Posted on Thu, Dec 10, 2009 @ 10:56 AM
By Kristina Florentino, Environmental Compliance Specialist
An emerging environmental health issue is information published by the Environmental Protection Agency (US EPA) that caulk containing polychlorinated biphenyls (PCB) was used in many nonresidential buildings, including schools, throughout the 1950s through the 1970s. PCBs are man-made toxic chemicals that persist in the environment and bioaccumulate in animals and humans. Exposure to PCBs can affect the immune system, reproductive system, nervous system, and endocrine system and is potentially cancer-causing. Caulk is used in construction to seal gaps to make windows, door frames, masonry and joints in buildings watertight or airtight. Before the prohibition of PCBs in all U.S.-manufactured products in 1977, caulk was prepared with PCBs due to the flexibility and other valuable properties of the compound such as persistence and low reactivity. Buildings that were constructed or renovated during this period could contain caulking with elevated levels of these hazardous compounds.
Until recently, testing was seldom conducted for PCB levels and there have been few studies to determine the environmental exposures to building occupants, remediation or construction workers, or related environmental contamination. The material will evidently deteriorate and leach PCBs into nearby soil, concrete pads, bricks, mortar, storm drains and potentially volatilize. Studies have shown a correlation between PCBs in caulking and elevated levels of PCBs in indoor air and dust, in addition to ambient soil surrounding the buildings. The deteriorating caulk has the highest potential for creating dust exposing occupants via inhalation. In addition to inhalation from PCBs in the air or dust, dermal exposure may occur when a person comes in contact with the caulk, surrounding porous materials, or PCB-contaminated soil adjacent to buildings.
The US EPA recommends indoor air monitoring to determine if PCB levels exceed the suggested public health levels. If testing reveals PCB levels above these levels, the potential sources of PCBs need to be identified. Typically testing of samples of caulk, dust, and soil is performed. If elevated air levels of PCBs are found, it is also recommended that the ventilation system be evaluated to determine if it is contaminated with PCBs, since it may have been contaminated before other sources of PCBs were removed from the building and may be contributing to elevated air levels. Contaminated ventilation systems need to be decontaminated along with removal of any sources of PCBs that are found to avoid recontamination of the system.
EPA is currently researching PCB exposure related to contaminated caulk and looking into methods for mitigating exposure and potential risks associated with PCBs in caulk. In addition to the risk posed by PCBs caulk can also contain as much as 20 percent asbestos, requiring additional management during sampling and disposal.
Resources: MA DEP PCB Q&A, US EPA, Target Indoor Air Levels published by the EPA
Herrick, R. F., Lefkowitz, D. J., & Weymouth, G. A. (2007). Soil Contamination from PCB-Containing Buildings. Environmental Health Perspectives , 115 (2), 173-175.
Look for future consulting blogs about environmental health and safety, and industrial hygiene topics including mercury, lead and heavy metals. Please contact Triumvirate’s consulting group for more information. We have Environmental Engineers and Consultants ready to answer your questions.
Posted on Wed, Sep 30, 2009 @ 08:44 AM
By Sean Reagan, Corporate Director of Higher Education
Long awaited guidance from EPA Headquarters on the issue of PCB-laden building caulking material provides us with a great deal to digest. Although the EPA states that the presence of PCBs should not be cause for alarm -effectively managing this complex issue is cause for alarm for many school administrators and facility managers. Here's a first pass on the highlights of this guidance:
1. EPA was careful to not use "must" or "shall" language and maintained "may" and "should" language in this guidance. Testing (caulk sampling or indoor air) is still not required however, indoor air testing in schools is strongly recommended to determine if their is an immediate exposure risk to children in schools.
2. EPA acknowledges the growing amounts of evidence of the presence of levels of PCBs in caulk used in older buildings (1950-1978) - generally not concerned YET about newer buildings (but this may still be a problem).
3. IMMEDIATE MITIGATION STEPS - The released guidance are steps building owners and school administrators should take to minimize potential exposure. Immediate steps include cleaning air ducts, improving ventilation, clean frequently-reduce dust, wash children's hands frequently, among a few other common sense steps.
4. INDOOR AIR TESTING - Beyond immediate steps, EPA recommends testing to determine if PCB levels in the air exceed EPA's suggested public health levels. If testing reveals PCB levels above these levels, schools should be especially vigilant in implementing and monitoring practices to minimize exposures. If a second test after immediate steps taken do not lower indoor levels - schools should (not required) take steps to remove peeling caulk. In short - it is believed that if you fail the second air test you will be remediating the PCB Caulk and contact building materials under the direction of the Regional PCB Coordinator.
5. PCB INDOOR AIR THRESHOLDS - EPA published Public Health Levels of PCBs in School Indoor Air (ng/m3) - indoor air concentrations below these levels are believed to keep total exposure below EPA reference dose (in other words - "safe").
6. ADDITIONAL RESEARCH - EPA states that they need more time to complete research on questions related to the magnitude of unresolved scientific questions such as the link between the concentrations of PCBs in caulk and PCBs in the air or dust. More to come on this......some schools may be recruited to participate in these studies to include methods to mitigate exposures to PCB caulk including encapsulation of the caulking as well as contact material (wood, brick, concrete).
7. SCHOOLS and CONTRACTORS INFO KIT - Guidance contains useful communication and information tools for school administrators, teachers students as well as contractor who may come in contact with caulking.
Posted on Fri, Sep 11, 2009 @ 03:20 PM
By Jason Atwood, Field Services Manager
What are PCBs?
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 cuasing 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!.
For more information about PCBs go to www.epa.gov/pcb, call EPA's Toxic Substances Control Act Hotline: 202-554-1404, or email me at jatwood@triumvirate.com.