Final Project report

JAPAN INTERNATIONAL COOPERATION AGENCY
EGYPTIAN ENVIRONMENTAL AFFAIRS AGENCY
THE GOVERNMENT OF THE ARAB REPUBLIC OF EGYPT
REGIONAL ENVIRONMENTAL
MANAGEMENT IMPROVEMENT PROJECT
REPORT
ON
PCBS SURVEY
IN
SHUBRA EL KHEIMA CITY IN
ARAB REPUBLIC OF EGYPT
March 2008

Regional Environmental Management
Improvement Project in the Arab Republic of Egypt (REMIP)
Preface
With the rapid industrialization, the Arab Republic of Egypt suffers damages from environmental
pollution. So far, the Egyptian Environmental Affairs Agency (EEAA), under the Ministry of State for
Environmental Affairs of the Government of the Arab Republic of Egypt (GOE) has developed basic
environmental monitoring capacity for air and water quality, through the technical cooperation by the
Government of Japan (GOJ) and assistance from other donors.
Since GOE requests GOJ further technical cooperation on 1) monitoring-data interpretation and
countermeasures proposal capacity of EEAA, 2) hazardous substance management of EEAA, and 3)
public awareness raising and training to external stakeholders of EEAA, due to their importance, GOJ
has started a technical cooperation project, named “Regional Environmental Management
Improvement Project (REMIP)” since November 2005.
Under the REMIP, Hazardous Substance Management Department in EEAA is carrying out a
component, named “Sound Management of Hazardous Chemical Substances” with relevant
stakeholders, such as Regional Branch Offices (RBOs), Envirometal Management Units (EMUs), and
Non-governmental Organizations (NGOs).
In the first phase of the component, polychlorinated biphenyls (PCBs) were set as the target substances
to be addressed, because GOE rectified the Stockholm Convention in May 2003, and requirement of
inventory survey was stated in the National Implementation Plan (NIP) reported in 2005.
The following works were planned to be implemented under REMIP.
- Collect information of previous inventory survey
- Implement a pilot inventory survey and monitoring work with awareness raising activity for
relevant stakeholders
- Review existing environmental and health guidelines and Japanese PCBs relevant management
system
- Formulate database of articles containing PCBs with relevant information
As a site for pilot inventory survey, Shubra El Kheima City in Qalyubia Governorate was selected.
The city location lies to the north of the centre of Cairo, as shown on the next page, where is a
complex of residential, agricultural and industrial area, suffering from pollution.
This report describes the activities and outcomes obtained through REMIP, and recommendations on
future activities toward sound management of articles contaminated by PCBs.

Location Map of Pilot Inventory Survey Site
Shubra El Kheima City in
Qalyubia Governorate

Nasr City Transformers Storage Site Nasr City Transformers Storage Site
6th October City Transformers Storage Site Bahtim Transformers Storage Site
PCBs Inventory Survey PCBs Inventory Survey
Relevant Activities Implemented in PCBs Inventory Survey and Monitoring Work under
Regional Environmental Management Improvement Project (REMIP)

Awareness Workshop for Local Stakeholders Meeting with Local Stakeholders before
Starting Inventory Survey
Internal Meeting for Expanding of PCBs
Inventory Survey
Internal Training with Local Expert
Analytical Training for Pre-treatment and
Analysis of PCBs
Hazardous Chemical Substances Database
(under preparation)
Relevant Activities Implemented in PCBs Inventory Survey and Monitoring Work under
Regional Environmental Management Improvement Project (REMIP)

i
PCBs INVENTORY SURVEY AND MONITORING WORK
IN
SHUBRA EL KHEIMA CITY IN ARAB REPUBLIC OF EGYPT
Table of Contents
Ⅰ PCBs Overview
1.1 History .................................................................................................................................. 1
1.2 Chemistry ............................................................................................................................. 6
1.3 Toxicity ................................................................................................................................ 12
1.4 Electrical Transformers ........................................................................................................ 17
1.5 Safety Management .............................................................................................................. 23
1.6 Destruction and Decontamination ........................................................................................ 26
II Survey Work
2.1 Previous Inventory Survey ................................................................................................... 33
2.2 Previous Research Studies ................................................................................................... 37
2.3 Law Framework ................................................................................................................... 40
2.4 Environmental, Health and Safety Guidelines ..................................................................... 42
2.5 PCBs Treatment Framework in Japan .................................................................................. 52
2.6 Analytical Aspects ................................................................................................................ 57
2.7 PCBs Inventory Survey ........................................................................................................ 59
2.8 Monitoring Activities ........................................................................................................... 67
2.9 Awareness Activities ............................................................................................................ 72
2.10 Database Formulation .......................................................................................................... 76
III Conclusion and Recommendation
3.1 Conclusions .......................................................................................................................... 77
3.2 Lessons Learned from REMIP ............................................................................................. 77
3.3 Recommendations ................................................................................................................ 78
3.4 On-going Sustainable Efforts ............................................................................................... 79
Personnel

