Polychlorinated biphenyl (PCB) is an organic chlorine compound once used in a variety of industrial applications and electronics. PCBs are still found in transformers and other equipment containing oil or hydraulic fluid mixed with PCBs.
 
PCBs are considered a significant environmental pollutant and carcinogen. PCB and PCB-derived substances can remain in the environment for many years and travel up the food chain.
 
Equipment containing materials with 50 ppm or greater PCBs are regulated under the federal Toxic Substance Control Act (TSCA) and are required to carry a warning label. Spills and leaks of fluids containing more than 50 ppm PCBs must be reported to EHS. EHS must also be contacted before draining or removal of equipment known or suspected to contain PCBs.
 
To avoid risk of PCB exposure, always wear appropriate personal protection equipment when handling oil-containing equipment.