Askarel

Transformers filled with Askarel which contained a significant percentage of PCBs combined with other fluidizers. 

ASTM standard method D2283-86 defines the Askarel mixtures used by the utility industry (Table 5). The result of retrofilling older Askarel transformers is the presence of trace PCBs in refurbished oil filled equipment. McGraw [369]... 

Table 5. Askarel components in weight percent (after ASTM [367])... 

ASTM (1986) Chlorinated aromatic hydrocarbons (Askarels) for transformers. D228386. Annual book of ASTM standards, vol 10.03. American Society for Testing of Materials, Philadelphia, PA, 19103... 

Larsen, B., Skejo-Andreasen, H., Paya-Perez, A. (1992) octanol-water partition coefficients of 39 polychlorinated biphenyls in Askarel mixture. Fresenius Environ. Bull. l(Suppl), S13-S18. 

Of 55 transformer workers who were exposed to Askarel PCBs (0.00001-0.012 mg/m ) for a mean duration of 3.75 years, 2 gave a history of removal of a melanoma (type not reported) (Emmett et al. 1988a). No melanomas were reported by 56 age-matched nonexposed subjects, and the difference between the groups was not statistically significant. 

Finally, after discussing the history of how PCBs have been used in industry, one panelist recommended that the profile mention the different chemicals, such as chlorobenzenes, that are commonly found in PCBs. This suggestion followed an observer comment on past use of Askarels—a generic grouping of non-combustible electrical fluids that contained PCBs and often, though not always, contained chlorobenzenes. Also relevant to this discussion was the observation that many companies altered the composition of PCB mixtures that were originally prepared by manufacturers. 

Askarel A general term for a group of nonflammable, synthetic, chlorinated, aromatic hydrocarbons used as electrical insulating media. 

Pure PCBs are white crystalline solids, but PCBs are often liquid because of impurities. Because of the need for this dielectric fluid to transfer heat, PCBs were often diluted with chlorinated benzenes to yield askarels, which are less viscous (Durfee et al., 1976 MUler, 1982). While PCBs are no longer manufactured, they continue to be released into the environment. 

Askarels. Askarels are mixtures of many isomer groups of PCBs and chlorobenzenes and may also contain phenoxypropene oxide or diepoxide. They are mainly used as transformer oils and are of many types, namely, A, B, C, D, E, F, and G. Physical properties of some askarels are shown in Tables 36.6 and 36.7. 

There were 11,505 tons of askarel in use, 9,649 tons of which were in transformers, 1,697 tons in capacitors, and 159 tons in other equipment. 

When human exposures are likely, protective respiratory equipment should be used. Table 36.8 shows the distribution and fate of an Aroclor 1248 spill after 30 days (NCR, 1979). It is interesting to note that most askarels spilled on land end up in the sou, while the bulk of askarels spilled on water wUl eventuaUy be adsorbed onto the sediments. 

The two worst-case histories of a PCB spill and a fire are presented here. These exemplify some aspects of the behavior and environmental fate of PCBs as described in the previous sections. A number of small spills of PCBs and askarels have been deseribed in Garrett (1983). 

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