Wolman E Natural Select: A Treated-Wood Alternative
Arsenic has taken a big hit recently—from studies showing elevated levels in school playgrounds in Florida to public outcry about President Bush’s decision to relax drinking water standards for the element. Not surprisingly, product manufacturers are getting the message. In the July/August issue of EBN () we reported on one playground equipment manufacturer abandoning CCA; in this issue we report on another: Kompan (see newsbrief at left). In a directly related move, one of the largest manufacturers of CCA has introduced to the U.S. market a nonarsenic, nonchromium replacement for CCA: Wolman® E.
Arch Wood Protection, Inc., a division of Arch Chemicals, Inc., which acquired Hickson International PLC in August 2000, now offers a copper-based preservative in its “Wolmanized®” line of chemicals for pressure-treating lumber. Wolman E has been available in Europe since 1992 under the trade name Tanalith E. It was referred to as “Copper Azole” in our March 1997 article addressing problems with disposal of CCA-treated wood (EBN ); at that time, Hickson had chosen not to market the chemical in the U.S. Wolman E is now licensed to seven pressure-treating plants in the U.S., with two to four others expected by the end of the year. Pressure-treated wood produced with Wolman E is being marketed under the name Natural Select™. Natural Select was first produced in the United States in the fall of 2000. Wood treaters that currently produce Natural Select treated wood are currently located in South Carolina, Louisiana. Pennsylvania, California, Oregon, and Washington.
Wolman E differs in a number of ways from ACQ Preserve™, the other widely marketed alternative to CCA. According to Huck DeVenzio, Marketing Manager for Arch Wood Protection, Inc., both ACQ and Wolman E are copper-based, but they rely on different co-biocides to supplement the primary fungicide: copper. “We think our preservative is superior because of its lower corrosivity and because our co-biocide has lower toxicity characteristics than the quaternary compounds used by our competitors,” said DeVenzio. Wolman E includes borates to improve decay resistance, though the company does not seem convinced that the borates really improve long-term performance. Pointing out that no one has yet found a way to lock borates into wood, DeVenzio said that “long-term testing has demonstrated that Natural Select wood does not rely on the borate for its effectiveness. Future versions of the product may not include the borate.”
Arch Chemicals is quick to point out that it remains fully committed to CCA and that the introduction of Wolman E in no way implies that there is anything wrong with the more common arsenic- and chromium-containing compounds. “We believe CCA serves and continues to serve many customers’ needs in terms of a long-lasting and easily available product,” said DeVenzio. The company says that alternative wood treatment technologies are emerging because of both regulatory restrictions and consumer concerns prompted by media reports. “Despite the lack of a scientific basis,” says DeVenzio, “these trends are happening; we recognize this and offer Natural Select wood as an alternative choice.”
Natural Select wood, treated with Wolman E, is priced by the distributor and retailer, factoring in costs of both the treatment chemicals and the wood (the price of which fluctuates widely). Natural Select wood does cost more than CCA-treated wood, however—typically 15–30% more, according to Arch Wood Protection. Mark Schwartz, whose company, Brooks Building Products in Greensboro and Cary, North Carolina, specializes in treated wood products for deck and dock builders, said the price premium for Natural Select over CCA is 25% for above-ground applications and 50% for in-ground applications (where higher retention rates are required).
Schwartz, who used to work for Koppers then Hickson (prior owners of the Wolman line), thinks Natural Select is a very good product that “addresses a developing need in the marketplace.” While he shares Arch Wood Protection’s skepticism of the level of risk posed by CCA, he says public perception is what counts. “This growing awareness and fear of arsenic will ultimately drive consumers toward alternatives,” he told EBN. To date, however, they have sold Natural Select for only about a dozen projects—just two of which used 100% Natural Select. He describes Natural Select as browner in color than CCA-treated wood and notes that some customers prefer the greenish color of CCA.
Schwartz’s company also sells the ChoiceDek™ recycled-plastic-and-wood composite decking (see EBN ), which he said is typically twice the price of CCA. With no splinters and a rougher surface texture, ChoiceDek is often used around pools and hot tubs, he says, even when treated wood is used elsewhere. He has also sold ACQ Preserve™ for several projects in which architects had specified arsenic-free wood (before the availability of Natural Select). Comparing Natural Select and ACQ-treated wood, Schwartz hasn’t experienced any field problems with ACQ, but he feels that the chemistry of Natural Select is better because it is noncorrosive.
Leathers & Associates of Ithaca, New York, has been designing school and community playgrounds throughout the U.S. for about 30 years, generally out of CCA-treated wood. Responding to concerns about CCA from the volunteer community groups they work with, the company now offers three options for playgrounds: CCA, ACQ Preserve, and Natural Select—their approach is to provide the playground committees with as much information as they can about these alternatives and let them make their own decisions. Leathers & Associates built their first playground using ACQ six or seven years ago, and their first out of Natural Select this year. According to company president Mark Leathers, concerns about CCA have significantly increased over the past six months. “It’s become an issue that isn’t going to go away,” he told EBN.
The company has used Natural Select wood in a couple projects so far, and several more are planned for this fall. On the first playground they designed using the product, “everyone came back raving about it,” he said. In this case, the community group had done all of the research into the new option, and Leathers followed their lead by specifying the product—the company always specifies dense structural-select (DSS) lumber, kiln-drying after treatment, then application of sealant on-site during construction. No problems were encountered with the Natural Select during construction. He has found that Natural Select lumber is about 20% more expensive than CCA-treated lumber and 5% more expensive than ACQ-treated lumber.
For more information:
Arch Wood Protection, Inc.
1955 Lake Park Drive, Suite 250
Smyrna, GA 30080
770/801-6600, 770/801-1990 (fax)
Brooks Building Products
P.O. Box 3244
Greensboro, NC 27402
Leathers & Associates
99 Eastlake Road
Ithaca, NY 14850