ABSTRACT
Creosote and pentachlorophenol (PCP) are two of the major and highly effective organic wood preservatives. Creosote consists mostly of aromatic single to multiple ring compounds termed polycyclic aromatic hydrocarbons (PAH). Over 200 different chemical components have been identified in creosote; however, it is generally agreed that creosote contains several thousand different compounds which are identifiable with gas chromatography/mass spectroscopy (GC/MS). At least 16 PAHs found in creosote have been categorized as priority pollutants by the Environmental Protection Agency (EPA). Creosote is a blend of various coal tar distillates with specific physical characteristics that meet standards of the American Wood Preservers’ Association (AWPA). Creosote has been used worldwide for more than 150 years. During the early part of the twentieth century, there was a significant expansion and increase in the number of creosote treating plants for production of treated wood crossties for the expanding railroad industry in the USA. This demand for crosstie material peaked at about 70 million ties in 1920 and slowly declined to 50 million in 1925 and 30 million in 1930 (Webb, 1987). Since then the use of creosote has been declining. The annual USA consumption in 1993 was estimated at 73.7 million gallons (Micklewright, 1994).
