RECETOX, Masaryk University, Brno, CR
holoubek@recetox.muni.cz; http://recetox.muni.cz
Ivan Holoubek
CHEMIE ŽIVOTNÍHO PROSTŘEDÍ IV
Vybrané typy environmentálních polutantů
(08/05)
Polychlorované bifenyly (PCBs)
Inventura zařízení
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PCB Applications
 CLOSED SYSTEMS
 OPEN SYSTEMS
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Closed Applications
 A closed PCB application is one in which the PCBs are held
completely within the equipment.
 Under ordinary circumstances, no PCBs would be available
for exposure to the user or the environment.
 However, PCB emissions may occur during equipment
servicing/repairing and decommissioning, or as a result of
damaged equipment.
 The two most significant examples of closed PCBapplications
are capacitors and transformers.
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 Electrical transformers
 Electrical capacitors:
 Power factor capacitors in electrical distribution systems
 Lighting ballasts
 Motor start capacitors in refrigerators, heating systems, air conditioners,
hair dryers, water well motors, etc.
 Capacitors in electronic equipment including television sets and
microwave ovens
 Electrical motors (minor usage in some specialized fluid
cooled motors)
 Electric magnets (minor usage in some fluid cooled
separating magnets)
Closed Applications
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 In general, it is often difficult to determine the presence of
PCBs in sealed equipment, since breaking open the
equipment to ascertain this information will usually be
inappropriate.
 Consequently, the first step should always be to refer to
maintenance records, manufacturers’ literature, trade
associations, and equipment manufacturing companies to
find information on dielectric fluids contained in the product.
Closed Applications
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 Equipment should at a minimum be inspected for any
indications of leaks, such as oil stains near the equipment,
seepage marks on the equipment, or gross physical damage.
 These are signs that the equipment needs to be analytically
tested for PCBs and repaired or possibly replaced.
 Following are useful details for identifying PCBcontamination
in electrical applications.
Closed Applications
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Transformers
 The transformer is a very important component in many
different types of electrical circuits, from small-signal
electronic circuits to high-voltage power transmission
systems.
 The physical size and shape of transformers vary greatly,
from not much bigger than a pea up to the´size of a small
house.
 The main structure of a transformer consists of one or more
electrical coils (or windings) linked together magnetically by
a magnetic circuit or core.
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 For most large transformers, the entire unit is filled with a
dielectric fluid (often an oil possibly containing PCBs) to
increase the insulation between and to cool the electric coils.
 Thus, any damage to the transformer’s outer casing may
result in PCB-fluid leakage.
 It is important to note that although mineral oil transformers
do not intentionally contain PCBs, they often become
contaminated by the use of common filling equipment or
maintenance filling with used or recycled oil.
Transformers
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 Distribution transformers are commonly found near the top
of electric utility poles where they function to lower the
voltage on the distribution line for household use.
 Synthetic PCB-oils are commonly used where fire resistant
transformers are required, as inside buildings and in nuclear
power plants.
 Transformers are also found in many communication circuits
where they function to match a load to a line for improved
power transfer and to improve transmission quality.
Transformers
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 Most transformers are within the control of the electricity
generating and distributive companies, although some
industries privately generate electricity.
 These industries, such as military installations, steel mills,
assembly and manufacturing plants, and railroads, often
have transformers on site.
 Annex A, Tables A.1, A.2, and A.4 provide additional PCBcontaining
transformer identification information, including
common locations, a list of company names that
manufactured PCB-containing transformers, equipment
type designations, and PCB mixture trade names.
Transformers
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Capacitors
 A capacitor is a device for accumulating and holding a
charge of electricity.
 The main structure of a capacitor consists of electrical
conducting surfaces separated by a dielectric material,
frequently a dielectric fluid that may or may not contain
PCBs.
 Typically, a capacitor that contains PCBs is a completely
sealed metal can with two electrical leads or contacts.
 The entire can is usually filled with the PCB-containing
fluid.
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 Identifying capacitors containing PCB dielectric fluids may
be complicated because capacitors are often difficult to
locate.
 They are usually plain boxes that can be remote from
switch rooms or found on individual items within a
building.
 In addition, Annex A, Tables A.1, A.3, and A.4 provide PCBcontaining
capacitor identification information, including
common locations, a list of company and product names,
equipment type designations, production dates, and PCB
mixture trade names.
Capacitors
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 Following are descriptions of three major types/uses of
capacitors that may contain PCBs:
Power Factor Correction Capacitors
 Power factor correction capacitors are large capacitors that are generally
of uniform size (60 cm x 30 cm x 15 cm) and may contain about 1.4 kg of
100% PCB fluid.
