Confirmation of Safety and Long-term Durability of CCC (Chitosan-Copper Complex) as An Environmental Friendly Wood Preservatives

摘要本研究以化学安全试验及野外暴露试验为基础，验证壳聚糖铜配合物（CCC）处理木材的安全性及长期耐久性。本研究在食品及农用化学品安全与评价中心有限公司的私人检验部门进行了食用毒性试验（LD50）、眼部刺激试验、皮肤刺激试验、皮肤过敏试验及遗传毒性试验五项研究。CCC在眼刺激试验中表现出强烈的阳性反应。LD50试验的CCC值远远大于2000ppm。经验证，CCC具有很高的安全性，是公认的环保型木材防腐剂。通过现场试验评估了CCC处理木材（如CCC浸渍木桩和CCC处理的sugi原木工作台）的耐久性。在白蚁群附近埋藏7年的木桩未见损伤，在室外暴露4年的原木长凳也未见生物降解迹象。就抗白蚁和木材真菌侵害的生物变质机制而言，CCC在处理木材内的微分布似乎起着重要作用。铜元素选择性沉积在射线组织与轴向管胞之间、树脂管内和射线细胞之间形成的“细胞间空间网络”的自由空间内。铜元素的选择性沉积对褐腐真菌和白蚁的攻击非常有效。这些获得的结果在2002年在印度尼西亚举行的第五届国际太平洋地区木材解剖学家会议（PRWAC）和第四届国际木材科学研讨会（IWSS）上发表。

The purpose of this study is to confirm safety and long-term durability of a Chitosan-Copper Complex (CCC) treated woods based on the chemical safety tests and the field exposure testsThe safety of CCC was investigated at a private inspection sector of Safety and Evaluation of Foods and Agricultural Chemicals Center Ltd. for following five items, that is, poison test for eating (LD50), ocular irritation test, skin irritation test, skin allergy test and genetic-poison test. CCC showed strong positive reaction on ocular irritation test. CCC of LD50 test is much larger than 2000ppm. It was confirmed that CCC was very safety and able to recognized as an environmental friendly wood preservatives.Durability of the CCC treated woods, such as CCC impregnated wood-pegs and a CCC treated Sugi-log bench, was evaluated by the field tests. Wood pegs buried for 7 years near the termite colony showed no damages, and the log bench exposed for four years in outdoor also showed no signs of biodegradation.So far as the mechanism of anti-biodeterioration against termite and wood fungi attacks, the CCC microdistribution within the treated woods seemed to play an important role. The copper-elements of the CCC was selectively deposited within the free space of "intercellular spaces networks" which were formed between ray tissue and axial tracheids, within resin canal and between ray cells. This selective deposition of copper elements works very effectively against brown rot fugal attack and termite attack.These obtained results were presented at the fifth International Pacific Regional Wood Anatomist Conference (PRWAC) and the fourth International Wood Science Seminar (IWSS), both were held at Indonesia in 2002.