What exactly are they?
PCBs, as they are commonly abbreviated, are a group of synthetic chemical compounds which formally stand for polychlorinated biphenyls. They belong to a class of organic compounds called chlorinated hydrocarbons.
Above: the structural diagram of polychlorinated biphenyls These compounds can ONLY be prepared synthetically, when chlorine atoms attach to a biphenyl molecule (two benzene rings). Since up to ten chlorine atoms can be added to a biphenyl molecule in different configurations, there are as many as 209 possible compounds — 209 possible PCBs!
Their general molecular formula is C12H(10-n)Cln.
Also known as...
From a worldwide industrial standpoint, PCBs are more commonly identified by their trade names. Trade names include: Aroclor (United States), Asbestol, Plastivar, Pyralene (France), and Santotherm (Japan).
Above: Monsanto, a U.S.-based chemical
company, manufactured PCBs under the
trade name, Aroclor, from 1935 to 1977
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