Ninety Vermont School Districts, One Manufacturer: Reconstructing Decades-Old PCB Exposure in Classrooms
By Paul E. Rosenfeld, M.S., Ph.D., Principal Environmental Chemist, RoseyFields LLC, Santa Monica, California
PCBs built into the walls before anyone knew better
Between the 1950s and their 1979 federal ban, PCBs were routinely used in caulking, window glazing, sealants, and light-ballast capacitors in commercial construction, including hundreds of school buildings still in use today. Dr. Paul E. Rosenfeld, M.S., Ph.D. of RoseyFields LLC has addressed the resulting indoor-air and dust exposure reconstruction in Vermont PCB-in-schools litigation against Monsanto and its corporate successors (Crawford, 2025).
A litigation wave spanning nearly the entire state
Vermont became the first state to require systematic PCB testing of older school buildings, a program that identified widespread contamination and prompted nearly 100 Vermont school districts, along with the state attorney general and Burlington’s school district specifically, to sue Monsanto, seeking recovery of testing, remediation, and in some cases full building-replacement costs.
Why Burlington High School became the most extreme example
Burlington High School was closed entirely due to elevated PCB levels, with students relocated to a converted retail space while the original campus was ultimately demolished and replaced at a cost exceeding $165 million, illustrating the potential financial scale of PCB-in-schools exposure claims once remediation costs are fully quantified.
Indoor air and dust as the operative exposure pathways
Unlike outdoor air dispersion cases, PCB-in-schools exposure occurs primarily through indoor air off-gassing from PCB-containing caulk and sealants and through settled dust ingestion, requiring an exposure assessment built around indoor air sampling, building-material testing, and dust-loading measurements rather than atmospheric dispersion modeling.
Quantitative exposure methodology recognized by a federal court
In related Vermont federal litigation against Monsanto, the court specifically credited the use of EPA default exposure assumptions, Average Daily Dose calculations, hazard quotients, and statistically supported upper confidence limits, along with integration of air, dust, and exposure-duration variables, as a scientifically reliable methodology for exactly this kind of indoor building-material exposure scenario (Austin, 2025).
The regulatory and toxicological basis for PCB concern
EPA’s PCB regulations under the Toxic Substances Control Act (40 CFR Part 761) reflect the agency’s determination that PCB-containing building materials require remediation, and IARC classifies PCBs as carcinogenic to humans (Group 1), a classification grounded in extensive occupational and environmental epidemiology (IARC, Vol 107).
Building-material sampling as a distinct evidentiary category
Because PCB concentrations vary enormously between different caulk formulations, sealants, and light-ballast types even within the same building, a defensible exposure reconstruction requires material-specific sampling and testing rather than assuming a single building-wide contamination level, an approach consistent with the material-specific dioxin and furan sampling methodology Dr. Rosenfeld has applied in other legacy contamination matters (Gonzalez et al., 2010).
Age-specific exposure considerations for a school population
Because schools house children whose hand-to-mouth behavior, breathing rates relative to body weight, and developmental sensitivity differ substantially from an adult occupational population, PCB-in-schools exposure assessment applies EPA’s age-specific default exposure factors rather than adult occupational assumptions, a distinction central to the dose calculations credited in the Austin litigation.
Why manufacturer liability, not just building owner liability, is the central legal question
A recurring feature of this litigation is Monsanto’s argument that it never manufactured, used, or disposed of PCBs directly in the affected state and that the PCB-containing products were produced by third-party companies using Monsanto-supplied PCB chemicals, a corporate-responsibility dispute distinct from, but dependent upon, the underlying exposure and contamination evidence.
Why PCB-in-schools litigation is likely to keep expanding
With Vermont’s testing program serving as a model other states have begun to consider, and with hundreds of schools nationally constructed during the same mid-twentieth-century period using similar PCB-containing materials, the exposure reconstruction methodology developed in Vermont litigation is likely to see application in other states’ school PCB matters in the coming years. Further reading on Dr. Rosenfeld’s PCB indoor air and dust exposure assessment work is posted at RoseyFields.com.
References
1. Crawford C, et al. v Monsanto Company, Solutia Inc., and Pharmacia LLC. Docket No. 2:23-cv-752, US District Court for the District of Vermont.
2. Austin, et al. v Monsanto Company, Solutia Inc., and Pharmacia LLC. Case No. 2:23-cv-272, US District Court for the District of Vermont.
3. Burlington School District v Monsanto Company, Solutia Inc., and Pharmacia LLC. US District Court for the District of Vermont, filed 2022.
4. State of Vermont v Monsanto Company, Solutia Inc., and Pharmacia LLC. US District Court for the District of Vermont.
5. IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Polychlorinated Biphenyls and Polybrominated Biphenyls. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol 107. Lyon, France: International Agency for Research on Cancer; 2016.
6. US Environmental Protection Agency. Polychlorinated Biphenyls (PCBs) Manufacturing, Processing, Distribution in Commerce, and Use Prohibitions. 40 CFR Part 761.
7. Vermont Agency of Education; Vermont Department of Environmental Conservation. PCBs in Schools Testing Program. Montpelier, VT: State of Vermont; 2021.
8. Gonzalez J, Feng L, Sutherland A, Waller C, Sok H, Hesse R, Rosenfeld P. PCBs and dioxins/furans in attic dust collected near former PCB production and secondary copper facilities in Sauget, IL. Procedia Environ Sci. 2010:113-125.
9. US Environmental Protection Agency. Exposure Factors Handbook. Washington, DC: US EPA Office of Research and Development.
10. Agency for Toxic Substances and Disease Registry. Toxicological Profile for Polychlorinated Biphenyls (PCBs). Atlanta, GA: US Department of Health and Human Services; 2000.
11. US Environmental Protection Agency. PCBs in Building Materials, Including Caulk. Washington, DC: US EPA.
12. Rosenfeld PE. RoseyFields LLC: PCB Indoor Air and Dust Exposure Assessment for Educational and Institutional Buildings. Santa Monica, CA: RoseyFields LLC; 2026.
13. US Environmental Protection Agency. Revisions to the Guideline on Air Quality Models. 40 CFR Part 51, Appendix W. Fed Regist. 2017;82(10):5182-5235.
14. US Environmental Protection Agency. Toxic Substances Control Act (TSCA) Overview. Washington, DC: US EPA.