Pollutant Guides 3 min read

PCB in Sealants: The Toxin in the Joint

PCB in building joints: where it hides, why it is dangerous, and how to get it tested. Typical in buildings from the 1960s–1980s.

PCB — polychlorinated biphenyls — are a group of 209 synthetic chlorinated hydrocarbons. Thermally stable, chemically inert, elastic. These very properties made them the ideal additive in joint sealants, gaskets, and coatings. And these very properties make them a problem today: PCB are practically non-degradable in the environment.

In Austria, PCB-containing joint sealants were extensively used between approximately 1955 and 1978 — primarily in prefabricated concrete buildings, office buildings, and schools. PCB has been banned in Austria since 1988. But the joints are still there.

Where PCB Is Found in Buildings

In the buildings we inspect — primarily concrete structures from the 1960s and 70s — we find PCB almost always at the same locations:

  • Building joints: Elastic sealants between prefabricated concrete elements, on facades, between floor slabs and exterior walls. This is the most common source.
  • Window joints: Sealants around window frames, especially with aluminium windows from the 1960s–1970s.
  • Expansion joints: In floors, car parks, industrial buildings.
  • Coatings and surface treatments: Less common, but possible — PCB was also used in anti-corrosion coatings and certain ceiling panels.

The joint sealants are typically grey, beige, or black, elastic to brittle, and often cracked. Their age is evident.

Why PCB Is a Problem

PCB continuously off-gasses from the joint sealant into the indoor air — over decades. At the same time it accumulates in household dust. In the body, PCB are fat-soluble: they deposit in fatty tissue and break down only extremely slowly. The biological half-life is 2 to 15 years depending on the congener.

IARC classifies certain PCB congeners as Group 1 carcinogens — definitively carcinogenic. Further health effects: liver damage, immunosuppression, disruption of the hormonal system (endocrine disruption). Children and pregnant women are especially at risk.

In Austria, a guideline value of 300 ng/m³ PCB total in indoor air applies as the threshold for action. At values above 3,000 ng/m³, immediate measures are required.

PCB often occurs together with other pollutants. In buildings from the 1960s–1980s, we frequently find asbestos alongside PCB (→ Recognizing Asbestos) and old MMF (→ MMF: When Old Insulation Becomes a Problem).

How We Detect PCB

We take a material sample of the suspected joint sealant — a small piece of a few centimetres. The sample goes to an accredited laboratory, where it is analysed by GC-MS (gas chromatography-mass spectrometry) for the relevant PCB congeners.

If indoor air exposure is suspected — for instance when joints lie open over large areas or when complaints exist — we can also arrange an indoor air measurement.

PCB analysis is quoted after the initial consultation — scope depends on sample type, detection limits and number of samples. Result in 5–7 business days.

→ More about PCB analysis

What You Should Do

PCB joint sealant found, intact, and no indoor air exposure: Document and have it professionally removed during the next renovation.

Joints open, cracked, or extensively exposed indoors: Indoor air measurement recommended. At values above 300 ng/m³: initiate measures — either sealing the joints (reduces off-gassing by 70–90%) or professional removal.

Renovation planned: PCB-containing joint sealants are hazardous waste. Removal must be carried out by a specialist firm — with protective measures similar to those for asbestos.

When You Should Get in Touch

You are renovating an office building or school from the 1960s or 70s? You see cracked, old joint sealants on prefabricated concrete elements? You are planning window replacement in a building of this era?

A pollutant check before a home purchase (→ Pollutant check home purchase) routinely covers PCB.

15-minute initial consultation, free of charge.

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