Polychlorinated biphenyls, more commonly known as PCBs, are so hazardous that the United States government banned their usage in 1977.  Most people associate PCBs with oils used to cool industrial electrical transformers, and do not realize that some common caulking materials used in American buildings contained PCBs, until they were banned in the late 1970s.  The United States Environmental Protection Agency (USEPA), considers PCBs found in concentrations greater than fifty (50) ppm as hazardous.

The existence of PCBs-based caulking materials in American buildings of all types and sizes is fairly common, with one study by the Harvard School of Public Health finding PCBs-based caulking materials that exceed the USEPA fifty (50) ppm limit in one-third of the buildings examined.  Furthermore, the study found elevated PCBs levels in air samples both within the rooms of the buildings that contained PCBs-based caulking materials and the building’s ventilation systems.

The conclusion of the study is that buildings built or refurbished prior to 1977 might contain PCBs-based caulking materials, and testing of caulking materials within these buildings is warranted based on public health concerns.  Caulking materials are not  commonly tested for PCBs when an environmental investigation is being conducted within a building.  Based on the results of this study, it appears that testing of caulking materials for PCBs by a certified environmental professional and laboratory, especially in buildings constructed before 1977, is a prudent measure to ensure the health and safety of the building occupants, and can assist in estimating demolition costs, if necessary.  In some cases, encapsulation or removal of the PCBs-based caulking materials might be necessary to protect inhabitants.