Products of Pyrolysis and Combustion of Liquid PCB Substitutes

Abstract

Although PCBs have been used as dielectric fluids since the 1930’s, concerns have been raised only relatively recently about the environmental persistance of these compounds, as well as possible adverse health effects attributed to exposure to trace fire byproducts. PCBs were first manufactured commercially in 1929, and were used as transformer and capacitor fluids, heat transfer fluids, plasticizers, and hydraulic lubricants. PCBs have desirable cooling, insulating, and dielectric properties, and hence were considered suitable fluids for use in electrical devices. Because PCBs are relatively nonflammable, they were thought to be ideal for use in transformers and capacitors in indoor locations. Despite these advantages, PCB use has, over the past 15 to 20 years, become restricted due to environmental and toxicological concerns. In 1971, the sole U.S. producer of PCBs began voluntarily reducing the production and distribution of PCBs in response to environmental concerns¹. In 1977, production of PCBs in the United States ceased entirely.