ii
Attachment
Attachment -1 Inventory Survey Results
Attachment -2 Chromatograph of PCBs Analysis
List of Tables
Page
Table 1.1 Fractions Separated in Production Process .................................................................... 10
Table 1.2 Outline of PCBs Destruction and Decontamination Processes...................................... 27
Table 2.1 Concentrations of PCBs (ng/l) during 1990s in Seawater.............................................. 38
Table 2.2 Mean concentrations of PCBs (ng/g dry weight) during 1990s in Sediments ............... 38
Table 2.3 Obligations Defined by “PCBs Special Measures Law” in Japan ................................. 52
Table 2.4 Standard for Treatment of PCBs Wastes ........................................................................ 52
Table 2.5 Outline of PCBs Treatment facilities under JESCO....................................................... 53
Table 2.6 Treatment Method Utilized in PCBs Waste Treatment Facilities in Japan .................... 54
Table 2.7 Safety Management Measures Adopted in Tokyo Facility ............................................ 56
Table 2.8 Outline of PCBs Inventory Survey and Monitoring Activity from
January 2006 to January 2008........................................................................................ 59
Table 2.9 Shubra El Keima City.................................................................................................... 60
Table 2.10 List of Inventoru Sruveyor............................................................................................. 61
Table 2.11 Training Provided under REMIP ................................................................................... 62
Table 2.12 List of facilities Surveyed .............................................................................................. 63
Table 2.13 Number of Transformers Found..................................................................................... 64
Table 2.14 Number of Samples Taken............................................................................................. 67
Table 2.15 List of Analyzed Transformer Oil Samples.................................................................... 67
Table 2.16 List of Analyzed Soil Samples....................................................................................... 68
Table 2.17 List of Analyzed Sediment Samples .............................................................................. 69
Table 2.18 Analytical Results of PCBs in Transformer Oils ........................................................... 69
Table 2.19 Comparison between PCBs Concentration Analyzed and Treatment Standard
Designated by Several Developed Countries and International Donors ........................ 70
Table 2.20 Analytical Results of PCBs in Soils............................................................................... 70
Table 2.21 Analytical Results of PCBs in Soils............................................................................... 71
Table 2.22 Analytical Results of PCBs in Sediment........................................................................ 71
Table 2.23 Target of Awareness Activities....................................................................................... 72
Table 2.24 Design of Awareness Activities...................................................................................... 73
Table 2.25 Outline of Awareness Activities..................................................................................... 74
Table 2.26 Outline of Awareness Raising Workshops ..................................................................... 74
Table 2.27 Outline of Internal Meeting for Awareness Raising....................................................... 75

iii
List of Figures
Page
Figure 1.1 PCBs Molecular Structure ............................................................................................. 1
Figure 2.1 Location of PCBs Treatment facilities under JESCO .................................................... 53
Figure 2.2 Flow of PCBs Treatment in Tokyo Facility ................................................................... 55
Figure 2.3 Flow of PCBs Treatment in Tokyo Facility ................................................................... 55
Figure 2.4 Safety Management Measures in Tokyo Facility........................................................... 56
Figure 2.5 Shubra El Keima City.................................................................................................... 60
Figure 2.6 Draft Framework Proposed for Hazardous Chemical Substance Database ................... 76

iv
Abbreviations and Acronyms
B BAT Best Available Techniques
C CC Coordination Committee
CCC Cairo Central Center, EQS
CIDA Canadian International Development Agency
CO2 Carbon Dioxide
D DANIDA Danish International Development Agency
DMU Mobile decontamination unit
E EEAA Egyptian Environmental Affairs Agency
EEC European Economic Community
EC European Community
ECD Electron Capture Detector
EMD Environmental Management Department, RBO
EMUs Environmental Management Units, Governorates
EQD Environmental Quality Department, RBO
EQS Environmental Quality Sector, EEAA
EREMIS Egyptian Regional Environmental Management Information System
F FDA US Food and Drug Administration
G GC Gas Chromatograph
GEF Global Environmental Fund
GIS Geographical Information System
G GC Gas Chromatograph
GOE Government of the Arab Republic of Egypt
GOJ Government of Japan
H HVAC High-voltage alternating current
I IFC International Finance Cooperation
J JESCO Japan Environmental Safety Cooperation
JICA Japan International Cooperation Agency
K KPEG Polyethyleneglycol and potassium hydroxide
M MESA Ministry of State for Environmental Affairs
N NGOs Nongovernmental Organizations
NOAA National Oceanic and Atmospheric Administration
O OJT On the Job Training
OECD Organisation for Economic Co-Operation and Development
OSPAR Protection of the Marine Environment of the North-East Atlantic
P PAHs Poly-cyclic Aromatic Hydrocarbons
PCBs Polychlorinated Biphenyls
PCBTs Pentachlorobenzenethiols
PCCYs Polychlorinated chrysenes
PCNs Polychlorinated naphthelenes
PCPs Polychlorinated biphenylenes
PCPYs Polychlorinated pyrenes
PCQs Polychlorinated quaterphenyls
PCQEs Polychlorinated quaterphenyls ether
PCTs Polychlorinated terphenyls
PCDDs Polychlorinated Dibenzo dioxins
PCDFs Polychlorinated Dibenzofurans
PCR Post-combustion recombination
PEG Polyethyleneglycol
PICs products of incomplete combustion
POPs Persistent Organic Pollutants
R RBOs Regional Branch Offices
REMIP Regional Environmental Management Improvement Project
S SRBA Sector for Regional Branches Affairs (in EEAA)

