Paints and varnishes

Until 1972, PCBs were used as plasticisers and flame retardants in paints and varnishes.

Products containing PCBs were used to coat a very wide variety of surfaces. In addition to concrete paints and varnishes for metals, emulsion priming and top coats for use on concrete or plasterwork also contained PCBs. The PCB levels in old paints nowadays normally lie in the region of a few hundred mg/kg up to a few per cent. Depending on the PCB level in the paint, the area painted, the temperature and the degree of ventilation, paints containing PCBs inside buildings may cause PCB pollution in the ambient air.

In the 1970s in Germany, certain acoustic ceiling tiles (of the "Wilhelmi" type) were treated by the manufacturer with an open porous paint that contained a highly-chlorinated PCB compound (Clophen A60) in concentrations of up to 20 %. In rooms with these ceiling tiles in Germany greatly increased PCB concentrations have been measured in the ambient air. In a few cases, acoustic ceiling tiles containing PCBs were also used in Switzerland.

Old paint finishes and acoustic ceiling tiles suspected of containing PCBs in buildings should be checked in advance of any structural alterations to determine the PCB levels. Painted surfaces containing PCBs must be removed by specialists using the appropriate procedure and safety measures, so that any toxic effects on workers and the environment due to dust, aerosols or waste containing PCBs is avoided.

Immediate renovation work is required where the annual average value in the ambient air amounts to more than 6 micrograms per m³. This value applies to buildings occupied by people during working hours, such as schools and office buildings. For buildings that are constantly occupied, such as private housing and residential homes, a value of 2 micrograms per m³ of ambient air applies.