Frequently Asked Questions about Wood Preservation

More Information

Click for more information on the topics below: Topical Publication Lists   o Acid copper chromate (ACC)   o Alkaline copper quat (ACQ)   o Ammoniacal copper citrate (CC)   o Copper azole (CBA-A or CA-B)   o Copper dimethyldithiocarbamate (CDDC)   o Environmental impacts of treated wood and methods to reduce the impacts   o Disposal and reuse of treated wood   o Natural durability   o Control of moisture in buildings   o Experimental preservative treatments   o Research methodologies in the field of wood preservation   o Effect of preservative treatment on mechanical properties   o Wood products production and consumption   o Field treatment Links to other sources   o American Wood-Preservers' Association (http://www.awpa.com/)   o Forintek Canada Corp./ Canadian Wood Council (http://www.durable- wood.com   o Southern Pine Council (http://www.southern pine.com/)   o Western Wood Preservers Institute (http://www.wwp institute.org/)   o U.S. Environmental Protection Agency (http://www.epa.gov/)   o US Forest Service, Forest Products Laboratory (http://www.fpl.fs.fed.us/)     FPL Publications   Recent FPL Publications are generally availabe from our Web site at http://www.fpl.fs.fed.us/ publications.html as PDF files. The most recent FPL publications are listed in "Dividends from Wood Research," FPL's semiannual listing of new publications. Sections of the listing relevant to wood preservation are "Durability" and "Decay Processes and Bioprocessing."   o Most recent issue   o Cumulative list (January 1996 to present) Two chapters of the Wood Handbook are particularly relevant:   o Wood Preservation, Chapter 14   o Biodeterioration of Wood, Chapter 13 Send comments to: Carol Clausen, Project Leader Wood Preservation US Forest Service, Forest Products Laboratory One Gifford Pinchot Drive Madison, WI 53726-2398 cclausen@fs.fed.us top of page

Q: What research is FPL doing on wood preservatives?

The FPL wood preservation research program (RWU 4723) aims to investigate and develop recommendations on how to minimize leaching and environmental impacts of preservative-treated wood, facilitate the development of new preservatives by conducting studies on the treatability and durability of preservative treatments, including conventional treatments, the new generation of copper-based preservatives, and new experimental treatments, ensure the use of a diversity of wood species in treated wood applications, and
improve and accelerate test methodologies used to evaluate the long-term effectiveness and durability of potential new treated wood products.

For the past decade, much research on new treatment technologies at FPL and various universities has been conducted as part of the Timber Bridge Program (FPL Wood in Transportation). This program included research funded by the Federal Highway Administration. Additional information on timber bridges can be found at the website of the Forest Service National WIT Information Center. While the goal of the program was to expand options available in the construction of timber bridges, research on alternative preservative treatments has applications to the residential market affected by the restrictions on future use of CCA-treated wood. Included in the program were conventional preservatives, alternative copper-based preservatives (ACQ, CC, CDDC, and OC (oxine copper)), and several new experimental treatments. Research on new preservatives has also been conducted as part of other programs. A new research project with the Northeast Forest Alliance includes the preservatives CC, ACQ, and CA-B.

To ensure that preservative technology does not limit the utilization of our diversity of wood species, treatability and durability studies are conducted with a variety of wood species, including hardwoods and softwoods other than the traditional southern pine. Field plots are maintained in Wisconsin and at Harrison Experimental Forest in Mississippi. FPL has also been targeting the basic mechanisms of decay and identifying possible treatments that do not involve heavy metals. To address environmental concerns, we have investigated the leaching of wood preservatives and published guidelines on practices that reduce the introduction of preservative chemicals into the environment. Research aimed at the remediation and disposal of treated wood has also been conducted.

Frequently Asked Questions

The first questions address new restrictions on the use of CCA-treated wood and the available alternatives. Then other frequently asked questions on wood preservation and related topics are also addressed. With few exceptions, references in this document were limited to publications of the Forest Products Laboratory. These answers are not intended to represent a complete review of the available literature.

1. What are CCA, ACA, ACZA, etc.?
2. Is it true that EPA has banned CCA-treated wood?
3. What are the alternative types of treated wood for residential use?
4. Has FPL evaluated these treated wood products?
5. Should I have concerns about existing CCA-treated wood?
6. How do I dispose of treated wood?
7. What about naturally durable species?
8. How can I extend the life of untreated wood?
9. Where can I find the climate index map of relative decay hazard?
10. What research is FPL doing on wood preservatives?
11. What experimental preservative treatments for wood has FPL investigated?
12. What test methods are used to evaluate new preservative treatments?
13. What is the impact of preservative treatments on mechanical properties of wood?
14. How can I tell if my wood is properly treated?
15. Where can I find additional information related to wood decks?
16. What is the market for treated wood?
17. Where can I find lumber treated for both flame retardancy and preservation?
18. Does FPL have any information on remedial or field treatment of wood?