v
T TEQ Toxic equivalent factor
U UNEP United Nations Environment Programme
USA United State of America
USD United State Dollar
W WB World Bank

Regional Environmental Management Report on PCBs Survey in
Improvement Project in the Arab Republic of Egypt (REMIP) Shoubra El Kheima City
March 2008
1
Ⅰ PCBs Overview
1.1 History
The time characterizing the "Polychlorinated biphenyls (PCBs) problem" spans over three
centuries, from 1867, with first laboratory synthesis by Griefs in Germany.
The PCBs are characterized by extraordinary features that resulted in a large commercial
application. In 1927, first industrial application by Swan and later Monsanto in USA, starting
from 1930s, a minimum 1 million tons of PCBs have been manufactured.
The chemical stability and relative non-flammability features of PCBs created the decisive
technological innovation to the point that the considerable use was generated by the electro
technical industry.
PCBs different from the commercial mixtures can be generated as sub-products of chemical
processes with chlorinated compounds, i.e. solvents, and/or secondary reactions from
intermediate processes with solvents, i.e. 2,4 dichlorophenol, capable of forming several tens
of ppm of PCBs in basic materials.
PCBs produced from 1930s to 1980s worldwide might reach 1.5 million tons. A considerable
part of which has been dispersed into the environment, where the largest amount of PCBs
based mixtures have been used for so-called "closed" systems, as insulating liquid in
electrical transformers and capacitors. It is estimated that about 30 million of such units are
in operation worldwide. Such compounds of a synthetic origin, have been produced and used
in various commercial mixtures at an international level ever since.
Source: Guidelines for the Identification of PCBs and Materials Containing PCBs
Figure 1.1 PCBs Molecular Structure
(1) Health and environmental risks
The PCBs, polychlorinated biphenyls, in insulating oils and liquids used in electrical
equipment for the generation, transmission and distribution of electricity can determine an
unreasonable risk for human health and the environment caused by their persistency and
bio-accumulation along the food chain. US Food and Drug Administration (FDA) found that

March 2008
2
several accidents involving PCBs had contaminated animal feed and subsequently the
poultry and eggs intended for human consumption.
The discovery of its incompatibility with biosphere resulted in their designation as an
environmental pollutant. "PCBs Risk" was recognized as a global problem over three
decades. The first discovery in the environment was in 1966 by Jensen in Sweden.
PCBs were the subject of an increasing number of papers reported in the scientific literature
dealing with the environment between 1970 and 1971. A conference which dealt with the
environmental problem of PCBs was held in September 1970 in Sweden and in August 1971,
an environmental quality workshop was convened in Durham, New Hampshire by the
National Academy of Science.
The first serious accident was in Yusho 1969, Japan, where 31,180 persons were involved by
intoxication with 26 deaths as a consequence of a leak of PCBs from a heat exchanger into
rice oil.1
The common symptoms included acne form eruptions, hyper pigmentation of the
skin, nails and mucous membranes, swelling of the upper eyelids, and hyper-emia of the
conjunctivae. The highest concentration was found to be 3,000 ppm PCB in oil. A typical
quantity of individual oil consumed was 800-1200 ml containing about 2 g of PCBs. For
victims who had ingested more than 720 ml of oil, the attack rate of Yusho symptoms was
100%.
Other parts of the survey indicated that the use of PCB-containing coatings on the inner walls
of grain silos had been responsible for PCB residues in milk derived from dairy cows which
fed on the grain stored in such silos. The FDA concluded that it would be in the best interest
to limit the ways in which PCBs might enter the food chain as well as limit the levels of
PCBs in food.
The risks generated by PCBs in the ecosystem resulted in the promulgation of numerous
rules at international level on the prohibition and use of these substances,1976-EEC
Directives 76/405 and 79/769, USEPA 1979 40 FR Part/761, Protocol of Stockholm, 22
May 2001 on POPs, which entered into force on 17 May 2004.
PCBs risk can be focalized and prioritized upon:
- Large operators of generating, transmission and distribution of electricity with power plants
and HV/MV/LV substations.
- Large users of electricity such as cement factories, steel mills, petrochemical industries, etc.
- Multi-utilities providing vital services, such as water, gas, waste disposal etc.
- Vital infrastructures, such as airports, mass transit, hospitals etc.
- Waste and machinery de-commissioning handlers.
A concentration of PCBs of about 30-80 ppm has typically been found in decommissioned
vehicles causing the classification of the "fluff" as PCBs waste that cannot be landfilled, but
disposed of or treated as dangerous waste at unexpected higher costs.
1
Oil extracted from rice polishings

