Pentachlorophenol (penta or PCP) was first introduced for use as a wood preservative in 1936 by Dow Chemical Company and Monsanto Chemical Com- pany.1 Penta has since been used as an herbicide on ornamental lawns, golf courses, aquatic areas, and rights-of-way; for control of subterranean termites; as an anti-microbial agent in cooling tow- ers, .
