PCBs are a class of chemicals known as polychlorinated biphenyls. They are entirely man-made and do not occur naturally. They were first manufactured commercially in 1929 by Monsanto, their sole U.S. manufacturer. They were used in many different types of products including hydraulic fluid, casting wax, pigments, carbonless copy paper, plasticizer, vacuum pumps, compressors, heat transfer systems and others. Their primary use, however, was as a dielectric fluid in electrical equipment. Because of their stability and resistance to thermal breakdown as well as their insulating properties they were the fluid of choice for transformers and capacitors. As a matter of fact, because of their fire resistance, they were required by some fire codes.

During the 1970's, the health risks associated with PCBs became a major consideration due to several well publicized incidents. The most noted of these is known as the Yusho Incident. It took place in Japan when a rice oil plant had an equipment leak of PCB fluid into the product. The rice oil was sold and consumed resulting in many people being adversely affected.

Among the health affects of PCBs are skin ailments called chloracne, reproductive disorders, liver disease and  neurological problems in children. PCBs are a suspected human carcinogen and a known animal carcinogen. They are resistant to degradation and therefore persist for many years in the environment. Furthermore, they bioaccumulate in the foodchain and are stored in the body fat of animals and humans. Because of the health and environmental risks associated with PCBs, an Act of Congress, the Toxic Substances Control Act of 1976, directed the U.S. Environmental Protection Agency (EPA) to ban the manufacture of PCBs and regulated their use and disposal. EPA accomplished this by the issuance of regulation in 1978. The State of Connecticut, however, banned the manufacture of PCBs and began regulating them effective July 1, 1976. Both EPA and Connecticut, although banning their manufacture, allowed equipment containing PCBs to continue in use for the remainder of their useful lives.

PCB contamination from historic uses and dumping is widespread throughout the U.S. and the world. Disposal into waterways has caused PCB contamination of rivers, oceans, soils and even the polar ice cap. As a result, many forms of wildlife have become contaminated with PCBs. There have been bans on fishing in various locations. The U.S. Food and Drug Administration, as well as the Connecticut Department of Public Health, have issued advisories against eating certain fish. In addition, the U.S. EPA and the State of Connecticut have established maximum contaminant levels for PCBs in drinking water.

Additional PCB Information

PCB's in School Clocks and Municipal Buildings Webinar
On January 14, 2010, the Connecticut Department of Energy and Environmental Protection presented a webinar to school and municipal officials and health departments entitled, “PCB’s in School Clocks and Municipal Buildings”.  The purpose of this webinar was to raise awareness regarding the issue of PCB’s in School Clocks and other common items and materials and to present the opportunity for possible funding assistance to address such concerns.  View webinar

Common Uses of PCBs
History of Connecticut's PCB Program
Guide for Removal, Storage and Disposal of PCB Small Capacitors
PCB Capacitors in Gasoline Pumps
Caulk Guidance
Reporting a PCB Complaint
PCBs & Submersible Well Pumps
PCBs in Building Materials and Schools
Environmental Protection Agency (EPA) - PCB Information

Related Information

Connecticut's Fish Consumption Advisory and the Safe Eating of Fish Caught in Connecticut

For more information please contact the PCB Program at (860) 424-4177, e-mail the PCB Program or write to:

Department of Energy and Environmental Protection
Bureau of Materials Management and Compliance Assurance
Corrective Action Unit - PCB Program
79 Elm Street
Hartford, CT 06106-5127

Content Last Updated December 2023