 Power factor correction capacitors are usually located near transformers,
often in racks at power stations.
 Potential facilities containing capacitors include factories, offices,
schools, hospitals, stores, and military installations.
 Large capacitors would likely be found near sizable power supply units
within these facilities (e.g., computer equipment rooms, and central
heating and cooling systems).
Types of capacitors
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Motor Start Capacitors
 Motor start capacitors are small capacitors that are used with
singlephase motors to provide starting torque.
 The capacitors can be found in electrical appliances
including hair dryers, washing machines, clothes dryers,
down-well water pumps, ventilating fans, and air
conditioners.
 These small capacitors generally contain less than 1.4 kg of
dielectric fluid.
Types of capacitors
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Light Ballasts
 Lighting ballasts can be found within fluorescent, mercury, and sodium
lighting fixtures, and neon lights.
 Ballasts are composed of a small transformer, a capacitor, and a thermal
cut-off switch.
 The capacitor is the only component that may contain PCBs, typically
approximately 0.1 kg of PCB fluid.
 In fluorescent lights, the ballast is located under the metal cover plate that
is behind the lighting tubes (lamps).
 Ballasts manufactured in the US after 1978 are labeled “No PCBs,” and
therefore any unlabeled ballast from a US source should be assumed to
contain PCBs (US EPA 1993).
Annex A, Tables A.1 and A.4 provide additional PCB identification
information, including common locations, and PCB mixture trade names.
Types of capacitors
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Partially closed applications
 Partially closed PCB applications are those in which the PCB
oil is not directly exposed to the environment, but may
become so periodically during typical use.
 These types of uses may also lead to PCB emissions,
through air or water discharge.
 Examples of partially closed systems include heat transfer
and hydraulic systems, and vacuum pumps.
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Application Typical Location(s)
Heat transfer fluids Inorganic chemical, organic chemical, plastics and
synthetics, and petroleum refining industries
Hydraulic fluids Mining equipment; aluminum, copper, steel, and iron
forming industries
Vacuum Pumps Electronic components manufacture; laboratory, instrument
and research applications; and waste water discharge sites
Switches a Electric utilities
Voltage Regulators a Electric utilities
Liquid Filled Electrical
Cables a
Electric utilities, and private generation facilities (e.g.
Military installations)
Liquid Filled Circuit
Breakers a
Electric utilities
a These applications were not generally designed to contain PCB materials but may have become contaminated
through regular maintenance and servicing.
Partially closed applications
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Open applications
 Open systems are applications in which PCBs are in direct
contact with their surroundings and thereby may be easily
transferred to the environment.
 Direct PCB contact with the environment is of greater
concern for open uses than it is for closed applications.
 Plasticizers are the largest group of open applications and
are used in PVC (polyvinyl chloride), neoprene, and other
chlorinated rubbers.
 In addition, PCBs have been used in a number of other open
uses including in paints as flame-retardants, adhesives as
plasticizers, and in surface coatings as flame-retardants.
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 Lubricants
 Immersion oils for microscopes (mounting media)
 Brake linings
 Cutting oils
 Lubricating oils
* Natural gas air compressors
 Casting Waxes
 Pattern waxes for investment castings
Open applications
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 Surface Coatings
 Paints
* Paint on the undersides of ships
 Surface treatment for textiles
 Carbonless copy paper (pressure sensitive)
 Flame retardants
* On ceiling tiles
* On furniture and walls
 Dust Control
* Dust binders
* Asphalt
* Natural gas pipelines
 Adhesives
 Special adhesives
 Adhesives for waterproof wall coatings
Open applications
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 Plasticizers
 Gasket sealers
 Filling material in joints of concrete
 PVC (polyvinyl chloride plastics)
 Rubber seals
* Around vents
* Around doors and windows
Open applications
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 Inks
 Dyes
 Printing inks
 Other Uses
 Insulating materials
 Pesticides a
a Scrap transformer fluid has been used as an ingredient in pesticide formulas
Open applications
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PCB-containing wastes
Although the manufacture, processing, distribution, and use of
PCBs are widely prohibited, there still exist a host of
different activities that generate PCB wastes, including:
 exemptions given to certain uses of PCBs;
 the incidental production of PCBs;
 recycling operations;
 and quantities held within equipment still in service.
Annex A, Tables A.1 and A.5 provide additional identification
information for PCB-containing wastes, including common locations and
sources.
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Specific examples of activities that generate PCB wastes include:
 PCBs in used oil
 Navigational dredging of PCB-contaminated waters and
sediments
 Repair and decommissioning of equipment
 Building demolition
 Volatilization and leaching from landfills
 Recycling operations
 Incinerators
 Inadvertent production by organic chemical manufacturing
and use industries
PCB-containing wastes
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PCB in used oil
 Because PCBs were widely used in equipment that is still in
service today, waste oil collected from this equipment
frequently contains detectable PCB concentrations.