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(2) PCBs compounds
Insulating liquids and equipment containing insulating liquids are classified, respectively,
"PCBs" and "Equipment containing PCBs" when the total concentration of polychlorinated
biphenyls, 209 possible congeners, and correlated compounds PCTs, poly-chlorinated
terphenyls, 8,557 possible congeners, and PCBTs, polychlorinated benzyltoluenes, thousands
of possible congeners, present in the insulating liquids exceeds the limits prescribed by
current legislations for the single matrices or destinations, equipment and insulating liquids
in operation, used oils, fuel oils, etc.
A study of 1988 in USA estimated that there were about 2.6 million transformers
contaminated with concentrations between 50 and 500 ppm and about 266,000 transformers
with concentration over 500 ppm. It is reasonable to believe that a considerable quantity of
those transformers is still in operation. The amount of PCBs used in transformers and
capacitors in EEC countries for 1996 is estimated in 200,000 tons, 60,000 of which are still
used in open systems. Small capacitors are about 700,000 with an average content of 10 g of
PCBs per unit.
In Italy the largest share, about 60-70 % of the existing PCBs is concentrated with the
producers and grids of electricity and contaminated transformers the largest industrial sites,
such as steel and cement factories, whereas the remaining 30-40% is scattered on the
territory, with small and medium companies and public structures where the hazard of fires
can create a substantial risk, i.e. hospitals and schools.
(3) Contamination by PCBs
"Equipment containing PCBs" means any equipment containing PCBs or used to contain
PCBs, e.g. transformers, resistors , inductors, reactors, switches , capacitors receptacles
containing residual stock, etc., which have not been decontaminated. Equipment of the type
which may contain PCBs shall be treated as if it contains PCBs unless it is reasonable to
assume the contrary. If the equipment cannot be accessed or it is difficult to take samples due
to operational requirements or any other reason, the equipment should be considered as
"containing PCBs". The determination of the concentration of PCBs in insulating liquids is
recommended in case there are reasons to believe that the content of PCBs could have been
changed as a result of maintenance operations, and in case of end-of-life and disposal of the
equipment or the fluid, and the content of PCBs is not already known.
The mass of contaminated oil, just in the OECD Countries, is estimated in several million
tons.
The main sources of fluid contamination by PCBs are multifold:
- Use of contaminated equipment.
- Regeneration and recycling of used oils contaminated by PCBs.
- Human errors, lack of information, criminal acts of negligence.
- Lack of appropriate equipment for the treatment of contaminated liquid.
- Inappropriate conduct by the manufacturers of new equipment using components salvaged
from old equipment.

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4
The management of insulating liquids has been developed in accordance with the following
motivating principles:
- Reduction of risks for workers, public health and the environments, deriving from troubles
or failures of the equipment that could originate fires or the spill of hazardous and persistent
products.
- Implementation of the "Best Available Techniques (BAT)" and methodologies available for
safety, self-sufficiency and functional recovery.
- Technical feasibility of the activities recommended or imposed by current legislation,
within the prescribed time schedules, taking into account the economic feasibility as well.
The Directive 96/59 EC of 16 September 1996 defines stricter regulations relative to the
inventory, control and management, article 4, the decontamination and/or disposal of the
PCBs equipment within 2010, article 3.
(4) PCBs problem
During their life cycle, systems, equipment and insulating liquids in operation can degrade
faster, if not properly managed and maintained, inducing failures that could cause, under
limited circumstances, incidents having a significant environmental impact, that can be
correlated to the specific conditions of the settlement and the site. In the event of
uncontrolled thermal oxidation, during the operation of transformers, in hot spots from 150
to 300o
C, or in case of failures, arching of electrical systems, with explosions and fires,
significant concentrations of very dangerous compounds occur, such as PCDFs-Furans, 135
congeners, and PCDDs-Dioxins, 75 congeners. The degradation process of the materials of
the equipment and spillage of PCBs liquids into the environment is estimated at about
0.1-0.5% yearly of the average volume filling the unit. Thus, during their service life,
equipment containing PCBs should be subject to measures capable of preventing and/or
mitigating degradation processes and the spillage of PCBs to ensure the protection of
workers, public health and the environment, as well as complying with the prescription of the
Stockholm Convention entered into force on 17 May 2004.
(5) Limits of PCBs-contaminated equipment
Any mixture of substances with a volume exceeding 5 dm3
(5L), with a concentration
exceeding 0.005% (50 ppm) of PCBs, polychlorinated terphenyls, PCTs, monomethyl-
tetrachlorodiphenyl methane, PCBTs, monomethyl-dichloro-diphenyl methane,
monomethyl-dibromo-diphenyl methane. Consequently it is defined as PCBs the summation
of PCBs, 209 congeners, PCTs equivalent, 8,557 possible congeners, and PCBTs, several
thousand possible congeners. The subject classified as PCBs must be labelled and reported to
the legitimate authorities. Transformers subject to inventory containing insulating liquids
contaminated by PCBs to 500 mg/kg, 500 ppm, may be kept in operation up to the end of
their operational life. Transformers subject to inventory containing insulating liquids
contaminated by PCBs in excess of 500 mg/kg, 500 ppm, must be disposed of or
decontaminated. If the limit of 5L is not known or can not be presumed from the data of the
plate or other documents of the manufacturer, it should be referred to the total volume of the
equipment.

