PCBs in Schools Research
Polychlorinated biphenyls (PCBs) are a class of organic chemicals that have been used in a variety of commercial products. PCBs were used in caulk, electronics, fluorescent light ballasts, and other building materials between about the 1950s and 1979. Buildings built or renovated during that time may contain PCBs in caulking and other materials.
In 1976, Congress banned the manufacture and use of PCBs because of concern about their health and environmental effects and they were phased out except for certain limited uses in 1979. Health concerns related to PCB exposure include, but are not limited to, cancer, reproductive effects and neurological effects.
In response to concerns raised by the public about PCBs in schools, EPA scientists have been identifying and evaluating potential sources of PCBs in schools to better understand exposures to children, teachers, and other school workers. EPA is also investigating methods to reduce or eliminate PCB emissions in a school setting.
- Caulk put in place between 1950 and 1979 may contain as much as 40% PCBs and can emit PCBs into the surrounding air. PCBs
from caulk may also contaminate adjacent materials such as masonry or wood.
- Fluorescent lighting fixtures that still contain their original PCB-containing light ballasts have exceeded their designed
lifespan, and the chance for rupture and emitting PCBs is significant. Sudden rupture of PCB-containing light ballasts may result
in exposure to the occupants and may also result in the addition of significant clean-up costs.
- Some building materials (e.g., paint and masonry walls) and indoor dust can absorb PCB emissions and become potential secondary
sources for PCBs. When the primary PCB-emitting sources are removed, the secondary sources often emit PCBs.
- Encapsulation is a containment method that uses a coating material to separate PCB sources from the surrounding environment to reduce surface and air concentrations of PCBs. Encapsulation is only effective at reducing air concentrations to desirable levels when PCB content in the source is low. Selecting high-performance coating materials is key to effective encapsulation. Multiple layers of coatings enhance the performance of the encapsulation.