Traditionally treated wood is not considered organic, because it releases harmful chemicals over time.
The Final Rule of the National Organic Program (NOP) prohibits the use of lumber treated in traditional means for organic applications such as fence building on an organic farm, says agriculture specialist Lance E. Gegner of the National Center for Appropriate Technology. Gegner reports that there are many organic wood treatments available to producers as well as some options for home wood treating. The NOP has not yet approved all of these products. Most "organic" wood treatments will need special approval by the NOP before it allows their use in organic farm settings.
Borates
Gegner cites borates--boric acid and borax--as old standbys for alternative wood treatments. The weakness of borates is their water-soluble nature. When in contact with soil, borates leach into the water in the soil and leave the wood unprotected. Because of this, borate-treated wood is not allowed in organic uses unless it is at least six inches above the ground.
Ammoniacal Copper Citrate
Gegner states that ammoniacal copper citrates are a new wood treatment made of a copper and citric acid mixture dissolved in an ammonia and water solution. The NOP has not yet approved this relatively new technology for organic uses.
Copper Azole
Gegner next lists copper azole, a mixture of copper, boron and azole dissolved in an ethanolamine and water solution, as an organic wood treatment. Like ammoniacal copper citrate wood treatments, the NOP has not yet approved copper azole treatments.
Alkaline Copper Quaternary
The final production wood treatment Gegner discusses is alkaline copper quaternary treatments. These wood treatments contain copper and quaternary ammonium and are unsuitable for gardening purposes due to the ability copper has to leach from these wood treatments into the soil. The NPO has also not approved alkaline copper quaternary wood treatments for organic uses.
Home Treatments
Gegner also lists home wood treatment products Wood Impregnation No. 99 from Bioshield Paint Co. of Sante Fe, New Mexico, AURO No. 121 Natural Resin Oil Primer from Sinan Co. of Davis, California, and Lifetime Wood Treatment from Valhalla Wood Preservatives Ltd. of Calgary, Alberta, Canada. The NPO has not approved any of these products.
Tags: wood treatments, copper quaternary, organic uses, organic wood, wood treatment, alkaline copper, alkaline copper quaternary
