Indoor environment factor · measured in ng/m³
Polychlorinated biphenyls (PCBs)
Also: PCB, PCBs, polychlorinated biphenyl
A family of chlorinated industrial compounds banned decades ago and still present in buildings that were constructed while they were in use. They were put into sealants, paints and light fittings, and they leave those materials slowly into air and dust.
What it is
This is the clearest case in the vocabulary of a source that no occupant chose and no occupant can see. Polychlorinated biphenyls were used as plasticisers and dielectric fluids from the 1950s until they were banned, and buildings of that period contain them in elastic joint sealants, in some floor and wall coatings, and in the capacitors of fluorescent light fittings.
They are semi-volatile, so they leave the original material into the air, deposit onto every other surface in the room, and are taken up by porous materials that then become secondary sources of their own. This is why concentrations in an affected building stay high long after the primary source is removed, and why remediation that takes out the sealant alone often disappoints.
Schools built in the period are where most of the measurements have been made, and where ventilation has been the usual interim measure.
What the studies report
| Linked to | Effect | Population | Study design | Source | Checked |
|---|---|---|---|---|---|
| Ventilation | one building; the study also reports encapsulation of the accessible caulk at 22 %, from 282 to 220 ng/m3, which was only marginally significant | — · school | intervention study in a school building with polychlorinated biphenyls in the caulk: indoor air concentrations measured before and after improved ventilation, encapsulation of accessible caulk, encapsulation behind convectors and construction of false walls, normalised and compared with the Wilcoxon rank sum test | F-1448 Mitigation of building-related polychlorinated biphenyls in … (2012) | machine |
Each row is one Finding — a sentence as printed in one study, recorded with its page in the Coridum Knowledge Base. Follow the Finding number for the exact wording and the citation. Checked says who verified the row: machine means every automatic check passed and the surrounding text was read; person means someone read the sentence in the document. Rows are re-checked by a person over time. The studies are curated in the Coridum Knowledge Base; the reading of them together is a Claim, shown separately.
Cite this page
Coridum Research. Polychlorinated biphenyls (PCBs). Coridum Knowledge G-0201, 16 September 2026. https://coridum.com/k/G-0201/