What Are PCBs and Why Are They Dangerous?
Posted on Tue, Aug 25, 2009 @ 02:05 PM
By Jason Atwood, Field Services Manager
PCBs, or Polychlorinated Biphenyls, are a group of toxic, man-made chemicals produced by the chlorination of Biphenyl. They range from light, oily fluids to heavy, greasy or waxy textures. From 1929-1979 PCBs were manufactured in the United States; they were used often in high-voltage electrical transformers because they conducted heat well while being fire-resistant and great insulators. However, in 1979 the EPA banned the manufacture of PCBs because they were discovered to be highly toxic and a potent carcinogen. Today, any hazardous waste that contains more than 50 parts per million of PCBs are subject to regulation under the Toxic Substances Control Act.
Why are PCBs Dangerous?
PCBs can be detrimental to human health. Scientists have found PCBs to cause cancer in animals, and to adversely affect the immune system, reproductive system, endocrine system, and nervous system. PCBs can be absorbed by inhalation or skin contact. This is not the worst of it though. Scientists are most concerned with PCBs’ ability to bio-accumulate, or buildup contaminants in an organism's tissues (as is the case with mercury and other heavy metals).
Where can be PCBs Found?
Since PCBs allow for flexibility and pliability, they were used widely as an additive to caulking materials in the decades during which they were produced. As a result, PCBs are commonly encountered in the window caulking and/or mansonry expansion joint caulking of older buildings. Compounding the problem is that as the caulking deteriorates over years of weathering, the PCB compounds leach into adjacent non-PCB containing materials causing wide spread cross contamination. As the caulk ages and weathers (appears brittle, cracked, or peeled), it becomes increasingly dangerous because it is releases an increased amount of PCBs. Exposure may occur when the impacted caulking comes into contact with brick, concrete, wood, or any other porous material that surround the joints. If the caulking is on the exterior of a building, PCBs may also leach and penetrate the surrounding soil.
How do I manage PCBs if they are encountered?
Firstly, if your office or school was built prior to 1979 and you believe it may have PCB impacted caulking, you can have the materials of concern analyzed and tested by a environmental consulting company – Triumvirate can assist in guiding you through this process. If the lab analytical results demonstrate that PCBs are present, exposure to the areas of concern should be limited. Usually, PCB poses the largest concern for buildings during renovation or construction as testing of the material is required prior to disruption or removal of suspect material. Triumvirate has a broad base of experience with management techniques should contamination be encountered. Frequently, the most effective means of remediation include removal of the impacted caulking by appropriately trained personnel through manual techniques and licensed off site disposal. Other options including decontamination of non-porous surfaces, encapsulation of contaminated areas that cannot be removed, and excavation and off site disposal of soil that may have been affected by leaching of the impacted material. The process of testing, planning, and implementation can be daunting given the complexity of the issue, however relying on the knowledge and expertise of an industry professional can make this process far less formidable!