 PCB-contaminated used oil comes principally from industrial
and automotive sources and electrical equipment.
 Industrial sources are typically plants and factories where
used oil is used as a fluid in hydraulic and heat transfer
systems.
 Used PCB transformer oil has often been mixed with used
mineral oil in oil recycling operations, such that low
concentrations of PCBs are often found in recycled oil used
in trucks and automobiles.
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 Automotive sources are generally gasoline stations and
commercial vehicle fleets that collect oil from engine
crankcases, transmissions, radiators and other vehicle-related
systems.
 In addition, the condensate in natural gas pipelines can
become contaminated with PCBs by contacting PCB
containing oils used in the compressors of such pipelines.
 Users of waste oil should use the tests to determine PCB
presence and concentration.
PCB in used oil
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Navigational Dredging of PCB-Contaminated Waters
and Sediments
 Over the years, large quantities of PCBs have been
discharged into aquatic environments including rivers,
lakes, and estuarine systems.
 PCBs tend to adsorb strongly to sediments.
 Dredging of the bottom to allow ship navigation can
therefore generate waste sediments contaminated with PCB
levels above 50 ppm.
 PCBs were used in hydraulic fluids in mining equipment
and this use was one of the major sources of PCBs that have
settled in river water and river sediments.
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Repair and decommissioning of equipments
 The repair and maintenance of PCB-containing equipment is
a source of toxic waste.
 For example, in the event of a breakdown, transformers are
repaired either by the manufacturer or, more often, in repair
shops which creates PCB containing wastes at these
locations.
 Additional significant sources of PCBs may include waste
materials generated by cleanup of dielectric fluid leaks at
industrial facilities and the explosion or overheating of
transformers and capacitors.
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 Furthermore, the decommissioning of PCB-containing
equipment may introduce (formerly contained) PCBs into the
environment, often in the form of fluff (waste including
upholstery, padding and insulation materials derived from the
shredding of cars and electrical appliances).
 Given that transformers and electrical capacitors tend to have
relatively long service lives (~ 40 years), the PCBs used in
these applications will continue to present a disposal problem
well into the next century.
Repair and decommissioning of equipments
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LTR2 (Low Temperature Rinsing and Re-use) system of
ABB
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Building demolition
 In general, large amounts of waste are produced through the
demolition of buildings.
 Of this waste, PCBs are to be found in filling material for
joints of concrete structures, flame-retardant coatings on
ceiling boards (or tiles), fluorescent light ballasts, coatings
on furnishings, surface treatments for textiles, adhesives for
waterproof wall coatings, paints, insulating materials,
sealant putties, and large and small capacitors (found in
appliances and electrical devices).
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Volatilization and leaching from landfills
 Of the PCBs that have already been disposed, most have
likely been deposited in landfills, including municipal,
industrial, and sewage sludge landfills.
 However, PCBs may be released from these landfills by
volatilization into the atmosphere and leaching into
groundwater.
 It is likely that much of the PCBs distributed in the waste
was originally enclosed in containers, such as capacitors, or
was in plasticized resins and will not be released to the
environment until the containing medium decays or is
damaged.
 Thus, the diffusion of PCBs from landfills is likely to be slow.
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Recycling operations
 Through various recycling operations, PCBs have found their
way back into the commercial stream.
 For example, waste paper supplies (carbonless copy paper)
may have been recycled into paper and board used as food
packaging materials.
 Another major pathway of PCB environmental exposure is
through scrap and waste oil recycling.
 Additionally, recycled PCB-containing mixtures have been
detected in formulations for pesticides and soft soap.
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Incinerators
 Emissions of PCBs may occur during the incineration of
industrial and municipal waste (e.g., refuse and sewage
sludge incinerators).
 Most municipal incinerators are not effective in destroying
PCBs.
 It is recommended that destruction of PCB-contaminated
waste should be carefully controlled, especially with regard
to the burning temperature (above 1 100 °C), residence time,
and turbulence.
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Inadvertent production by organic chemical
manufacturing and use industry
 There are a number of industrial processes in the organic
pigment, pesticide, chemical, and aluminum refining
industries that inadvertently produce PCB-laden materials.
 PCBs can be produced when chlorine, hydrocarbon, and
elevated temperatures (or catalysts) are present together.
 Approximately 90 percent of this production is expected to
contain less than 50 ppm of PCBs, and approximately 5 – 10
percent may contain between 50 and 500 ppm of PCBs.