Polychlorinated biphenyls properties

In earlier editions of the Eniyclopedia there have been articles covering the properties, manufacture, capacities, etc, of polychlorinated biphenyls (PCBs), chlorinated naphthalenes, benzene hexachloride, and chlorinated derivatives of cyclopentadiene. These materials are no longer in commercial use because of their toxicity. However, they stiU impact on the chemical industry because of residual environmental problems. Their toxicity and environmental impact are discussed (see Cm.OROCARBONSANDCm.OROHYDROCARBONS, TOXIC aromatics). 

PCBS (polychlorinated biphenyls) Toxic synthetic chemicals with excellent heat resistance and low electrical conductivity properties. Now little used but considerable quantities remain in old electrical equipment. Produces dioxins and polychlorinated dibenzo-furans when burned below 1200°C. PCBs are toxic and bio-accumulative. 

In general, capillary gas chromatography provides enough resolution for most determinations in environmental analysis. Multidimensional gas chromatography has been applied to environmental analysis mainly to solve separation problems for complex groups of compounds. Important applications of GC-GC can therefore be found in the analysis of organic micropollutants, where compounds such as polychlorinated dibenzodioxins (PCDDs) (10), polychlorinated dibenzofurans (PCDFs) (10) and polychlorinated biphenyls (PCBs) (11-15), on account of their similar properties, present serious separation problems. MDGC has also been used to analyse other pollutants in environmental samples (10, 16, 17). 

The polychlorinated biphenyls (PCBs) and polybrominated biphenyls (PBBs) are indnstrial chemicals that do not occur naturally in the environment. The properties, uses, and toxicology of the PCBs are described in detail in Safe (1984), Robertson and Hansen (2001), and Environmental Health Criteria 140. PBBs are described in Safe (1984) and Environmental Health Criteria 152. 

Furukawa K, N Arimura (1987) Purification and properties of 2,3-dihydroxybiphenyl dioxygenase from polychlorinated biphenyl-degrading Pseudomonas pseudoalcaligenes and Pseudomonas aeruginosa carrying the cloned bphC gene. J Bacterial 169 924-927. 

SFE is used mainly for nonpolar compounds [e.g. polychlorinated biphenyls (PCBs)]. Typically, small aliquots of soil (0.5-10 g) are used for extraction. The extraction solvent is a supercritical fluid, most commonly carbon dioxide, which has properties of both a liquid and gas. The supercritical fluid easily penetrates the small pores of soil and dissolves a variety of nonpolar compounds. Supercritical carbon dioxide extracts compounds from environmental samples at elevated temperature (100-200 °C) and pressure (5000-10 000 psi). High-quality carbon dioxide is required to minimize... 

In the past, mineral oil hydraulic fluids sometimes included additives such as polychlorinated biphenyls (PCBs) to improve the thermal resistance or other properties of the resulting fluids. These additives may present more toxicity risks than the primary ingredients of the hydraulic fluids. While such uses of PCBs have been discontinued, PCBs may be encountered as components of hydraulic fluids at NPL sites contaminated by hydraulic fluids (ATSDR 1993b). 

Burkhard, L.P. (1984) Physical-Chemical Properties of the Polychlorinated Biphenyls Measurement, Estimation, and Application to Environmental Systems. Ph.D. Thesis, University of Wisconsin-Madison, Wisconsin. 

Dunnivant, F. M., Elzerman, A. W., Jurs, P. C., Hansen, M. N. (1992) Quantitative structure-property relationships for aqueous solubilities and Henry s law constants of polychlorinated biphenyls. Environ. Sci. Technol. 26, 1567-1573. 

Kamlet, M. J., Doherty, R. M., Carr, P. W., Mackay, D., Abraham, M. H., Taft, R. W. (1988) Linear solvation energy relationships. 44. Parameter estimation rules that allow accurate prediction of octanol/water partition coefficients and other solubility and toxicity properties of polychlorinated biphenyls and polycyclic aromatic hydrocarbons. Environ. Sci. Technol. 22, 503-509. 

Metcalfe, D.E., Zukovs, G., Mackay, D., Paterson, S. (1988) Polychlorinated biphenyls (PCBs) physical and chemical property data. In Hazards, Decontamination and Replacement of PCB A Comprehensive Guide. Crine, J.P., Ed., pp. 3-33, Plenum Press, New York. 

In summary, it would appear that rainbow trout are responsive to cytochrome P -450-type inducers (e.g. planar polychlorinated biphenyls and polycyclic aromatic hydrocarbons), but are not responsive to cytochrome P-450-type inducers (e.g. phenobar-bital and non-planar polychlorinated biphenyls). Although induced rainbow trout hemoprotein(s) P-450 show high activity with cytochrome P -450 substrates, the induced hemoprotein at 57,000 daltons appears, in electrophoretic and spectral properties, to differ from rodent cytochrome P -450. 

The applicability of using these interdisciplinary approaches, which include incorporation of various physical and chemical properties of the pollutants, QSARs/QSPRs and multicomponent joint action modeling are discussed and evaluated using a group of toxic and carcinogenic pollutants, i. e., polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). 

The second structural property described by the 4ypc index is the substitution pattern on the benzene ring. The value of the 4ypc index increases sharply with the degree of substitution, while in the isomeric classes of substituted benzenes it increases with the proximity of substituents. Thus, this structural parameter has also been found to be very useful in describing activities and properties of polysubstituted benzenes [103], chlorinated benzenes [279], and polychlorinated biphenyls [286]. 

Shiu, W.Y. and Ma, K.C. 2000, Temperatrrre dependence of physical-chemical properties of selected chemicals of envirorrmental interest. II. Chloroberrzenes, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxirrs, and dibenzofurarrs. J. Phys. CherrL Ref. Data 29 387-462. 

Brunner, S., Hornung, E., Sand, H., Wolf, E., Piringer, O.G., Altschuh, J., andBriiggemann, R. Heniy s law constants for polychlorinated biphenyls experimental determination and structure-property relationships. Environ. Sci. Technol, 24 (11) 1751 -1754,1990. 

The technology primarily treats clays because their physical and chemical properties, such as external and internal active surfaces produced by their fine crystalline structure, make them difficult to decontaminate. ARC asserts that pilot studies showed that the technology works well on perchloroethylene (PCE), xylene, phenols, and polychlorinated biphenyls (PCBs). 

POLYCHLORINATED BIPHENYL (PCB)a PERMEATION RATE PROPERTIES FOR PROTECTIVE GARMENT MATERIALS... 

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