3.6 Wood..................................................................................................................................
3.6.1 Presentation
Wood is used in a very large range of applications: the paper industry, particleboard, the building sector,
furniture, packaging and bioenergy. All along the wood processing chain, wood wastes arise, resulting from its
cultivation in forests, sawing, processing to products and disposal, Significant amounts of the waste wood
generated in the UK arises from the construction and demolition sector.
The sustainable use of wood resources is also closely linked to the issue of forests preservation which is essential
for the protection of biodiversity and to tackle the climate change issue. Optimising the use of forest biomass by
valorising wood waste is thus recognised as a way to enhance long-term environmental sustainability.
Nevertheless, Daian & Ozarska reports (2009) that the wood recycling rate is low in comparison with other
wastes such as metals.
The available options for the end-of-life of wood waste depend on the waste characteristics since:
wood waste is a broad category that includes everything from wood dust from sawing or to
complete boards resulting from the demolition of buildings
wood waste can be raw or with additives such as glue or preservatives (CCA/CCB^3 or other metal-
containing preservatives for example).The main available options are recycling and incineration. The main uses of recovered wood are mulch, fuel,
recycled timber, animal bedding and recycling into particleboard. However, animal bedding and much are also
produced from forestry co-products. In Europe, the dominant routes are recycling into particleboard and energy
recovery (Daian & Ozarska, 2009). However, the contaminant content of treated wood is an issue for instance for
the production of composted products or animal bedding. There can also be a toxicity issue in the case of
incineration because of the fumes released during the combustion processes. Wood landfill is still in use in some
places but in European countries the recent EU waste directives have resulted in landfill disposal of wood waste
being either banned or made very expensive for companies or householders.
The management of wood wastes seems to receive little attention from LCAs practitioners since very few LCAs on
the subject have been published. The situation has therefore not evolved significantly since the previous edition
of this report which featured three such studies. However, a comparative study conducted by Petersen & Solberg
(2005) that analysed LCAs comparing the environmental impacts of substitution between wood and alternative
materials (concrete and steel) in the construction sector pointed out that wood has less impact than competing
materials on global warming, under the condition that the wood is not landfilled after use. This conclusion thus
highlights the importance of the handling of wood wastes.
Because of the lack of studies a comparative analysis between the various end-of-life alternatives for wood waste
could not be conducted but available literature has been analysed to enrich the debate.
(^3) CCA: Copper chrome arsenic, CCB: Copper chrome boric acid