Polychlorinated biphenyls transformers

Seto M, E Masai, M Ida, T Hatta, K Kimbara, M Eukuda, K Yano (1995) Multiple polychlorinated biphenyl transformation systems in the Gram-positive bacterium Rhodococcus sp. strain RHAl. Appl Environ Microbiol 61 4510-4513. 

Turner JN, Collins DN. 1983. Liver morphology in guinea pigs administered either pyrolysis products of a polychlorinated biphenyl transformer fluid or 2,3,7,8-tetrachlorodibenzo-p-dioxin. Toxicol Appl Pharmacol 67 417-429. 

Polychlorinated biphenyls (PCB) L S A Lubricants and hydraulic fluids Pesticides Plasticizer in paint and polymers Plasticizer (polymers) Transformer oils... 

PCBs and PCTs are particularly troublesome liquids because of their toxicity and persistence in the environment. They are defined as polychlorinated biphenyls, polychlorinated terphenyls, monomethyl-dibromo-diphenyl metliane, monomethyl-dichloro-diphenyl metliane or monomethyl-tetrachlorodiphenyl methane. With low electrical conductivity and heat resistance they found wide use as dielectric fluids and were formerly used as hydraulic fluids. PCBs have not been made in the UK since 1977 and whilst most new uses for the substance are banned in most countries, around two-thirds of the 1.5 million tonnes manufactured in Europe and the US prior to 1985 still remain in equipment such as transformers. PCTs have been used in the past in a restricted range of specialist industrial applications. 

PCB Polychlorinated biphenyls. Aka polychloro-biphenyls. Difficult to remediate chemical used in old-style transformers. Concentrated PCBs used to be referred to as "1268". 

Bedard DL, JE Quensen III (1995) Microbial reductive dechlorination of polychlorinated biphenyls. In Microbial transformation and Degradation of Toxic Organic Chemicals (Eds LY Yonng, CE Cemiglia), pp. 127-216. Wiley-Liss, New York. 

Bedard DL, RE Wagner, Ml Brennan, ML Haberl, RJ May, JF Brown Jr (1987b) Extensive degradation of Arochlors and environmentally transformed polychlorinated biphenyls by Alcaligenes eutrophus H 850. Appl Environ Microbiol 53 1094-1102. 

Bedard DL, (1990) Bacterial transformation of polychlorinated biphenyls. In Biotechnology and Biodegradation (Eds D Kamely, A Chakrabarty, GS Omenn), Vol. 4, pp. 369-388. Gulf Publishing Company, Houston. 

Silkworth, J., D. McMartin, A. DeCaprio, R. Rej, P. O Keefe, and L. Kaminsky. 1982. Acute toxicity in guinea pigs and rabbits of soot from a polychlorinated biphenyl-containing transformer fire. Toxicol. Appl. Pharmacol. 65 425-439. 

The water insoluble, highly chemically and thermally stable PCBs used as insulating fluids for transformers and capacitors, in paints, copy paper, etc., are extremely toxic, persistent in the environment and bioaccumulating. PCBs are currently destroyed by incineration of concentrates at high temperatures or chemically with sodium metals or organosodium. Both processes are costly. The cathodic reduction/elimination of the chlorine from polychlorinated biphenyl... 

Polychlorinated biphenyls (PCBs) were manufactured by catalytic chlorination of biphenyl to produce complex mixtures, each containing 60-90 different PCB molecular species or congeners (see Chaps. 1 and 4). In the United States, PCB mixtures were manufactured by Monsanto under the trade name Aroclor and were widely used as dielectric fluids in capacitors and transformers from 1929 to 1978. PCBs are widespread contaminants of aquatic sediments and continue to be a focus of environmental concern because they tend to accumulate in biota and are potentially toxic. The following sections show the most effective bioremediation techniques applied to various PCB contaminated environments ... 

Bedard, D.L., Wagner, R.E., Brennan, M.J., Haberl, M.L.,andBrown, J.F., Jr. Extensive degradation of Aroclors and environmentally transformed polychlorinated biphenyls by Alcaligenes eutrophus H850, Appl Environ. Microbiol,... 

The POCs include, but are certainly not limited to the polychlorinated biphenyls (PCBs) and the organochlorine pesticides, including those in current use, restricted use and historic use brominated flame retardants including polybrominated diphenyl ethers PAHs and the sometimes more toxic transformation products of these chemicals. Table 1 summarizes information on some of the POCs more commonly detected in alpine environments. 

Polychlorinated biphenyls (PCBs) are a family of compounds that were used extensively in electrical equipment, such as transformers, because of their insulating and heat transferring qualities. They are suspected human carcinogens and have been linked to liver, kidney, and other health problems. It is known that PCBs can be transported by air, and this is thought to be one of the major ways in which they circulate around the world, explaining why they are found in the Arctic and Antarctic. Indian women dwelling on Cornwall Island located in the Canadian portion of the reservation have elevated levels of toxic PCBs in their breast mUk. The PCB contamination does not appear to come from fish, but from air the women breathe every day [45]. 

Polychlorinated biphenyls (PCBs) are colorless toxic organic substances that cause cancer and birth defects. There are more than 200 different types of PCBs, ranging in consistency from heavy, oily liquids to waxy solids, and each type further varying in the number and location of chlorine atoms attached to its molecular carbon rings. They are fire resistant and do not conduct heat or electricity well. Accordingly they have numerous commercial applications as insulation in electrical systems, for example, for transformers. 

Polychlorinated biphenyls (PCBs), known by their trade marks of Arochlor (Monsanto U.S.), Phenochlor (in France), and Clophen (in Germany) are chemically similar to the chlorinated insecticides. Although not used for this purpose, their existence and persistence in the environment is well established. They were used to make more flexible and flame retardant plastics and are still used as insulating fluids in electrical transformers since there is no substitute in this application. They have been made by Monsanto since 1930 and were first discovered as a pollutant in 1966. U.S. production peaked at 72 million lb in 1970 but in 1975 it was down to 40 million Ib/yr because in 1971 Monsanto voluntarily adopted the policy of selling PCBs only for electrical systems. At least 105 PCBs are present in the environment. 

No observed adverse effect level Polychlorinated biphenyls - used as cooling agent in transformers because of low flammability. Now banned because of their environmental persistence and bioaccumulation in fat of many species including whales and humans... 

Polychlorinated biphenyls (PCBs) were once used extensively to fill electrical equipment, such as transformers and relays, but they are now banned because they are toxic when discharged to the environment. The basic biphenyl C12H10 is two benzene rings connected by a single bridge. 

The IT Corporation thermal destruction unit is a mobile unit that uses infrared incineration technology. The main objective of this process is to transform the feedstock into another form (an ash acceptable for delisting) while assuring safe discharge of exhaust gas products to the environment. The unit is capable of on-site remediation of wastes and soils contaminated with polychlorinated biphenyls (PCBs) and other organics. This technology is based on a conveyor belt furnace process. 

Kohler, H.-P. E., D. Kohler-Staub, and D. D. Focht, Cometabolism of polychlorinated biphenyls, enhanced transformation of Arochlor 1254 by growing cells , Appl. Environ. Microbiol., 54, 1940-1945 (1988). 

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