Yep. Polychlorobiphenyls (PCB) are found in caulking. Typically buildings before 1979 have this caulk. (EPA Facts about PCB in Caulk) The only way to know is to test. BUT, wait!


  • Assume you have it and renovate with caution. Or,
  • Have the air tested for PCBs in the air.

Do not have a bulk sample taken. You should ask for an exposure assessment to be performed (air monitoring) by a qualified industrial hygienist. The reason is two-fold.

  1. The potential for the hazard is airborne. In most instances, people aren’t getting exposure from any other method.
  2. By measuring the air, you account for any other sources of PCBs (paint, ballasts, oils, ceiling tiles).

Most of this caulk is found in outdoor uses (high grade) in older buildings up to around 1980-ish. If an airborne exposure assessment finds levels below the acceptable rules & recommendations (depends on age & location), you may continue with your project. Of course, you would take appropriate precautions, like these recommendations from the EPA. They also have a very nice flow chart. Just like a choose-your-adventure book, make sure you don’t fall into the “Abatement” box!

EPA PCB Caulk flow chart