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5
(6) Importance of diagnosis and monitoring PCBs-contaminated equipment
The fleet of electrical equipment represents a considerable monetary and strategic value. A
global approach toward an "asset management approach", under financial, technical and
statutory viewpoint is fundamental, based upon two strategies:
- A strategy for the inventory of PCBs/PCTs/PCBTs.
- A strategy for the diagnosis of functional degradation.
For a correct interpretation of the results of the analyses, specific standard references are not
always available, thus it is essential to plan the monitoring activity in systemic form and to
evaluate the evolution through time, rate, trend, of the parameters and the correlation with
statistical data of population of reference. The interpretation of the test results and the
relevant diagnosis of the functional degradation of the transformer and insulating liquid
should be performed by expert and qualified operators. Evaluation of trend analysis and
velocity of variation of the concentration of compounds are correlated to degradation,
dissolved gases, water, etc. Normal or typical values, alert or alarm values recommended
deducible from the applicable technical standards for the type of equipment and/or family of
belonging are considered. Recently, “intelligent systems" are carried out performing a
diagnosis and evaluation of symptomatic trends. The path, under evolution, should lead to
the development of algorithms, typically computerized, capable of "learning" from experts
during an initial phase, and then enter a self-learning phase, evolving into really expert
systems, capable of learning, similar to mankind, from their own experience extrapolating
correlations from the data in their databank.

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6
1.2 Chemistry
Compounds of concern can be contained in PCBs-containing fluids for a variety of reasons.
For example, they may be formed from impurities in the feed stock used to manufacture
PCBs, cyclization of PCBs include by heat, or from phenolic or other precursors.
 Aliphatic chloro-compounds can produce aromatic chlorinated pyrolysis products:
· Hexachlorobenzene crystals were formed by heating dichloroacetylene
(perchlorocarbons) and also hydrocarbons which have had all of the replaceable
hydrogen substituted by chlorine.
ClC CCl C2Cl6 C2Cl4 + C6Cl6
· The chain chlorination of aromatic compounds takes place by two possible
mechanisms: an addition, which proceeds through an intermediate cyclodiene
compound, or an abstraction one, which occurs through intermediate phenyl
radicals.
 Formation by pyrolysis of chlorobengene, dependence upon temperature pyrolysis: a
reductive Atmosphere, i.e. less oxygen
· Pyrolysis of chlorobenzenes at 600oC in the presence of air more than 1%
tetra-to-octa chlorodibenzo furans (CDFs) and tetra-to-octa
chlorodibenzodioxins (CDDs)
 Formation of polychlorinated biphenylenes (PCPs) as a result of the reductive
conditions which occur in the early stages of askarel transformer fires. Because of their
structure, are expected to be as toxic as the correspondingly substituted PCDDs.
 Formation of polychlorinated pyremes (PCPYs) and polychlorinated chrysemes
(PCCYs) as components
 Formation of polychlorinated dibenzo furans (PCDFs) from the pyrolois is of PCBs:
The yields were from 1 to several % (different out)
· Intermolecular four alternative reaction routes → different isomeric PCDF
products.
· There is a connection between the toxicity of degraded PCBs fluids, including
tri-/ tetra-chlorinated benzene/PCBs blends, and the concentration of PCDFs.
 Formation of polychlorinated (terphenyls, quaterphemyls and maplthalenes) from
chlorination of a feedstock contaminated by traces of the aromatic hydrocarbons:
· Polychloronaphthalenes (PCNs) have been identified as a pyrolysis product from
an askarel transformer fine. By invoking the formation of benzene intermediates
or the rearrangement of intermediates formed between an ortho-chloro phenyl
radical with a chlorobenzene i.e. the overall effect of radical reactions on the
product distribution during askarel degradation will be effected by both
temperature and the availability of oxygen. Less than 600 ppm is found in
commercial PCBs due to maphthake impurity in bizhemyl raw material.
· A correlation was found between the concentrations of terchlorodibenzene forms
(TCDFs) in used askarel with the length of time the fluid had been is service.
heat heat

