Polychlorinated Biphenyls (PCBs): Overview
Description
PCBs are mixtures of various isomers based on biphenyl. There are 209 individual possible PCB variants (also known as congeners). Approximately 100 of these congeners are present in various technical mixtures of PCBs that were produced commercially in large quantities until the late 1970s. Australia banned the importation of PCBs in 1975.
PCBs are amongst a broader group of harmful persistent organic pollutants (POPs) that are toxic, persist in the environment and animals, bioaccumulate through the food chain and pose a risk of causing adverse effects to human health and the environment. They are listed under the Stockholm Convention on Persistent Organic Pollutants for phasing out and eventual elimination. For more information see: www.environment.gov.au/settlements/chemicals/international/pop.html
PCBs have been used as coolants and lubricants in electrical equipment (such as transformers and capacitors), hydraulic fluids, additives in paint, carbonless copy paper, plasticisers and dye carriers. PCBs were used as they do not burn easily and are good insulators.
Substance details
Substance name: Polychlorinated biphenyls
CASR number: Many
Molecular formula: General Formula: C12H10-nCln (where n = 1-10)
Synonyms: PCBs, chlorinated biphenyls, Aroclor, Clophen, Fenclor, Kaneclor, Pyralene
Physical properties
PCBs range in appearance from colourless, oily liquids to more viscous and increasingly darker liquids, to yellow to black resins. The appearance depends on the chlorine content of the PCB. Some PCBs can exist as a vapour in air. They have no known smell or taste.
Chemical properties
PCBs are chemically stable, have good insulating properties and do not degrade appreciably over time or with exposure to high temperatures. They are very soluble in organic solvents.
Further information
The National Pollutant Inventory (NPI) holds data for all sources of Polychlorinated Biphenyls in Australia.
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