Until they were banned by the Federal Government in 1978, Polychlorinated Biphenyls or PCBs, were used extensively as sealants in Brutalist structures across the United States. As a result, these hazardous chemical compounds still reside in concrete buildings and present a danger to those looking to clean or renovate Brutalist structures. This talk explains the problems the University of Massachusetts Amherst has faced in dealing with PCBs over the last couple of decades and recommends some best practices for owners, designers, builders working on midcentury buildings which are suspected to contain these dangerous chemicals.