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7
· Transformer units with extreme overloads would be expected to overheat and
fail. The most probable cause of eventful transformer failure is violent rapture
and the quantities of any compounds of concern which may be produced is
determined by availability of oxygen in an oxygen depleted, high temperature
reaction zone of short duration.
N.B.: the power transformer Guide: ANSI-C57.92-1981 lists a maximum top oil limit of
110o
C which may occur when the maximum hot spot conductor temperature is at 180 o
C due
short term loading.
The distribution transformer Guide ANSI C57.91-1974 lists a maximum top oil temperature
of 120 o
C which may occur at maximum conductor hot spot temperature of 200 o
C
Incineration of PCBs:
Several physico-chemical factors influence incineration: exposure temperature, the oxygen
composition of flame and non-flame atmospheres, gas phase residence times in different
heated zones, oxygen concentrations and associated gradients, presume, flame contact time,
spatial and temporal variations in temperature, thermodynamic and kinetic properties of the
compounds involved.
Thermal degradation of PCBs:
It can result in a complex set of reactions which may produce compounds of concern under
uncontrolled conditions including the possible formation of dioxins. Temperature and
residence time relationships have been extensively studied to establish the conditions
necessary for satisfactory destruction. A 1 s residence time resulted in that most PCBs
decomposition occurred in a temperature range between 640 o
C and 740 o
C.
Commercial incineration equipment for the destruction of PCBs must be designed so that the
energy input to disrupt the molecule is made available either by supplying a very high
temperature or a satisfactory long residence time. The intractability of the mathematics used
to model such systems depends to some degree upon the number and type of simplifying
assumptions which are applied. Several types of incinerator are found useful for this purpose
and include rotary kilns, high temperature find wall reactors, plasma pyrolysis units,
circulating bed combustors, etc.
 Formation of chlorophenols, a side reaction product has the potential to generate PCDFs
and/or PCDDs in the following ways:
· dimerization of chlorophenate.
· cycligation of polychlorinated biphenyl ethers (PCDPEs).
· cyclization of polychlorinated phenoxy phenols.
The pyrolysis of PCDPEs follows two competitive reaction pathways, reduction
dechlorination or ring closure to PCDFs.
 Formation of PCDDs by dimerization of trichlorophenol, produced from reacting
tetrachlorobenzene with NaOH in ethylene glycol; (Seveso accident, 1976) liquid
system: reactants are retained in the reaction zone for periods of time which are long
compared to the time required for the formation of product. Gaseous system: as in a
flame, the reaction zone is relatively short-lived and the yield of product is therefore
less.

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8
· The importance of even statistically unlikely reactions lies in the toxicity of the
products.
· Formation of PCDDs by cyclization of polychlorinated phoenix phenols, a
bimolecular reaction under the influence of heat.
· Formation of PCDFs occurs at 700-800? c and their yield increases up to about
900 o
C. Above 900 o
C, there is rapid decomposition of both the PCBs and the
PCDFs.
Dechlorination of PCBs:
It involves an initial addition of an electron to the aromatic molecule. The end result of the
reaction should be that there is no remaining organically bound chlorine. However,
depending upon the chemistry involved and the stoichiometric excess of reagent , toxic
intermediates can be produced which, while satisfying the requirements for the removal of
PCBs, can produce a severe problem where only a relatively slight hazard existed before the
process was applied.
From a chemical point of view there is a little difference between whether the electron is
derived from an alkali metal or an organometallic reagent or from radiation induced
electrons.
Co60
gamma-rays were used to induce electrons in deoxygenated solutions of PCBs in
alkaline isopropanol. The presence of small amounts of electron acceptors resulted in an
inhibition of dechlorination. The formation of chloride, Cl, ion and the consumption of
hydroxide ion, OH-
, were approximately equal at each dose.
Transformer askarels were irradiated in dielectric insulating oil with 2MeV Sr90
β-particles.
Dechlorination reaction did occur but that, in the absence of KOH and isopropanol, the
degradation required impractically long irradiation times. The β particles radiolysis of water
produces hydroxyl radicals, OH-,
and solvated electrons. The solvated electrons react with
PCBs to give a PCBs radical anion. The anion stabilizes itsell by eliminating chlorine as
chloride ion to leave a PCBs radical.
 Hydroxyl radicals are extremely reactive species and are produced in very small
amounts relative to the iropropanol present. It is consequently more likely that reaction
will take place with isopropanol than with a small amount of PCBs or an even smaller
concentration of PCBs radicals. Also, the concentration of PCBs radicals is so small
relative to the macro amount of isopropanol present, that coupling to produce a
polychlorinated quaterphenyl is unlikely.
 Mixtures of PCBs are destroyed by β-particle radiolysis most efficiently when the
solution is free of oxygen and contains an alkaline hydrogen donor to allow free radical
chain propagation.
 In the absence of isoprepanol and hydroxyl anions the radidysis reaction requires very
much larger irradiation dose and hence very much longer reaction times under these
circumstances the concentration of hydroxyl radicals which are produced is similar to
the concentration of PCBs radicals and hydroxylation occurs to give a polychlorinated
phenol. Intermolecular cyclization of the hydroxyl Ted intermediates can occur to yield
PCDDs (Cyclization of polychlorinated phenoxy phenol)

