Polychlorinated Biphynels (PCBs) are man-made oily liquids or solids, colourless to yellow, with no smell or taste. They have been commercially manufactured since the 1930's, and used in hundreds of applications due to their non-flammability, chemical stability, high boiling point and electrical insulating properties.
PCBs have been used within electrical, heat transfer and hydraulic equipment; as plasticisers in paints, plastics and rubber products; in pigments, dyes and carbonless copy papers; and in many other applications.
PCBs are non-soluble in water and build up in fatty tissues, which makes it difficult for animals and humans to eliminate them from the body. PCBs are also known to accumulate in the above ground parts of plants, including stems, leaves and fruit.
The United States Environmental Protection Agency (US EPA) has found clear evidence that PCBs have significant toxic effects, including on the immune, reproductive, nervous and endocrine systems. Studies have also indicated PCBs are carcinogenic.
Photo: PCB containing capacitors to old electrical equipment
Most PCBs in built environments are within older electrical capacitors, where they act as an insulator and coolant.
Larger capacitors or transformers, in very high voltage equipment, may contain several litres of PCB liquid.
Smaller capacitors, such as in older fluorescent light fittings, can be found in many sites and. although minor in each case, may add up to a significant volume for a large site.
Any capacitors manufactured before 1980 should be considered potentially suspect, with metal casings usually indicating PCBs present.
Suspect capacitors can be compared to the lists of PCB containing types given in the ANZECC information booklet;
BENSS provides PCB Identification & Risk Assessment, Management Plans for PCB containing equipment still in use, and advice for safe removal and disposal.