Polychlorinated biphenyls (PCBs) are man-made chemicals that persist in the environment and were widely used in construction materials and electrical products prior to 1978. PCBs can affect the immune system, reproductive system, nervous system and endocrine system and are potentially cancer-causing if they build up in the body over long periods of time. Congress banned manufacture and use of PCBs in 1976 and they were phased out in 1978 except in certain limited uses.

To read more about EPA-issued guidance, click here for more information.