Wood impregnated with metal chelates dissolved in organic media tested for termite resistance

Wood manufactured products are subjected to biological decay due to fungi and insects. The use of copper chelates as biocides was proposed, due to their high stability which minimizes copper leaching in the environment. Considering the remarkable effectiveness showed by copper chelates on brown rot fungi, zinc and copper chelate complexes were prepared in order to have metal chelates soluble in organic media available. The present study aimed at evaluating these metal chelates complexes as preservative agents for wood treatment against termites. Trials were performed on Reticulitermes lucifugus (Rossi) and Kalotermes flavicollis (Fabricius). Results showed that in both termite species wood consumption was significantly lower on Cu-chelates treated samples compared to untreated wood, whereas the wood slices impregnated with Zn-chelates and the organic media alone gave an intermediate response. Interestingly, in one case solvent-impregnated wood was significantly more attractive than untreated wood for both species and further investigations are being carried out to clarify this behaviour.