Preservative-treated wood as a component in the recovered wood stream in Europe – A quantitative and qualitative review
R J Murphy, P Mc Quillan, J Jermer, R-D Peek
Wood preservatives have been used for the protection of timber products in the European market in appreciable quantities for about 100 years. Between the 1960s up to the present day this usage has been particularly noticeable. The aim of this paper is to present quantitative and qualitative data on the volumes of preservative treated wood placed on the market in the UK and Sweden and to evaluate the expected quantities of preservative treated wood coming out of service and into the ‘recovered’ wood stream in the future. Data are presented from a case-study in the UK on CCA (copper, chromium, arsenic) treated timber and projections on likely amounts of this entering the recovery stream up to 2061. It is estimated that in the UK in 2001 approximately 62,000m3 of CCA-treated wood required disposal and that this could rise to about 870,000m3 by 2061. The proportion of CCA-treated timber in all post consumer waste wood in the UK is predicted to rise from about 0.9% in 2001, to about 12.3% in 2061 representing a substantial component of the post-consumer wood stream. In Sweden statistics have been compiled for production of preservative treated wood for many years. The preservatives used for waterborne treatments have also changed significantly over the last 10 years from a dominant role for CCA to alternative, As-free systems. It is estimated that preservative treated wood will represent on average about 5% of the recovered wood flow in Sweden over the next 25-30 years and that this will represent an appearance of about 8000 tonnes of As, 7000 tonnes of Cu and 6500 tonnes of Cr.
These data and the possible disposal options for CCA and similar treated wood are considered in a life-cycle thinking context.