What are polychlorinated biphenyls (PCBs)?

Polychlorinated biphenyls, commonly called PCBs, are mixtures of up to 209 chlorinated compounds that do not occur naturally. PCBs are either oily liquids or waxy solids that are colorless to light yellow. They have no taste or smell. 

U.S. production of PCBs stopped in 1977 because of suspected harmful health and environmental effects; exports and imports of PCBs stopped in 1979. Before 1977, PCBs were used as insulation, coolants, and lubricants in transformers, capacitors, vacuum pumps, gas-transmission turbines, hydraulic fluids, and other electrical equipment; as fillers in casting waxes; as plasticizers in paints, plastics, and rubber products; and in surface coatings, sealants, caulking compounds, fire retardants, dedusting agents, glues, inks, pesticides, and carbonless copy paper. Products made before 1977 that may still contain PCBs include old fluorescent lights, electrical devices, and microscope hydraulic oils.

You can be exposed to PCBs by breathing air that contains them, swallowing contaminated food or water, or touching products that contain them. 

Exposure to PCBs that entered the air, water, and soil during their use can occur because they remain in the environment for very long periods of time. You can be exposed to PCBs by using or being near older equipment and products that still contain PCBs, including electrical transformers, capacitors, fluorescent lighting fixtures, and appliances. You can also be exposed by eating contaminated fish, particularly sportfish from lakes and rivers, and game animals which have fed on smaller species in which PCBs have accumulated. 

You can be exposed to PCBs by breathing air from hazardous waste sites, illegal or improper disposal of industrial wastes and consumer products, some incinerators, and leaks or fires in electrical transformers and other products containing PCBs; and by drinking well water that is contaminated with PCBs. 

At work, you can be exposed to PCBs during the repair and maintenance of transformers that contain PCBs; from accidents, fires, or spills involving PCB transformers and older electrical equipment; and through the disposal of PCB materials. Exposure at work can occur if you work at a hazardous waste site where PCBs have been deposited and remain in the soil; or if you work in electric cable repair, electroplating, emergency response, firefighting, heat exchanging equipment repair, metal finishing, paving, roofing, pipefitting, plumbing, timber product manufacturing, and waste oil processing.

Swallowing large amounts of PCBs can cause coma and death. 

PCBs are listed as "reasonably anticipated to be human carcinogens" in the Eleventh Report on Carcinogens published by the National Toxicology Program, because they have been linked to increased rates of liver and skin cancers. 

Long-term exposure to PCBs may have serious effects on the liver, immune system, endocrine system, reproductive system, and thyroid hormone levels, which in turn may affect normal growth and development. Exposure may damage the nervous system, causing headaches, numbness, weakness, and tingling in the arms and legs; it may also cause learning deficits and changes in activity. 

If you are pregnant, exposure to PCBs can cause miscarriage or decreased birth weight in babies. Babies born to and nursed by women exposed to PCBs can have abnormal responses in tests of infant behavior, such as trouble with motor skills and short-term memory loss; immune system problems; and developmental abnormalities. 

Short-term exposure to PCBs can irritate and burn the eyes, lungs, nose, and throat. It can cause coughing, difficulty breathing, nausea, vomiting, weight loss, depression, fatigue, sweating at the palms, jaundice, headache, dizziness, nervousness, muscle and joint pain, discoloration of fingernails, arthritis, and stomach pain. In women, short-term exposure can cause irregular menstrual cycles. 

Skin contact with PCBs may cause an acne-like skin rash, which can last for years. 

Nursing infants, fetuses, and people with liver disorders and skin diseases are most susceptible to the human health effects of PCBs. Drinking alcohol can increase the liver damage caused by PCBs. 

If you think your health has been affected by exposure to PCBs, contact your health care professional.

For poisoning emergencies or questions about possible poisons, please contact your local poison control center at 1-800-222-1222.

Locations where Polychlorinated Biphenyls may be found
City	Farm	Town	U.S.-Mexico Border	Port
Brownfield Construction Drinking Water Factory Homes Hospital Offices and Stores River School	Barn and Silo Chemical Storage Tank Drinking Water Homes Landfill Shed	Drinking Water Factory Homes Offices and Stores River School	Auto Shop Drinking Water Homes Illegal Dumps and Tire Piles Maquiladora River Stormwater and Sewage Trash Burning	Chemical Storage Tank Coastal Brownfield Cruise Ship Drinking Water Fuel Pipelines Homes Marina and Boats Offices and Stores River Shellfishing Shipping Shipyard Storms and Floods Stormwater and Sewage Urban and Industrial Runoff

Last Updated: September 08, 2008