Efficacy of Fatty Acid Chemistry: Candidate Mold and Decay Fungicides

Although organic, lipophilic acids, such as acetic, propionic, sorbic and benzoic, have a long history as preservatives in the food industry, relatively high concentrations are required and their bioactivities generally pertain to retarding microbial growth rather than eliminating pathogens. Moreover, exclusive use of organic acids such as lactic or citric acid, alone, as broad-spectrum biocides, is generally not sufficient for long term control of mold fungi. However, specific organic acids (i.e., glycolic and L­ lactic), even at low concentrations, are now known to be potent synergists with certain fatty acids as broadspectrum, environmentally compatible fungicides. Specifically, low molecular weight, aliphatic fatty acids (mono-carboxyl compounds such as pentanoic to decanoic acids or C5 to C 10) at various application rates +/selected adjuvants have been examined as candidate mold and decay fungicides. Substantial evaluation of formulation homogeneity, stability of dilutions in water and fungicide activity of stable formulations, both for dip and pressure treated wood products, has been accomplished. Antimicrobial formulations having multiple mechanisms of action with greater formulation potency would be considerably more effective. The research effort is under a joint venture agreement between Summerdale, Inc. and Forest Products Laboratory (FPL), Madison, WI.