Analysis of polychlorinated biphenyls in transformer oils

Polychlorinated Biphenyls (PCBs) were seen as a significant engineering advance when first commercially produced in 1929. They were used as insulators and cooling fluids in electrical transformers and capacitors. There are 209 PCB congenors that are chemically and thermally stable with low inflammability and reactivity. However,they are also highly toxic, suspected carcinogens and bioaccumulate in the food chain. Due to these characteristics they are listed by the United Nations as one of the sixteen worlds persistent organic pollutants POPs). By international agreement, undertaken by the UN, the production of PCBs has been banned and gradually their use will be phased out. Several tests and procedures are discussed in some detail in this research