Chapter 1 - Wood-preserving chemicals

Abstract

This chapter describes the chemicals that are used in the preservation of wood and illustrates the pressure-treated wood manufacturing technologies. An understanding of both the toxic nature of chemicals used and manufacturing steps is critical to identifying and responsibly managing the many forms of pollution and waste generated in the production of treated wood products. Chemicals that are primarily used in preservation of wood are: coal-tar creosote, pentachlorophenol, inorganic arsenicals, and water-borne preservatives. Coal-tar creosote is a brownish black/yellowish dark green oily liquid with a characteristic sharp odor, obtained by the fractional distillation of crude coal tars. Pentachlorophenol is a synthetic fungicide that is part of the organochloride family. It has historically been used as a pesticide, herbicide, and wood preservative chemical. A major use of PCP is as a wood preservative for power line and telephone poles, cross-arms, and fence posts. Inorganic arsenicals are those wood-preserving chemicals that contain arsenic. Water-borne preservatives are used when cleanliness and paintability of the treated wood are required. Water-borne preservatives are included in specifications for items such as lumber, timber, posts, building foundations, poles, and piling.