This document discusses PCBs (polychlorinated biphenyls) in building materials, which can be a health issue in schools. PCBs were commonly used in caulking and other building materials before 1977. Exposure to PCBs is linked to cancer and effects on the immune, reproductive and nervous systems. The document outlines steps for identifying PCB-containing materials, testing, exposure assessment, and remediation strategies like removal or barriers. Case studies show widespread PCB contamination found in caulking at schools, resulting in delays and high costs to address the problem. Proper testing and remediation is needed to reduce PCB exposure, especially in schools.