PCBs (Polychlorinated biphenyls)

By Jayne Mathis

What are PCBs?

According to the CDC, PCBs are "Polychlorinated biphenyls are mixtures of up to 209 individual chlorinated compounds (known as congeners)... PCBs have been used as coolants and lubricants in transformers, capacitors, and other electrical equipment because they don't burn easily and are good insulators"(3). They have been banned from product use since the '70s, but can still be found in many places as waste from factories.

Why are PCBs dangerous?

The CDC tells us "The most commonly observed health effects in people exposed to large amounts of PCBs are skin conditions such as acne and rashes. Studies in exposed workers have shown changes in blood and urine that may indicate liver damage... Other effects of PCBs in animals include changes in the immune system, behavioral alterations, and impaired reproduction. PCBs are not known to cause birth defects... Few studies of workers indicate that PCBs were associated with certain kinds of cancer in humans, such as cancer of the liver and biliary tract. Rats that ate food containing high levels of PCBs for two years developed liver cancer. The Department of Health and Human Services (DHHS) has concluded that PCBs may reasonably be anticipated to be carcinogens... Some of these behaviors, such as problems with motor skills and a decrease in short-term memory, lasted for several years. Other studies suggest that the immune system was affected in children born to and nursed by mothers exposed to increased levels of PCBs. There are no reports of structural birth defects caused by exposure to PCBs or of health effects of PCBs in older children"(3). Simply put, PCBs can cause liver and skin problems, temporary impairments of children nursing from an exposed mother, and in some extreme cases cause cancer. It's definitely not something to mess around with.

Where can PCBs be found?

The CDC says they can be found in "old fluorescent lighting fixtures and electrical devices and appliances, such as television sets and refrigerators, that were made 30 or more years ago. These items may leak small amounts of PCBs into the air"(3). You can also get PCBs by "Eating contaminated food. The main dietary sources of PCBs are fish (especially sportfish caught in contaminated lakes or rivers), meat, and dairy products...air near hazardous waste sites and drinking contaminated well water"(3) and "In the workplace during repair and maintenance of PCB transformers; accidents, fires or spills involving transformers, fluorescent lights, and other old electrical devices; and disposal of PCB materials"(3). So, you need to be careful with old electronics and wild game, just in case they have the toxins in them.

How are PCBs being kept out of the environment?

These are the regulations for air, water, and food exposure to PCBs by the OSHA, EPA, and FDA:

  • "The Occupational Safety and Health Administration (OSHA)’s permissible exposure limit (PEL) is a timeweighted average (TWA) airborne concentration of 1.0 milligrams per cubic meter (mg/m^3 ) for PCBs containing 42% chlorine"
  • "EPA’s goal for drinking water’s maximum contaminant level is zero, and the enforceable MCL for PCBs in public water systems is 0.0005ppm [mg/L]."
  • "FDA mandates tolerances of 0.2–3.0 ppm PCBs for all foods, with a tolerance level in fish of 2 ppm. FDA also limits PCBs in paper food-packaging materials to 10 ppm [mg/L]" (1)

How do I make sure I'm safe?

There are many guidelines about PCBs. The CDC says "Certain states, Native American tribes, and U.S. territories have issued advisories to warn people about PCB-contaminated fish and fish-eating wildlife. You can reduce your family's exposure to PCBs by obeying these advisories"(3). They also advise that " Chidren should be told not play with old appliances, electrical equipment, or transformers, since they may contain PCBs...Children should be discouraged from playing in the dirt near hazardous waste sites and in areas where there was a transformer fire. Children should also be discouraged from eating dirt and putting dirty hands, toys or other objects in their mouths, and should wash hands frequently"(3) and "If you are exposed to PCBs in the workplace it is possible to carry them home on your clothes, body, or tools. If this is the case, you should shower and change clothing before leaving work, and your work clothes should be kept separate from other clothes and laundered separately"(3). It doesn't seem like much, but it'll help you for sure in the long run.


  1. "ATSDR Case Studies in Environmental Medicine Polychlorinated Biphenyls (PCBs) Toxicity." CDC. ATSDR, 14 May 2014. Web. 10 Apr. 2015.
  2. "Toxic Substances Portal - Polychlorinated Biphenyls (PCBs)." CDC. ATSDR, n.d. Web. 6 Apr. 2015.