PCB is a synthetic chemical used in a wide variety of construction materials. It is thermally and chemically stable, flame-resistant and electrically non-conductive. PCB was mainly used as a plasticiser, in expansion-joint compounds, as a coolant and in hydraulic fluids. Pure PCB is practically odourless. The abbreviation stands for polychlorinated biphenyls, a group of chlorinated chemical compounds.

Uses of PCB PCB was used in lubricants and hydraulic fluids, as a plasticiser in paints and plastics — sometimes accounting for up to 50 percent of their weight — and in joint sealants, including permanently elastic expansion joints in concrete structures and joints around doors, windows and sanitary installations. It was also used in insulating materials. PCB-containing insulating oils were formerly used in capacitors, which can still be found in older technical equipment. The markings MP, MKP and MPK on capacitors indicate that they are PCB-free.

PCB was also used as a flame retardant in paints and varnishes, in white coatings for walls and acoustic ceiling panels because of its acoustic properties, and in flooring adhesives.

Remediation procedure 1. Identify the PCB sources. 2. Determine and assess indoor air contamination. 3. Select the remediation method and prepare a work and safety plan under BGR 128 / TRGS 524. 4. Set up the site and have a competent contractor remediate contaminated components, including primary and secondary sources. 5. Clean surfaces. 6. Coat critical surfaces that act as secondary sources. 7. Carry out verification measurements.

Effects on the environment and health

PCB can enter the body through the digestive tract, the skin or inhalation of vapours. It spreads rapidly and accumulates in fatty tissue. PCB is a highly hazardous environmental pollutant. Because it is fat-soluble and does not readily break down in the environment, it spreads globally and accumulates in the food chain. PCB released into the environment persists in the food cycle. It can damage the liver, spleen and kidneys and is carcinogenic.

Hazard identification and assessment Outdoor air around buildings with PCB sources can contain concentrations of up to 10 ng/m³. Indoor concentrations can reach 1,000 ng/m³ and, in individual cases, 10,000 ng/m³. Investigations showed that PCB-containing materials used indoors before the 1972 prohibition can still contribute to indoor air contamination.

Many questions remain about the long-term effects of low-level PCB exposure on humans. Improper remediation is strongly discouraged because of the risk of uncontrolled release. Indoor contamination can be substantially higher after improper removal than before remediation.