Orthodichlorobenzeiie has become industrially important in the past few years. In addition to its other uses it serves as an effective solvent in lacquers, varnishes and waxes. It is used extensively for the preservation of wood because of its destructive effect on termites. Orthochlorophenol is also used as a wood preserver.
Orthodichlorobenzene consists of benzene with two of its hydrogen atoms replaced by chlorine; the prefix "ortho" means that the two chlorine atoms are on adjacent carbon atoms. Orthochlorophenol consists of phenol in which the hydrogen atom on one of the carbon atoms has been replaced by chlorine.
The toxicity of these materials will bear observation. Little is known of the chlorobenzenes or chlorophenols, but of the chloronaphthalenes, which are related products, some are apparently nontoxic to the liver when inhaled while those that are toxic when inhaled are severe irritants of the skin. It is therefore considered of value