???Organic Acid Formulations for Wood Protection: Inhibition of Mold and Decay Fungi???

Summerdale, Inc. and Forest Products Laboratory (FPL) will focus on above-ground applications of waterborne preservatives for indoor and outdoor residential lumber. Specifically, fatty acid-based formulations +/- adjuvants will be targeted for use on a) indoor lumber and wood composites and b) exterior residential (above ground) such as decking. However, further Phase II development of outdoor residential markets will depend on Phase II results from replicated leach trials. Fatty acid/adjuvant control of mold/decay fungi and termites must be sufficient; i.e., where preservative is retained and pesticide performance is acceptable after standard leach trials. Also, multi-year field trials, testing both stake and above-ground durability of treated specimens, are planned. The trials provide a very rigorous examination of preservative long-term efficacy. In-ground stake testing of several formulations has already been initiated. It is conceivable that formulations may not show long-term protection during prolonged, in-ground contact. Nevertheless, durability of treated-wood for exterior residential (above-ground) can be determined from the accelerated stake and above-ground test results. Over 82% of all waterborne preservatives were used on lumber and timber. An estimated 183.2 million pounds of waterborne preservatives were applied in 2004 and that the largest market for treated wood was residential. The largest growth was for copper-rich ACQ (and CA) and inorganic boron preservatives. ACQ, alone, had 46.7% of the waterborne preservatives market in 2004. Over the last several years, MCQ (micronized copper quats) has penetrated this market. Currently, copper-based preservatives are used to pressure treat lumber for numerous residential applications such as decking, outdoor furniture, fences, play structures, etc. Novel fatty acid-based preservatives, as exterior treatments, can be: a) potential "stand-alone" replacements for selected copper-based products (i.e., ACQ) used above-ground and b) as combination treatments with selected, existing products. An effective stand-alone product and/or a combination treatment should be of interest to a licensee. An acceptable, stand-alone formulation, relative to an existing wood preservative, should have improved or superior deterioration control and comparable or improved cost and other features (better human and environmental safety, less metal corrosivity, acceptable appearance of treated wood, etc.). Since dip and pressure treatments are used by wood preservers (typically at factories or lumber mills), both application methods for exterior applications will be examined. However, formulation development will be targeted toward both interior and exterior treatments and include control of mold and decay fungi and termites. Potential exterior treatments will also include a determination of formulation capabilities as an anti-sapstain.