Fowlie of CSI. "It can be used in the same structure, and will perform very well."
You can use the same stains and sealers.
The industry's recommendations for handling and disposing of ACQ-treated lumber are the same as for CCA. Don't burn it. Don't eat, drink or smoke after handling it until you've washed your hands. Avoid sanding, or inhaling sawdust.
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Will I be able to use the same nails, screws and other hardware?
Maybe, if you've been using high-quality fasteners.
ACQ is more corrosive than CCA. Simpson Strong-Tie, the largest maker of deck fasteners in the world, says its research showed that some ACQ products are more than twice as corrosive as CCA. The treated lumber industry has long recommended the use of hot-dipped galvanized or stainless steel fasteners. That's more important than ever, Simpson says. And be sure to use galvanized products with the heaviest coating of zinc. "Simply put, more zinc means better performance," Simpson said in a technical bulletin.
Simpson recommends the use of stainless steel fasteners, anchors and connectors with treated wood when possible. If you're using galvanized products, use Simpson's ZMAX - which has 50 percent more zinc than the industry standard - or the equivalent.
The connectors and fasteners ALWAYS should be the same material. And NEVER use aluminum in contact with treated lumber.
You're likely to find several grades of galvanized products on the shelves of Lowe's, Home Depot and other stores for a while, said Richard Chapman, national ad director for Simpson. Products with less zinc will gradually disappear as ACQ replaces CCA.
Hot-dipped products can be identified by their rough surface, he said, the result of being dipped into molten zinc.
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Do I need to tear out my old CCA deck?
The industry and the Consumer Product Safety Commission say no; some environmentalists say yes.
"I'm not ripping my deck off," said Maas, whose lab in Asheville investigates CCA for those on both sides of the debate. "But I'm certainly going to keep it well stained."
Maas agrees with environmentalists that the threat from arsenic in treated lumber is real. Maas says - and the CPSC has stated - that the threat is primarily caused by hand-to-mouth contact after you've touched or handled treated lumber. That, of course, puts kids at special risk.
But we're all safer, Maas said, because we know about the threat. "If you contact this wood, you'll have arsenic on your hands. If all parents have that knowledge, this alone should reduce exposure substantially."
The EPA is studying the risk to kids. A draft of an early report is on Maas' desk. Maas and his colleagues say we need to learn more about how kids play on treated lumber structures, as well as about arsenic.
Meanwhile, though, make sure kids wash their hands after touching CCA-treated lumber on decks or playsets, Maas said. Make sure no food is placed directly on CCA-treated picnic tables.
And sealing your deck regularly with the appropriate products, as he suggested, will make it even safer.
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How often should it be treated, and with what sealers, stains and paints?
Early tests by industry and public health groups have shown that sealing treated wood can help reduce the threat. Last year, the N.C. Division of Public Health confirmed that weather-resistant polyurethane varnish and oil-based, semitransparent stains will "significantly reduce" the amount of arsenic exposure.
Maas said tests at the Environmental Quality Institute, which is connected to UNC Asheville, have revealed more about residual arsenic in the wood and the effects of sealers and stains.
One surprise was that the amount of arsenic falls quickly when treated wood is first exposed to the elements, and then it hardly falls at all as the years pass. "It drops to one third (of its original level), perhaps 35 percent, in the first three or four weeks," Maas said. "But then it appears that it never changes again. For the next 20-year service life, it doesn't drop."
The industry had been extrapolating a continued drop over the life of the deck, he said. Tests showed that clear, penetrating sealers reduce arsenic exposure for only four to six months, he said. After that, levels are the same as if the wood never had been sealed.
Semitransparent and solid stains "significantly" reduce arsenic for a year, or perhaps two, he said.Maas and UNC Asheville students are testing stains and sealers on a rooftop just outside his office. Large mirrors focus the sun's rays on the wood, speeding the weathering process. Sprinklers douse the samples regularly with water.
And students daily don rubber boots to tromp across the sealed and stained samples, to test how foot traffic on decks might wear through stain and cut its effectiveness.
Maas said the lab also is working with several companies to develop more effective deck stains and lumber-treating chemicals. He expects new sealing products to soon hit the market.
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Can I test my deck to determine how much arsenic is there?
Yes. Two groups offer CCA test kits, and the Asheville lab processes the results for both. You can order a kit from the Environmental Working Group, a nonprofit advocacy group based in Washington, D.C. The kit tests an area of about 100 square centimeters, or about the size of a child's hand, the group says.
There are three types of kits, priced at $15 and $30, plus $5 for shipping and lab supplies. For more information or to order, visit the organization's Web site at www.ewg.org.
Clean Water Lead Testing Inc., another environmental group, also offers an arsenic testing kit, Maas said. You can order online at www.leadtesting.org; price is $17. You can order the Clean Water kit by mail, too. Send a check for $17 to Clean Water Lead Testing, UNC Asheville, CPO No. 2331, Asheville, NC 28804.
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Where can I learn more?
Many industry and environmental groups, as well as research and government organizations, share information on their Web sites:
Environmental Quality Institute: www.unca.edu/eqi.
Consumer Product Safety Commission: www.cpsc.gov.
Environmental Protection Agency: www.epa.gov.
Environmental Working Group: www.ewg.org.
Clean Water Lead Testing: www.leadtesting.org.
National Association of Home Builders Research Center: www.nahbrc.org.
American Wood Preservers Institute: www.preservedwood.com.
Arch Wood Protection: www.wolmanizedwood.com or www.naturalselect.com.
Chemical Specialties Inc.: www.chemspec.com or www.treatedwood.com.
Cox Industries: www.coxwood.com.
Simpson Strong-Tie: www.strongtie.com.