Polychlorinated Biphenyls (PCBs) Persistent Organic Pollutants (POPs) have been identified by the international community for immediate international action by means of the Stockholm Convention. The pesticide DDT, highly toxic Dioxins and Furans (unintentionally formed by-products as a result of incomplete combustion or chemical reactions) as well as PCBs count among the POPs.
PCBs have serious health and environmental effects, which can include carcinogenicity, reproductive impairment, immune system changes, and effects on wildlife causing a loss of biological diversity. PCBs bio-accumulate in the fatty tissue of humans and other living organisms. The chemical is transported over long distances to regions where it has never been used or produced before. This process of evaporation, movement with the air streams, condensation and deposition on the ground is known as the “grasshopper effect”.
PCB production started in 1929. PCBs were manufactured by a number of companies in many industrialized countries, and maximum production was reached in the late 1960s. After 1983 production was stopped in most countries, except for some Eastern European countries and Russia, where manufacture ceased between 1987 and 1993.
PCBs were mostly used in closed applications for example as cooling and isolating agents in transformers and capacitors, in heat transfer systems and hydraulic systems, in particular in mining equipment. PCBs mixtures were, however, also widely used in open and partially open applications, for example in caulks/sealants, paints, anti-corrosion coatings, surface coatings, cables and cable sheaths, small capacitors, etc.
From the technical point of view, the characteristics of PCBs were quite advantageous, thus they found a wide range of applications as mentioned above.
The Stockholm Convention on Persistent Organic Pollutants (POPs) counts PCBs among the substances targeted for worldwide elimination. The existing PCBs and all equipment contaminated with PCBs have to be eliminated in an environmentally sound manner without producing hazards for humans or the environment by 2028. PCB treatment or disposal technology must comply with the highest safety and environmental standards and must be capable of reducing the PCB contamination level of those pieces of equipment suitable for re-classification below the legally permitted level of 50 ppm as well as assure that the PCB level remains below that limit.
Other global and regional conventions regulate the management of dangerous chemicals and hazardous wastes addressing PCB such as the Basel Convention, as well as the Rotterdam Convention.