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Rockwood Press Release
Viance Study Reveals Evidence of Premature Decay
in Micronized Copper-Treated Wood
Findings to be Presented at IRG 39 Annual Conference
Charlotte, NC USA (May 13, 2008) – Findings from independently verified field tests conducted by Viance LLC suggest that micronized copper preservative (MCQ) does not provide adequate protection against premature decay in wood products, particularly in ground-contact applications. Implications for aboveground applications are still unknown. These findings are discussed in a paper entitled, “Field Stake Tests with Copper-based Preservatives,” which will be presented at the 39th Annual Conference of the International Research Group on Wood Preservation (IRG) in Istanbul, Turkey, May 25 – 29, 2008. The paper is being presented by Viance’s vice president of research and development, Dr. Alan Preston.
Dr. Preston authored the paper with a team of fellow Viance scientists, including Dr. Lehong Jin, Dr. Andrew Zahora, Paul Walcheski and Dr. Kevin Archer, as well as independent scientists Dr. Darrel Nicholas and Dr. Tor Schultz.
 Study Results
The on-going tests, set up in three geographically different, but complementary test locations are evaluating the performance of stakes cut from commercially treated wood. At all three locations, several of the stakes treated with MCQ showed evidence of premature decay after only nine months of exposure. All stakes treated with solubilized copper preservative (alkaline copper quaternary or ACQ), however, showed no signs of decay. An independent wood scientist, Dr. Darrel Nicholas, inspected the stakes at the decay test sites and verified the findings.
The test results suggest that MCQ is not sufficiently active as a fungicide in wood preservatives, and that it does not provide adequate protection against premature decay, particularly in ground-contact applications. Premature decay could lead to early product failure of treated wood products in service.
“We are aware of how alarming the implications of our findings could be to people in the wood treatment industry,” said Steve Ainscough, president and CEO of Viance LLC. “We are making all the results of the study available to the public through the paper being presented to the IRG, including our test methodology and analytical results. We believe that a transparent dialog about this matter is the best way to prevent early product failure and damage to the industry as a whole.”
What Prompted the Study
“When micronized copper wood preservatives (MCQ) were introduced to the market in 2006,” said Dr. Alan Preston, “some scientists questioned if micronized copper could penetrate wood cell walls to prevent soft rot for wood in service. In the absence of comprehensive, publicly available scientific information about the comparative performance of micronized copper wood preservative systems, our scientists initiated the study to get answers to these questions. The results so far surprised and concerned us, and as a responsible supplier we are sharing our findings with the industry.”
Study Methodology
The tests used stakes cut from four-by-four posts of southern yellow pine (SYP) purchased from two home centers in Charlotte, N.C. Material treated with MCQ was purchased from one retailer and material treated with ACQ was purchased from another. Copper penetration indicators used on cross-sectioned wafer samples from each post demonstrated complete penetration. Wafer samples were also analyzed for retention of the preservative components copper(Cu) and quat.
“Even though AWPA standardized testing requires that testers treat the materials themselves, we decided to obtain our materials commercially,” said Dr. Alan Preston, “As wood treatment formulations are proprietary, we could not replicate treatment in a commercial environment, and laboratory treatment would not yield real-world results. We wanted to assess the performance of treated wood that was available in the market, and decided that purchasing the wood from local retailers was appropriate.”
All end tag information was retained for traceability and photographic records were made of the materials throughout all stages of preparation. Stakes measuring 30mm by 30mm by 450mm were cut from the posts, avoiding heartwood and knots, once preservative retention levels were verified.
The stakes were distributed among three test locations: two in Hilo, Hawaii (one for decay testing, the other for termite testing), which is a well-known product research location in the wood treatment industry; and one in Tanegashima, Japan, for decay testing, which is used for product evaluation in the Japanese wood building industry. Untreated southern yellow pine stakes were used as controls at all three sites.
“The Hilo HI decay site has a rich silt loam soil type of volcanic origin. The termite site in Hilo can be characterized as sandy, free draining crushed gravel which is particularly conducive to allowing termite activity. In Tanegashima, Japan, the test site is characterized by an open canopy, sandy, light loam soil with an average annual rainfall of 80 inches,” said Preston. All three sites have been used in Viance research for a number of years and have been shown to be indicative of various locations throughout the US.
For a copy of Viance’s Treated Wood Alert brochure; the IRG paper, “Field Stake Tests with Copper-based Preservatives”; and the paper, “Evaluation of the comparative performance of Alkaline Copper Quat and Micronized Copper Quat formulations in field stake tests” by Darrel Nicholas, PhD, visit www.treatedwood.com.
About Viance LLC
Viance LLC provides an extensive range of advanced wood treatment technologies and services to the global wood treatment industry. With an expertise in wood biocides and wood protection chemicals, Viance provides high-level product support to its customers and innovative, advanced solutions that improve the performance and durability of wood and wood products. Viance is a joint venture between Rohm and Haas Co. and Chemical Specialties Inc., a wholly owned subsidiary of Rockwood Holdings Inc.
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