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Polychlorinated biphenyls (PCBs) are organochlorine compounds with the formula C 12 H 10−x Cl x; they were once widely used in the manufacture of carbonless copy paper, as heat transfer fluids, and as dielectric and coolant fluids for electrical equipment. [2]
Congener descriptors give a shorthand notation for geometry and substituent positions. The twelve congeners that display all four of the descriptors are referred to as being "dioxin-like", referring both to their toxicity and structural features which make them similar to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2378-TCDD). [1]
2,2',3,3',4,4'-Hexachlorobiphenyl is an organic chemical and belongs to a group of compounds called polychlorinated biphenyls. This group of organic compounds was used in transformers as dielectric fluids, until production was banned in 1979.
Biphenyl (also known as diphenyl, phenylbenzene, 1,1′-biphenyl, lemonene [4] or BP) is an organic compound that forms colorless crystals. Particularly in older literature, compounds containing the functional group consisting of biphenyl less one hydrogen (the site at which it is attached) may use the prefixes xenyl or diphenylyl.
There are 209 PCB compounds. Analogously to PCDDs at least two lateral chlorines in each ring in positions 3,4, and/or 5 are needed for dioxin-like activity. Because the AH receptor requires a planar (flat) structure, only PCB congeners that can rotate freely along the C—C axis between the rings can attach the receptor.
A group of carcinogenic organic compounds, polychlorinated biphenyls (PCBs), is an example of a congener grouping. The number and locations of Cl groups can vary. In chemistry, congeners are chemical substances "related to each other by origin, structure, or function". [1]
General structure of a PCB. Polychlorinated biphenyls (PCBs) are various biphenyl based artificial products that are widely used as a dielectric fluid, industrial coolant, and lubricants in the 1960s and 1970s. There is no evidence its synthesis occurs naturally. They are classified as persistent organic pollutants.
Polychlorinated biphenyls (PCBs) were once commonly used electrical insulators and heat transfer agents. Their use has generally been phased out due to health concerns. Their use has generally been phased out due to health concerns.