Transformer Oils Potential for PCBs Contamination

Polychlorinated biphenyls (PCBs) were commercially produced world-wide on a large scale between the 1930s and 1980s that had been used widely in variety of commercial equipment like transformers, capacitors and other electrical equipment because of their useful quality as being a fire retardant. But due to their persistence and ubiquitous distribution in the environment, PCBs were banned from the U.S in the 1970s and internationally through the Stockholm Convention on Persistent Organic Pollutants. Although banned by law and punished heavily, large numbers of PCB-contaminated transformers are still in service. Thus, there remains a huge reservoir of PCBs with the potential to serve as sources of contamination to the environment. In this study, using EN 12766 test method: “Petroleum products and used oils-Determination of PCBs and related products”, PCBs were analyzed in the random samples collected from different regions of Turkey. The samples also used for screening for the presence of total halogens and chlorine. Test results of the study showed that PCBs were present in certain transformers but concentrations in the most of samples did not exceed the limit value of 50 ppm. However, there was a significant relationship between the PCB concentrations and the halogens. Finally, the contaminated transformer oils were evaluated according to Regulation on Control of Waste Oils, published in the Official Gazette 2008/26952.