For about 50 years, polychlorinated biphenyls (PCBs) were commonly used in industrial
materials including, caulking, cutting oils, inks, paints and as dielectric fluids in electrical
equipment such as transformers and capacitors. Concerns over health effects led to a North
American ban of manufacturing PCBs in 1977. By the mid-1980s, an initiative was started to
clean up contaminated areas and to phase out PCB-containing equipment and products that
were still in use. This cleanup effort continues today.