Polychlorinated Biphenyls (PCBs)

PCBs are a group of man-made chemicals which have no known taste or smell and range in consistency from an oil to a waxy solid. PCBs were manufactured in the United States from 1929 until a ban was put in place in 1979. PCBs were used in hundreds of industrial and commercial applications due to their non-flammability, chemical stability, high boiling point, and electrical insulating properties.  

Although no longer commercially produced in the United States, PCBs may be present in products and materials produced before the 1979 ban. Some products that may contain PCBs include: 

  • Transformers, capacitors, and other electrical equipment 
  • Oil used in motors and hydraulic systems 
  • Fluorescent light ballasts 
  • Adhesives and tapes 
  • Oil-based paint 
  • Caulking 
  • Plastics 
  • Floor finish
What health effects are associated with PCBs?
PCBs are one of the most broadly studied groups of environmental contaminants and are known to have various adverse health effects on humans. Studies in humans and/or animals show that exposure to PCBs is associated with toxic effects including liver, thyroid, dermal and ocular changes, immunological alterations, neurodevelopmental changes, reduced birth weight, and reproductive toxicity. Animal studies show that ingesting PCB mixtures can cause liver and thyroid cancers. Increased cases of liver cancer and other types of cancers have also been observed in human populations who were exposed to PCBs occupationally or accidentally. Because children’s brain, nervous system, immune system, thyroid, and reproductive organs are still developing, they may be more susceptible than adults to adverse health effects from PCBs. 

For more information about PCB exposure and health, visit the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQ page.

How might I come into contact with PCBs?

Due to past uses and disposal, and because they break down very slowly, PCBs are widespread in our environment and food chain. As such, most individuals have been exposed to PCBs at one time or another.  

Food – Food is generally considered the most common way individuals are exposed to PCBs. PCBs can be found in meat, eggs, fish, and dairy products. The Connecticut Department of Public Health issues a yearly advisory for reducing fish consumption when fish tissue contains unsafe levels of PCBs or other chemicals. For more information about the Connecticut fish advisory and guidelines for safe consumption of fish, please visit our Fish Consumption Advisory webpage. 

Buildings – Indoor air may have higher than average levels of PCBs in buildings that have electrical devices and/or materials containing PCBs. As they break down or are disturbed, PCB-containing building materials and electrical products can produce vapors or dust. Occupants may be exposed by skin contact with these materials or products, unintentional ingestion via hand-to-mouth contact, or by inhaling PCB-laden dust or vapors.  


Additional Resources

PCBs General Information

Information for Schools and Teachers About PCB-Contaminated Building Materials