The Influence of Sample Origin on the Leachability of Wood Preservatives

Several studies have been conducted on impregnability of the raw material and large variations have been found. The leaching of wood preservatives into nature is a problem, especially agents that consist copper. Leachability of i. e. copper has been studied by several authors. This study tries to set the variation of leachability of Wolmanit CX-8 and Tanalith in system, evaluating the origin of a tree and the origin of a sample. Samples of Scots pine sapwood (Pinus Sylvestris) (20x20x50 mm) were treated with the wood protection agents Wolmanit CX-8 and Tanalith. The variation in leachability within trees, between trees and between different stands of Scots pine (in Norway and Denmark) was studied. The samples were climatized, impregnated with preservatives and leached according to standard EN84. The study indicates differences between the products. Stand location and samples position in a tree play a role in preservative leaching from wood, favouring southern located trees to be more prone to loosing preservative. Also the lowest part of the tree does not fixate preservatives as well as the upper parts.