• Use of a Treated Wood Product
  
  • Site Selection
    
  • Phaseout of CCA for Residential Uses
    
  • Allowable Uses of CCA-Treated Wood for Forest Service Projects
    
• Construction, Handling, and Field Treatment
  
• Disposing of Treated Wood
  

Use of a Treated Wood Product

Site selection, construction, and handling practices can help to minimize the risks of using wood products treated with preservative.

Site Selection

1. Stay as far away from surface water as possible, because contaminants move less freely in soil than water.
   
   
2. Place trail crossings of sensitive ecosystems at their narrowest points (minimizing the use of treated wood in sensitive areas).
   
   
3. Minimize the number of stream crossings (minimizing the use of treated wood over water).
   
   
4. Review the guidelines for particular environmentally sensitive species.

Phaseout of CCA for Residential Uses

The EPA worked with pesticide manufacturers to voluntarily phase out CCA use for wood products around the home and in children's play areas. Effective December 31, 2003, no wood treater or manufacturer may treat wood with CCA for residential uses (with certain exceptions).

CCA has been used to pressure treat lumber since the 1940s. Since the 1970s, the majority of the wood used in outdoor residential settings has been treated with CCA. Although pressure-treated wood containing CCA is no longer being produced for most residential uses, including decks and playground equipment, structures and facilities may continue to be used even if they were constructed with wood treated with CCA before the voluntary phaseout. An oil-based stain can help lock the CCA in place. See http://www.safe2play.org/assets/docs/factsheet.pdf.

Allowable Uses of CCA-Treated Wood for Forest Service Projects

The EPA's guidance for the use of CCA is the best source of information on allowable uses. See the Web site: http://www.epa.gov/oppad001/reregistration/cca/awpa_table.htm.

Decking, railing (figure 8), and rail posts must be built out of materials that are not treated with CCA. Forest Service applications where wood can be treated with CCA following the 2001 AWPA standards include:

• Highway bridges, (refer to C14, all members listed for highway bridge construction are allowed).
  
  
• Piles for bridges, boardwalks, and viewing platforms (refer to C3).
  
  
• Marine construction for saltwater use (refer to C18).
  
  
• Round posts and poles used in building construction (refer to C23).
  
  
• Sawn timber, 5 by 5 inches (about 13 by 13 centimeters) and larger, used to support residential and commercial structures (refer to C24).
  
  
• Structural glue-laminated members (refer to C28). (Treated dimensional lumber for both glue- and nail-laminated members may also be included under this standard.)
  
  
• Structural composite lumber (refer to C33).
  
  
• Kiosk shingles and shakes (refer to C34), and round posts and poles (refer to C23).
  
  
• Signposts (refer to C14), wood for highway construction.
  
  
• Horse stables, hay storage buildings, and equipment storage (refer to C16).
  
  
• Corrals/fences (refer to C16), wood used on farms, such as fence posts, round, half-round, and quarter-round fence rails. (Fence planks must be materials that were not treated with CCA.)

The list is partial; other uses may be allowed.

Figure 8—A bridge railing on the Trail of Blue Ice
in the Chugach National Forest, AK.

Excessive exposure to inorganic arsenic and wood treated with other preservatives may be hazardous to human health. Persons working with treated wood should take a number of precautions:

• Saw, sand, and machine the treated wood outdoors. Wear a dust mask, goggles, and gloves.
  
  
• Clean up all sawdust, scraps (figure 9), and other construction debris thoroughly and dispose of it in the trash (municipal solid waste). Do not compost or mulch sawdust or scraps of treated wood.
  
  
• Do not burn treated wood. Toxic chemicals may be in the smoke and ashes.
  
  
• After working with the wood, wash all exposed areas (especially the hands) thoroughly with soap and water before eating, drinking, using the toilet, or using tobacco products.
  
  
• Wash work clothes separately from other household clothing before wearing them again.

Figure 9—A tub can be used to collect sawdust when drilling
preservative-treated wood. Collecting debris during
construction helps to minimize environmental impacts.

These precautions will reduce your exposure from inhaling or ingesting sawdust, protect your eyes from flying particles, and prevent exposure to toxic smoke and ash. For more suggestions on avoiding unnecessary exposure to treated wood, the EPA has identified some common sense tips. Before working with treated wood, always consult the Wood Preservative Science Council's Inorganic Arsenical Pressure-Treated Wood consumer safety information sheet Web site (http://www.ccasafetyinfo.com), or call 800-282-0600 to listen to the information or have the consumer information sheet faxed to you.

During construction, any holes or cuts that penetrate untreated wood should be treated with preservative. AWPA Standard M4 provides guidance for field treatment. Typically, copper naphthenate is used. Be careful not to drip or spill preservative where it will contaminate the environment. Whenever possible, treat the exposed surface before assembling the structure at a sensitive area. Do not place field-treated wood into water or soil before all excess preservative has been wiped off or has soaked into the wood.

Be careful to collect sawdust and other wood waste and remove it from the worksite. Treated wood is not listed as a hazardous waste under Federal law. It can be disposed of in any waste management facility authorized under State and local law to manage such material.

Treated wood must not be burned in open fires or in stoves, fireplaces, or residential boilers, because the smoke and ashes may contain toxic chemicals. Treated wood waste from commercial and industrial sources (construction sites, for example) may be burned only in commercial or industrial incinerators or boilers in accordance with State and Federal regulations.

Generally, treated wood can be reused in a manner that is consistent with its original intended end use. The industry publication Management of Used Treated Wood Products (http://www.wwpinstitute.org/mainpages/disposaloftreated.shtml) addresses some of the legal questions regarding the disposal and reuse of treated wood. For more information, please contact the waste management agency in your State: http://www.epa.gov/epawaste/wyl/stateprograms.htm.