What are PCBs and why are they found in buildings?

Polychlorinated biphenyls (PCBs) are a group of 209 synthetic organochlorine compounds that were produced industrially from the 1930s for their excellent chemical and thermal stability, electrical resistance and non-flammability. These properties made them attractive for many industrial applications and, in the construction sector, for specific building products.

In construction, PCBs were primarily incorporated into two types of products between approximately 1955 and 1975:

Sealing joints and expansion mastics: PCBs were used as plasticisers in the joint mastics between prefabricated concrete elements. These joints are present in facades, floors, car parks, civil engineering structures and prefabricated frame buildings typical of mass construction in the 1960s–1970s.
Anti-corrosion and floor paints: certain industrial paints based on chlorinated resins contained PCBs as plasticisers. These are found in industrial buildings, covered car parks, factory halls and certain public buildings from that period.
Electrical capacitors and transformers: PCBs were used as a dielectric fluid in capacitors and certain transformers installed in technical rooms. Although these are equipment rather than building materials, their presence can lead to contamination of surrounding spaces in the event of a leak.
Waterproofing and caulking products: certain products used for waterproofing cellars, roofs or tanks could contain PCBs.

Period of use and prohibition in Switzerland

PCBs were used in buildings primarily between 1955 and 1975. Following the gradual recognition of their toxicity and environmental persistence, their production and use were progressively restricted. In Switzerland, PCBs were banned in new applications from 1986.

This prohibition date means that buildings constructed or renovated between 1955 and 1986 may contain PCB-based products. In practice, buildings from the 1960–1975 period are the most affected, as this decade saw the greatest prevalence of prefabricated concrete construction and PCB-based jointing products.

Ageing PCB joints progressively degrade: they retract, crack and become brittle. The substance then migrates to adjacent concrete surfaces and into ambient dust, contaminating areas near the joints. In buildings with joints in poor condition, significant PCB concentrations may be measured in indoor air and in surface dust.

The buildings most affected

The presence of PCBs in buildings is strongly correlated with the construction period and type:

Prefabricated concrete residential buildings: prefabricated element construction was widespread for large residential developments of the 1960s–1970s (social housing, rental apartment buildings, housing cooperatives). Joints between facade panels and between floor elements are the priority locations to check.
Administrative and school buildings: public constructions from the 1960–1975 period (town halls, schools, gymnasiums, administrative buildings) frequently used the same prefabricated construction techniques.
Covered and semi-underground car parks: prefabricated concrete car park structures often have PCB expansion joints across large surface areas.
Industrial buildings: industrial halls, warehouses and production buildings constructed or renovated between 1955 and 1975 may contain anti-corrosion or floor paints with PCBs.
Hospital and institutional buildings: the mass construction of hospitals and care establishments in the 1960s–1970s often used joint materials containing PCBs.

Health and environmental risks of PCBs

PCBs are recognised as priority hazardous substances due to three combined characteristics:

Persistence: PCBs degrade very slowly in the environment. Once released, they persist in soils, sediments and living organisms for decades.
Bioaccumulation: PCBs accumulate in the fat of living organisms and concentrate through the food chain. Organisms at the top of the food chain — including humans — show the highest concentrations.
Toxicity: PCBs are toxic at many levels. They disrupt the hormonal system (endocrine disruptors), affect the immune system, have neurotoxic effects, and are classified as probable human carcinogens by the World Health Organization. Some PCB congeners are classified as proven carcinogens.

In terms of risks in buildings, the exposure pathways are inhalation of indoor air contaminated by degraded joints, skin contact or ingestion of contaminated dust during works on PCB-containing materials.

The Swiss regulatory framework

The ORRChim (Ordinance on the Reduction of Risks from Chemical Products, RS 814.81) prohibits the use and placing on the market of PCBs in Switzerland. It also defines the thresholds above which materials containing PCBs must be treated as special waste.
The Ordinance on the Movement of Waste (OMoD) classifies waste containing PCBs above regulatory thresholds (generally 50 mg/kg) as special waste. Their transport and disposal are subject to strict procedures, with the issuance of tracking documents.
The Ordinance on Construction Work (OTConst) requires verification of hazardous substances before any construction site. PCBs fall into this category: before any construction site likely to disturb joints, paints or other PCB-containing materials in a building from the relevant period, prior verification is required.
The Stockholm Convention classifies PCBs among the persistent organic pollutants (POPs) to be eliminated. Switzerland, a signatory to this convention, has committed to progressively eliminating PCBs from its territory.

Analytical methods for PCBs

The presence of PCBs in a material cannot be determined visually. Laboratory analysis is indispensable.

Material sampling: samples of joints, paints, surface dust or concrete adjacent to joints are taken according to standardised protocols. The quantities sampled are small but sufficient for analysis.

Chemical laboratory analysis: samples are analysed by gas chromatography coupled with mass spectrometry (GC-MS) or by electron capture detector (GC-ECD). These methods allow the different PCB congeners present to be identified and quantified, with a sensitivity allowing very low concentrations to be detected.

Indoor air measurements: in buildings showing significant signs of PCB joint degradation, measurements of PCB concentration in ambient air can be carried out to assess the actual exposure of occupants.

How a PCB diagnosis works

Preliminary inspection: the specialist inspects the building to identify zones with expansion joints, paints or other materials likely to contain PCBs. They assess the state of degradation of visible joints and identify priority locations for sampling.
Targeted sampling: samples are taken from suspect materials identified during the inspection. The number of samples depends on the surface area and the diversity of materials present.
Laboratory analyses: samples are transmitted to a SAS-accredited laboratory for analysis by GC-MS or GC-ECD.
Report and recommendations: the report specifies the positive materials with their concentrations, location and condition. It formulates recommendations on the measures to be taken according to the contamination levels detected (emergency measures, removal programme, protective measures for works, monitoring).
Management plan: for buildings with significant contamination, a management plan is established to define the sequence and methods of decontamination.

The decontamination obligation

When PCBs are detected above regulatory thresholds in a building, decontamination is required. It can take several forms:

Joint replacement: contaminated joints must be removed by a specialised company with adequate protective equipment and replaced with PCB-free products. The resulting waste is disposed of as special waste.
Treatment of contaminated surfaces: the concrete adjacent to joints may have absorbed PCBs through migration. Depending on the concentrations measured, abrasion or surface treatment may be necessary.
Ventilation and air remediation: in buildings with indoor air contamination, reinforced ventilation measures may be recommended during and after decontamination.

PCB diagnosis in Geneva and the canton of Vaud

Buildings constructed between 1955 and 1975 in the cantons of Geneva and Vaud are the most affected by the presence of PCBs, particularly rental apartment buildings, school buildings and industrial constructions. The large housing estates of the 1960s–70s in Meyrin, Vernier, Onex and Renens present a high risk of PCBs in expansion joints and glazing mastics.

Our diagnosticians operate throughout both cantons for PCB investigations, often carried out in conjunction with an asbestos diagnosis.

Multi-pollutant approach: PCBs, asbestos, PAHs and HBCD

In buildings from the 1955–1975 period, several pollutants may coexist: asbestos in technical installations and roofs, PCBs in joints and paints, PAHs in bituminous coatings. A multi-pollutant diagnostic approach, carried out in a single mission, allows all hazardous substances to be identified while optimising inspection time and analysis costs.

This comprehensive approach is particularly relevant for heavy renovation or demolition projects, where all materials will be affected. For more information on other building pollutants, visit the PAH diagnosis and lead diagnosis pages.

To request a PCB or multi-pollutant diagnostic quote in Western Switzerland, visit the asbestos diagnosis quote page.

PCB Diagnosis in Switzerland