1. Lai Huat Choi IUFRO All Division 5 Conference 5.03-IRG Regional Wood Protection Research Symposium

2. LAI Huat Choi* & Andrew WONG University Malaysia Sarawak (Unimas) Faculty of Resource Science and Technology 94300 Kota Samarahan, Sarawak,Malaysia. Influence of Heartwood Extractives on CCA Fixation and Leaching on Malaysian Hardwoods

3. Aim of work and method….  Study on the influence of methanol soluble extractives on CCA fixation and leachability of CCA treated permeable (Perah) and refractory (Acacia mangium) Malaysian hardwoods.  CCA fixation  Methanol-extracted heartwood wood blocks were subjected to different post-treatment storage (fixation) periods [0, 2 days, 1 wk, 2 wk,4 wk], using EN84 laboratory leaching test.

4. Results… Cu Cr As

5. Conclusions…   Methanol-extracted than un-extracted wood significantly (P<0.05) increased Cu penetration (treatability) of Acacia mangium heartwood, but no significant change for Perah heartwood   CCA components losses range: 6.85 – 45.5 µg/cm2 (Mean: 13.05 µg/cm2) Cu, 5.1 – 141.0 µg/cm2 (Mean: 31.14 µg/cm2) Cr and 4.43 – 48.1 µg/cm2 (Mean: 13.10 µg/cm2) As.   Significantly higher (P<0.05) Cu, Cr and As leaching rates in unfixed treated than fixed treated heartwoods with and without extraction   Significantly higher Cu, Cr and As leaching rates in extracted than un-extracted unfixed treated heartwoods   Significantly reduced CCA Cr and As leaching rates for extracted than un-extracted fixed treated heartwoods of both Malaysian species   Extracted fixed treated heartwoods showed higher Cu leaching than un-extracted counterparts.