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What Lumber Is Affected? |
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From Stan Lebow, USDA Forest Service, Forest Products Laboratory, Madison WI Art and others: The effect of the CCA label changes as it relates to FS construction is a little complicated. Although the intent of the label changes was to limit residential use of CCA, the way they went about the changes has broader implications. Basically, they went through the 2001 edition of the American Wood Preservers Association Book of Standards and picked out certain commodity standards that would still be allowed. Most notably, material produced under AWPA Standard C2 (Lumber, Timber, Bridge Ties and Mine Ties) will NOT be allowed. This affects most dimension lumber, even if it's being used in a nonresidential application such as decking in a FS boardwalk. On the other hand, material produced under AWPA Standard C14 (Highway Construction) can still be treated with CCA, including dimension lumber. Also, material produced under AWPA Standards C3 (Piles), C4 (Poles), C23 (Round poles and posts), C24 (Sawn timbers over 5in. thick) and C28 (glue-lam, etc.) can still be treated with CCA. Note that this label change does not affect any treated wood produced before 2003. So, if you've got CCA treated wood in storage somewhere you can use it the same way as before. EPA's concerns with CCA are focused on cancer risk from children's hand-to-mouth exposure from playing on treated play structures. Even in that case the risk is borderline enough that EPA is not currently recommending removal of existing play structures. Second highest concern appears to be children's hand-mouth exposure from kids crawling on decking. In both cases the assumption is made that the child has repeated long-term exposure such as at a residence or day care center. Because little children do not typically encounter prolonged exposure to most FS applications of CCA treated wood, most FS use would not even be on the radar screen of concern. Still, FS new construction of items such as playground equipment or picnic tables with existing stocks of CCA treated wood is likely to draw concern/criticism. The CCA alternatives all contain (and appear to leach) more copper into the environment than CCA. Because of this, CCA may have an advantage in applications such as bridges. For more information on environmental effects of treated wood see publications at: Environmental Impact of Preservative-Treated Wood in a Wetland Boardwalk (PDF 2.6 MB) http://www.fpl.fs.fed.us/documnts/fplrp/fplrp582.pdf Guide for Minimizing the Effect of Preservative-Treated Wood on Sensitive Environments (PDF 1.8 MB) http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr122.pdf Assessment of the Environmental Effects Associated With Wooden Bridges Preserved With Creosote, Pentachlorophenol, or Chromated Copper Arsenate (PDF 1.5 MB) http://www.fpl.fs.fed.us/documnts/fplrp/fplrp587.pdf ++++++++++++++++++++++++++++++++++++++++++++ Phone: 608-231-9411 |