Caulk is a flexible material most commonly used to seal cracks in some building materials and gaps where building materials meet, such as those around door and window frames. PCBs, an oily substance, were added to caulk and industrial paints to increase flexibility in those materials. Aging caulk tends to harden, becoming friable or brittle and crumbling into particles which can be found on windowsills, accumulate on floors, or find their way into ventilation systems. 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 1978.
Since 2008, high levels of PCBs have been found in caulk in over 30 Brooklyn, NY, schools that were being renovated. Some of the NY schools reportedly contained levels of PCBs more than 6,000 times the concentration deemed by the EPA to present an “unreasonable risk of harm” to students. Studies completed since the 1970s have found that PCBs are not only carcinogens, but can impair several body systems, including the reproductive, immune, endocrine and central nervous systems.
Administrators of potentially affected buildings who fail to take appropriate action may face legal liability. For example, the situation with the NY schools has prompted lawsuits against the school systems involved for failing to take reasonable precautions to protect children from the danger.
In September, 2009, the EPA recommended testing for affected buildings and announced new guidance for school administrators and building managers, including information to assist with management of the hazard and minimizing possible exposure. Commercial production of PCBs ceased in 1978, and the EPA guidelines urge, but do not yet require, all schools and other buildings that were constructed between 1950 and 1978 to obtain testing.
However, while the manufacture of caulk containing PCBs did not become mainstream practice until the 1950s and was banned in 1978, it is possible that caulk containing PCBs made its way into construction projects for a period of years before and after those dates. Some organizations urge testing of buildings constructed or renovated as early as the 1930s and as late as 1980.
In the meantime, the agency has urged all schools constructed in the at-risk era to take provisional steps as precautionary measures until it is possible to ascertain from testing whether the building is contaminated with PCBs. Those steps include:
- Improve ventilation, including opening windows and using or installing fans where possible.
- Clean frequently to reduce dust and residue inside buildings.
- Use a wet or damp cloth or mop to clean surfaces.
- Use vacuums with high-efficiency particulate air (HEPA) filters.
- Do not sweep with dry brooms; minimize the use of dusters.
- Wash children's hands with soap and water often, particularly before eating.
- Wash children's toys often.
- Wash hands with soap and water after cleaning, and before eating or drinking.
The EPA is also offering assistance with identification of problems and any necessary testing and removal plans. A Fact Sheet and a Q&A are available on the EPA website. The agency plans to undertake additional research into seemingly unexplained additional mechanisms by which PCBs contained in caulk have been leaching or seeping into the air and soil in and around contaminated school and other buildings.
Schools and other buildings that might be affected should take steps to obtain testing, and should immediately implement the EPA’s recommendations for provisional safety measures, as outlined above. If a building is found to be contaminated with potentially dangerous levels of PCBs in caulk, the caulk must be removed using approved abatement and removal procedures, designed to minimize human exposure to the substance or migration of the substance to ventilation, water supplies, or soil during removal.