PCBs….in building caulk

We’re all used to polychlorinated biphenyls (PCBs) in transformers.  But PCBs in building caulk is a rapidly emerging environmental problem.

Here’s some facts:

• PCB-containing caulk was widely used between 1950 and 1978 and is commonly found in buildings built or renovated during this period.
• The amount of PCBs in caulk can be up to 30%.
• PCBs were used as a plasticizer. They made the caulk more flexible.  In 1969 alone, 19 million pounds of PCBs were used as a plasticizer in various products.
• PCB-containing caulk was frequently used around windows and doors, at the interface of buildings and walkways, within expansion joints, and between masonry and concrete surfaces in commercial and multi-unit residential buildings.

Why are PCBs in caulk a problem?

Over time, the caulk degrades and is released into the surrounding environment.  Once released, it creates dust and debris that can contain PCBs.  On the exterior of buildings, the PCBs can accumulate in soil.  Both the PCB-containing dust and soil can be touched, ingested or inhaled by building occupants.

While PCBs are relatively non-volatile, PCB-containing caulk can off-gas PCBs into indoor air at low rates over time where people can inhale them. So even where PCB-containing caulk is in good condition, PCBs can be released and people can be exposed.

PCBs in caulk can represent a significant liability if you own or are buying a building that was built or renovated between 1950 and 1978.

• If you own a building, your current occupants may be exposed to PCBs.  Furthermore, it’s increasingly likely that, when you sell your building, buyers will be looking for data showing the building is PCB-free.
• If you’re in the market to buy a building, you may want to know whether PCB-containing caulk is present to avoid buying someone else’s problem.

In both circumstances, a site assessment for PCB-containing building materials can help you manage risk.

If you want more info, check out this fact sheet on PCBs in caulk from the United States Environmental Protection Agency.