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9
 In the presence of the H-donor, isopropanol, the PCBs radical can easily abstract
hydrogen to become a PCBs molecule with one less chlorine than at the beginning of
the reaction sequence.
 The isopropanol radical formed in the hydrogen abstraction step reacts with the
hydroxyl ions from the KOH in the system to produce acetone radical ions.
 The acetone radicals become stabilized as acetone after interaction with PCBs to yield
PCBs radical anions.
 The reaction sequence contains in this way until total dechlorination has occurred.
Dechlorination by sodium dispersion:
This was first applied by Japanese workers in 1973. The method was applied in the
decontamination of electrical insulating oils by Webber et al, who found that even high
concentration of askarel would react to give a non-toxic polyphenyl sludge.
It was postulated that chlorinated biphenyl radical anions are produced by interaction of the
PCBs molecule in solution with metallic sodium in suspension. The radical anion eliminates
chlorine as chloride to form a chlorohiphenyl radical which, in turn, abstracts available
hydrogen from oil components to yield partially dechlorinated PCBs. The reaction contains
in the presence of a stoichiometric excess of sodium until total dechlorination is achieved.
In the absence of a readily available quantity of abstractable hydrogen, from oil components,
the biphenyl radicals tend to couple and form quaterphenyls and higher polyphonys. The
reaction is relatively less likely to occur than the dechlorination reaction when an excess of
sodium is present and consequently the quaterphenyls which are formed either have few
remaining chlorine atoms on the rings or are completely dechlorinated.
The NMR of polymerized biphenyls has indicated that electrical conductivity through the
polymer chains to dependent upon the extent of electron orbital overlap between the ring
constituents of the polymer. Thus, when a small excess of alkali metal reagent is maintained
in contact with insulating oil for a long time, in order to minimize the use of reagent, for
example, polyphony's are produced which are dissolved in oil. the power factor of the
processed oil then increases dramatically to 10% , ASTM D924, compared with that of
useful oil of <0-1%. An increase in power factor corresponds to an increase in the
concentration of polar constituents in the oil.
There are also several classes of polychlorinated aromatic hydrocarbons which may be
contained as impurities or degradation products of PCBs:
· Polychlorinated terphenyls
· Polychlorinated quaterphenys (PCQs), similar toxic as PCBs.
· Polychlorinated quaterphenyl ether (PCQEs)
· Polychlorinated naphthelenes (PCNs)
· Polychlorinated biphenylenes (PCPs)
· Polychlorinated pyrenes (PCPYs)
· Polychlorinated chrysenes (PCCYs)

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Dioxin formation in flames:
· The production of fuel radicals by hydrogen abstraction from fuel is likely to be
slower than the reaction between hydroxy radicals but this reaction will
dominate especially in areas where there are fuels-rich products in the
incineration process.
· Increasing substitution by chlorine in chloroprene's would be expected to result
in slower rates of attack by hydroxyl radical, therefore the more highly
chlorinated dioxins are likely to be less reactive towards bimdecular
decomposition with high hydroxyl radicals than the lesser chlorinated confiners.
One would then expect that the dioxin isomer distribution tend to be skewed
toward higher chlorinated species.
· The phenoxy radical is also produced when hydroxyl radicals cause hydrogen
atom abstraction. If, alternatively, OH addition occurs, then the adduct may
undergo further reaction with oxygen, or some other species, to give ring
opening and thereby reduce the likelihood of dioxin formation.
· Assuming no O2 or fuel is available → formation of dioxin could be
exaggerated.
· Assuming 60% O2 of the value needed → deemphasizing the rate of loss of
chlorophenoxy radical →in favor of dioxin formation.
· Under post-combustion mixing, in an intermediate temperature zone, unburned
chlorophenol is predicted to react with hydroxyl radicals to produce PCDDs.
· Clearly, high temperature, and a sufficient quality of air and fuel are able to
provide conditions which will combust chlorophenols into products which are
not PCDDs.
· Some conditions will allow the formation of PCDDs at concentration which is 5
to 10 orders of magnitude higher than those produced under 'designed' operating
conditions.
Pyrolysis of Coal Tar:
It was used as the source of raw material for the early production of benzene and related
hydrocarbons. The production process relied on temperature to separate products as shown
below.
Table 1.1 Fractions Separated in Production Process
Fraction Temperature Range
(o
C)
Name of Fraction Volume
(%)
1 < 170 Crude light oil 2.25
2 170-230 Middle oil 7.5
3 230-270 Heavy oil 16.5
4 270-360 Anthracene oil 12
5 Pitch ~56
To extract benzene from the crude light oil fraction, it was washed with concentrated
sulphuric acid, water, sodium hydroxide and again with water. The sulphuric acid removes
basic substances such as pyridine while the sodium hydroxide removes phenols.

