Etymologically, the term wood preservatives defines that the wood preservation is the process of preserving wood from the wood destroying agents like insects or fungus so that the life span of the wood can be extended. It refers to the treatment of wood with chemicals to impart resistance to degradation and deterioration by living organisms. The proper application of chemical preservatives can protect wood from decay, and stain fungi, insects and marine borers, thus prolonging the service life of woods for many years.
The wood contents celluloses, hemicelluloses, starches and other susceptible materials that attract the fungi and insects to be degraded and eaten. After the preservative treatments, the fungi and insects cannot decompose and feed on these substances, hence the durability of wood is to be increased.
Wood preservative chemicals are toxic and hazardous. Preservative treatments provide long term resistance to organisms that cause deterioration. If it is applied correctly, it extends the productive life of timber by 5-10 times (Wikipedia, 2007). If left untreated, wood that is exposed to moisture or soil for sustained period of time will become weakened by various types of fungi, bacteria and insects.
In Nepal, the wood preservative treatment is the common practice for wooden transmission poles, and telephone poles. The treatments have been done for the poles of Eucalyptus camaldulensis. It has increased the value of Eucalyptus, and farmers have been getting good amount of money from the sale of Eucalyptus poles and this method has made possible to electrify the rural parts of Indial, since the treated poles last longer period and it cost less in transportation than other metal poles.
-- Well known for wood protection and restoration