Chemical wood modification with dimethyloldihydroxy-ethyleneurea (DMDHEU) or its derivatives are applicable to both solid lumber and wood-based composites. Advantages of DMDHEU-based modification are an increase of dimensional stability and high durability against white, brown and soft rot fungi. At higher chemical loadings, the hardness of the wood is considerably increased. Due to the durability improvement against fungi, in combination with the hardness improvement, a certain resistance against termite damage could be possible. Two field trials were conducted against Coptotermes acinaciformis (Froggatt) in south-east Queensland, Australia and one field trial against Mastotermes darwiniensis Froggatt in northern Queensland with DMDHEU-treated wood. Both subterranean termites are of major economic importance in Australia. Four timber species (Scots pine, beech, slash pine and spotted gum) and two levels of DMDHEU were used. The results indicated that feeding pressure by the termites was sufficient within all trials for a valid test. DMDHEU successfully prevented damage by C. acinaciformis, but not by M. darwiniensis: Scots pine heartwood was resistant to both species. Scots pine sapwood appeared slightly more treatable with DMDHEU than beech. Implications for further research are discussed.

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