In response to evidence of adverse health and environmental impacts, the Environmental Protection Agency (EPA) banned the manufacture of polychlorinated biphenyls (PCBs) in 1979 and imposed controls on the majority of PCBs in use at that time.
PCBs are mixtures of synthetic organic chemicals valued for their stability, low flammability, and high thermal conductivity. Because of these properties, PCBs were extensively used as a non-flammable replacement for mineral oil to cool and insulate transformers, fluorescent light ballasts, and other electrical devices. The use and disposal of this equipment has been strictly regulated under the Toxic Substances Control Act (TSCA), found in the federal code of regulations at 40 CFR 761.50.
The EPA has determined that PCBs are a probable human carcinogen and may cause a variety of other non-cancer health effects. PCBs easily penetrate the skin; are highly soluble in organic solvents, oils and fats; and can bioaccumulate up the food chain. Toxic effects in humans vary among different PCB compounds and may include skin rashes; liver, gall bladder and gastrointestinal cancer; increased rates of melanomas; and lowered immune response.
PCBs in Building Materials
From the 1920s until they were banned in 1979, the United States produced an estimated 1.5 billion pounds of PCBs. In addition to transformers and electrical components, lesser known uses of PCBs include such manufacturing and building components as: plasticizers in paint, stabilizers for flexible electrical cable coatings, pesticide extenders, sealants, caulking, window glazing, adhesives, certain wood floor finishes, and waterproofing compounds. PCBs were used in concentrations ranging from 1% to 20% in these products and were widely used in buildings and schools constructed or renovated between 1950 and 1978.
Fluorescent light ballasts manufactured before 1979 may contain PCBs and are susceptible to leaking or rupturing. Even intact light ballasts under normal use may emit small amounts of PCBs into the air. Removal and replacement of such light ballasts is an EPA-recommended best management practice (BMP).
Caulking and elastic sealant material around windows, door frames, masonry joints and window glazing may release PCBs in connection with building renovation and repair. They may also be released from these materials by off-gassing – impacting adjoining porous media and leaching into soil from precipitation.
PCBs added to specialty paints and coatings were not typically used for interior and exterior decorative applications, but have been found in schools and buildings. If PCBs are present or suspected, building owners and school administrators can take steps to reduce potential exposure to students and building occupants.
Removal and Disposal of PCBs
The EPA recommends that an experienced contractor or properly-trained building maintenance staff perform the removal, cleanup and disposal of PCB light ballasts and other PCB-containing building materials. Steps to ensure safe and effective removal include characterization of potential PCB-containing building materials, sample collection and interpretation, risk assessment, development of an abatement strategy, project management and documentation.
Prior to removal, PCB testing is recommended for caulking, window glazing, sealants and other suspect building materials to determine what protections are needed. To avoid contamination of surrounding surfaces during removal/replacement of window glazing and caulking, properly-trained workers should follow safe work practices to minimize dust and contain contaminated waste. Physical barriers and the use of negative pressurization may be necessary to isolate work areas and prevent PCB exposure in adjacent spaces.
There is currently no EPA method that is specific to sampling for PCBs in dust and residue on interior building surfaces. A commonly used method involves surface wipe sampling of a 100 square-centimeter area with a solvent-wetted gauze material, and analysis of the gauze for PCBs. Several laboratory methods have been developed for analysis of non-liquid materials such as caulk, glazing and paint.
When testing confirms the presence of PCBs at regulated levels, they must be disposed in accordance with TSCA regulations. Disposal requirements for PCB waste described in 40 CFR 761.60 are complex and stipulate different disposal options depending on PCB concentration, type of PCB waste, and how and when the PCB waste was generated. Incineration or burning in a high efficiency boiler is required for certain PCB liquids. If certain requirements are met, fluorescent light ballasts, capacitors and other bulk PCB waste may be disposed in a chemical waste landfill or as municipal solid waste.
Although the EPA may pursue enforcement actions for violation of TSCA regulations, they recognize that enforcement may not be the most effective approach to reduce health risks. EPA’s focus is to provide guidance and assistance to school districts and building owners, and encourage the implementation of BMPs and other actions to reduce exposure.
HETI…Assistance and Advice with PCB Issues
Due to the known adverse impacts of PCBs and because it can take decades for PCBs to degrade, identification, management and proper disposal of PCB-containing building materials are crucial in reducing exposure and mitigating risk to building occupants.
HETI can help building owners/managers and school administrators address PCB issues – including its characterization, removal and disposal.
Whether it’s PCBs, asbestos, lead-based paint, mold, indoor air quality or other environmental issues related to building management, HETI is here to advise and assist.