Chlorinated biphenyls

Chlorinated biphenyls, chlorinated naphthalenes, benzene hexachloride, [608-73-17, and chlorinated derivatives of cyclopentadiene are no longer in commercial use because of their toxicity. However, they still impact on the chemical industry because of residual environmental problems. This article discusses the toxicity and environmental impact of these materials. 

Hexachlorobiphenyl Biphenyl chlorinated to a chlorine content of 60 weight percent 60 45... 

Ballschmiter, K., R. Bacher, A. Mennel, R. Fischer, U. Riehle, and M. Swerev, The determination of chlorinated biphenyls, chlorinated dibenzodioxins, and chlorinated dibenzofurans by GC-MS , J. High Res. Chromatogr., 15,260-270 (1992). 

The large number of potential congeners and isomers of some semivolatile compounds is illustrated in Table 8.1 which shows the numbers of possible chlorinated biphenyl, chlorinated dibenzo-/ -dioxin, and chlorinated dibenzofuran congeners and isomers. The total number of chlorinated congeners of each parent compound is the sum of the possible isomers at each level of chlorination. Dibenzofuran has more possible chlorinated congeners and isomers than chlorinated dibenzo-/ -dioxin (Fig. 8.2) because it has just one ring oxygen and a less symmetrical structure. If F, Br, I, CH3 or any other uniform... 

TABLE 8.1. The Number of Possible Chlorinated Biphenyl, Chlorinated Dibenzo-p-dioxin, and Chlorinated Dibenzofuran Congenors and Isomers... 

Polychlorinated Biphenyl Chlorinated Biphenyl Halogenated Waxes PCB Polychloro- Polyphenyls ... 

SYNONYMS Aroclor, chlorinated biphenyl, chlorinated diphenyl, PCBs, phenoclor. 

Figure 5.18 Relation between the excretion rate constant ( 2) and octanol-water partition coefficient (ATd,oct) for polyhalogenated hydrocarbons chlorinated dibenzofurans O, chlorinated dibenzodioxins O, brominated biphenyls T, chlorinated naphthalenes , brominated benzenes , chlorinated biphenyls , chlorinated benzenes. [Reproduced with permission from A. Opperhuizen and D. T. H. M. Sijm, Environ. Toxicol. Chem. 9, 175 (1990). Copyright SETAC, Pensacola, FL, USA.]...

Synonyms cas 1336-36-3 aroclor chlopen chlorextol chlorinated biphenyls chlorinated... 

Synonyms Biphenyl, chlorinated 1,1 -Biphenyl, chloro derive. Biphenyl chloro dervis. Chlorinated biphenyl PCBs... 

This study was undertaken to test the ability of our previous molecular connectivity models to accurately predict the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of polycyclic aromatic hydrocarbons (PAHs), alkylbenzenes, alkenylbenzenes, chlorobenzenes, polychlorinated biphenyls, chlorinated alkanes and alkenes, heterocyclic arid substituted PAHs, and halogenated phenols. Tests performed on large groups of such compounds clearly demonstrate that these simple nonempirical models accurately predict the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of the above compounds. Moreover, they outperform traditional empirical models based on 1-octanol/ water partition coefficients or water solubilities in accuracy, speed, and range of applicability. These results show that the molecular connectivity models are a very accurate predictive tool for the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of a wide range of organic chemicals and that it can be confidently used to rank potentially hazardous chemicals and thus to create a priority testing list. ... 

The purpose of this chapter is to provide the reader with robust, easily applied methods for estimating diffusivities within the dominant natural phases (air, water, solid matrix, oil, etc.) for a range of environmentally and geochemically relevant compounds. The types of compounds considered include atomic (Hg) and diatomic (O2, CI2) elements, simple molecules (H2S, CO2, NO), organic contaminants (polynuclear aromatic hydrocarbons, polychlorinated biphenyls, chlorinated solvents), as well as dissolved cationic (Pb +, Cr +) and anionic (Br , SO ) species. Examples showing the application of estimation methods are provided and the results of different methods are compared to measured values from the literature. When available, estimates regarding the accuracy of theoretical and empirical methods are included. Experimental methods for determining diffusivities in air, water, porous... 

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