Performance of copper-based wood preservatives in soil bed exposures

Abstract

Copper-based biocides are widely used to protect wood from biological attack in a variety of environments. Chromated copper arsenate (CCA) is the dominant copper-based preservative for wood protection (J. T. MICKLEWRIGHT, 1989). First developed in India in the 1930s, CCA contains a very effective combination of materials. Copper provides protection against most organisms, chromium aids in the fixation of copper and arsenic to the wood, and arsenic provides supplemental protection against those organisms that are copper tolerant (W. H. HARTFORD, 1973). CCA provides excellent protection in most environments, but increasing perceptions of toxicity, leaching, and other potential environmental effects have stimulated the development of alternative systems that, while still containing copper, incorporate materials other than chromium or arsenic. A number of these systems use ammonia to solubilize copper. The fact that many of these alternative biocides perform variably with site suggests a vulnerability to copper-tolerant fungi (A. F. PRESTON et al., 1994: G. R. WILLIAMS et al., 1994). The implications of copper tolerance for the performance of these materials has been the subject of much speculation, but relatively little in the way of comparative data under high decay hazard conditions currently exists. To develop a better understanding of the effects of substituting alternative materials for chromium and arsenic in copper-based biocides, we performed the trials described in this paper.

Citation

Lebow, Stan T.; Nilsson, Thomas; Morrell, Jeffrey J. 1999/2000. Performance of copper-based wood preservatives in soil bed exposures. Material und organismen. Vol. 33, no. 3 (1999-2000): Pages 235-243