Transformer fluid

The five largest uses for PCBs prior to 1970 were dielectric fluids in capacitors, plasticizers, lubricants, transformer fluids, and hydraulic fluids. They were also used widely in protective coatings, sealers, putty, grinding fluids, printing inks, pattern waxes, carbonless paper, etc. (see Chap. 1). Because of this widespread PCB use they are found throughout the environment [363-365]. A number of important properties of PCBs are discussed below along with information on their distribution and persistence in the environment. 

Hydrophobic pollutants such as PCBs often partition into lipid rather than into water. The K0w measures this partitioning. This coefficient provides an indication of the degree to which a pollutant accumulates into fatty tissues and any organic phase. This coefficient is especially useful for determining the release of PCBs from mineral oil transformer fluids, and Hawker and Connell [391] pro-... 

Girvin et al. [358] evaluated the release of PCBs from electrical substation soils contaminated with transformer fluids. They observed that there are two phases to the uptake and release of PCBs with these soils. The initial phase is a rapid, labile phase that is followed by a slower, nonlabile phase. The labile phase occurs at a scale of hours to days while the nonlabile phase releases over weeks and months. Girvin et al. [422] also reviewed the effects of adsorption on the mobility of PCBs and their transport. In an example presented for a hexa-chlorobiphenyl, these authors noted that the PCB isomer would have a retardation factor Rf of 1400 for the particular case given. This means that the ground-... 

Figure 12. Principal Components Plot from Five Aroclors Classes and a Used Transformer Fluid (most similar to Aroclor 1260).

Figure 13. Fractional Composition Histograms of Used Transformer Fluid and Aroclors.

DDT and polychlorobiphenyl (PCB) transformer fluids, have been phased out in most countries because of their apparent interference with the reproductive cycles of birds and mammals. 

Biodegradation no reduction of concentration in the spilled transformer fluid contaminant of Aroclor was detected over a two-year period (Moein et al. 1976 quoted, Pal et al. 1980). 

DeCaprio AP, McMartin DM, O Keefe PW, et al. 1986. Subchronic oral toxicity of 2,3,7,8-tetrachloro-dibenzo-p-dioxin in the guinea pig Comparisons with a PCB-containing transformer fluid pyrolysate. Fundam Appl Toxicol 6 454-463. 

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. 

The production of PCBs and use of PCB formulations are possible sources of PCDEs. PCDEs have been measured in a PCB transformer fluid, which contained 51 % of Aroclor 1260 [50]. The production and use of PCBs has been quite extensive but, since there are no figures on the concentrations of PCDEs in PCB formulations, one cannot estimate their role as a source of PCDEs. 

Hexachlorobutadiene is an industrial by-product of tetrachloroethylene, trichloroethylene, and perchloro-ethylene production and is used as a solvent for elastomers, heat transfer liquids, transformer fluids, and hydraulic fluids. Hexachlorobutadiene may still be used in certain countries as a fumigant. It is also released during refuse combustion and is found in fly ash. 

Origin / Industry Sources/Uses Prepared by the chlorination of biphenyl used in the electrical industry in capacitors and transformers used in the formulation of lubricating and cutting oils pesticides adhesives plastics inks paints sealants. Exposure Routes Inhalation of fume or vapor percutaneous adsorption of liquid ingestion eye and skin contact landfills containing PCB waste materials and products incineration of municipal refuse and sewage sludge waste transformer fluid disposal to open areas. 

Analysis was for all workers in the transformer plant, with definite , probable , or possible link between death and pancreatic cancer. The definite pancreatic cancer mortality cases yielded an SMR of 2.92 (95% Cl=1.17-6.01). Among all workers employed for 6 months (n=812) an SMR of 7.64 (3.29-15.06) was obtained, and among workers employed for 6 months in the transformer assembly department (n=308), an SMR of 12.9 (2.59-37.7) was calculated. The authors noted that considerably more exposure to mineral oils occurred than exposure to PCB-containing askarol transformer fluids. Wong (1995) identified other concerns about the positive pancreatic findings, including inclusion of cases that had neither sufficient duration of exposure nor sufficient latency to be related to PCB exposure at the plant. 

Statistically non-significant SMRs were obtained in separate analyses for non-Hodgkins lymphomas and leukemias in all workers employed for 6 months (n=812) and in transformer assembly workers employed for 6 months (n=308). The authors noted that considerably more exposure to mineral oils occurred than exposure to PCB-containing askarol transformer fluids. 

Transformer fluid Circuit boards Drain cleaners Leather finishing Dyes... 

MV across electrodes 50 mm apart without breakdown, and at 10 bars it is used for high-power underground electrical transmission systems at 400 V and above. However, there is now some environmental concern at its use as an electrical transformer fluid and as an inert blanketing gas in magnesium metal casting, since even minute amounts may contribute to an atmospheric greenhouse effect (it is 6800 times as potent as CO2). 

PCBs were developed as dielectric fluids (first manufactured by Monsanto in 1929). The fluids display low reactivity, high electrical resistance, and are stable when exposed to heat and pressure. Based on these highly desirable chemical and physical characteristics many applications such as transformer fluids, Are retardants, hydraulic fluids, plasticizers, adhesives, and many others were developed. 

The import certification regulation currently exempts imported articles themselves, but chemical substances and mixtures in an article that are intended to be removed or released from the article, and have an end use or commercial purpose separate from the article of which they are a part, are subject to import certification requirementsT An example of a chemical substance or mixture that is intended to be released from the article and has a separate end use than the article would be ink in pens. Conversely, transformer fluids in transformers, lighter fluids in cigarette lighters, and crankcase oil in automobiles are not intended to be removed from the articles of which they are a part and have no commercial purpose separate and apart from these articles, and so would not need import certificates. Those same chemical substances, if imported in drums, cans, or other containers, are subject to import certification requirements." ... 

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