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When the washed light oil was distilled, the fraction collected up to 110o
C contained about
70% benzene, 24% toluene and some xylenes with other hydrocarbon impurities.
Pure xylene was obtained from the fraction of the light oil distillation obtained between
110-140o
C.The distillate above 140 o
C is known as "solvent naphtha" and consists of xylenes,
cumenes (isopropylbenzenes).
Naphthalene is the largest single constituent of coal-tar (6%). It was obtained from the
middle and oil fractions from the pyrolysis of coal tars. The nephthahene were treated with
concentrated sulphuric acid, washed with water and then sodium hydroxide.
The amount of residual phenol contaminated in the product may have caused the generation
of phenoxy phenols (diphenyl esters) and formed dioxins.
Industrial chlorophenol formulation are often found to contain impurities which, upon
heating can form compounds of concern (hazardous).Typical total concentration of
phenexyphenols and other phenolic dimers in formulations were estimated to be 1.7-2.3%

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1.3 Toxicity
(1) Introduction
The toxicity of PCBs is complicated because PCBs are mixtures and not individual
chemicals. The toxicity of different PCBs mixtures varies because the dose-effect
relationships differ for individual chlorobiphenyls. The more chlorinated PCBs are less likely
to be metabolized in humans and wildlife and, therefore, bioaccumulate to a greater extent.
The less chlorinated PCBs are more water soluble and have shorter half-lives in the body
because of more rapid metabolism and excretion. The greater metabolism and more rapid
excretion of the less chlorinated PCBs dose not necessarily indicate less concern for toxicity,
because some metabolites of these PCBs may also be toxic. Consequently, the health and
ecological risks associated with PCBs mixtures can vary as the chemical composition
changes as a function of space, time and trophic level. Organisms at the top of food chain,
including humans, tend to accumulate PCBs in their tissues, placing them at risk for adverse
health effects.
Risk characterizations should be performed on the basis of specific congeners and the total
mixture of congeners that exist rather than on the basis of "total PCBs" (all PCBs congeners)
or Aroclor (commercial PCBs mixtures). This method will allow for an accounting of the
different congeners in the risk calculations.
Today the major source of ambient PCBs exposure seems to be environmental cycling of
PCBs previously released into the environment. About 450 million pounds have found their
way into the environment. PCBs can be released into the general environment from poorly
maintained toxic waste sites; by illegal or improper dumping of PCBs wastes, such as
transformer fluids; through leaks of fugitive emissions from electrical transformers
containing PCBs; and by disposal of PCBs-containing consumer products in municipal
landfills.
A system of toxic equivalents (TEQs) is used to Standardize the reporting of concentration of
dioxin and furan mixtures to reflect their toxic potential. 17 congeners, the 2,3,7,8 substituted
compounds are assigned a weighed toxic equivalent factor: thus the most toxic,
2,3,7,8-TCDD, is assigned the factor 1, while OCDD, the least toxic is assigned 0.001. The
measured quantity of each congener in the sample is multiplied by its toxic equivalent factor,
and the products are summed to give the TEQ.
(2) Who is at risk?
There is a direct relationship between serum PCBs levels and the quantity of contaminated
fish consumed. Recreational and subsistence fishers who eat large amounts of locally caught
fish might be at increased risk for exposure to PCBs. Fetuses and neonates are potentially
more sensitive to PCBs than are adults because the hepatic microsomal enzymes systems that
facilitate the metabolism and excretion of PCBs are not fully functional. In addition, infants
and young children consume a greater amount of food per kilogram of body weight and
therefore have a proportionately greater exposure to PCBs than do adults eating food with
same level of contamination, and there is placental transfer increasing the body burden.
Persons living near incinerators, other PCBs-disposal facilities, or former hazardous waste
sites at which PBCs have been found are also at increased risk for exposure. Because PCBs
are metabolized mainly in the liver, persons with impaired hepatic function might be at

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increased risk because of their diminished ability to detoxify and excrete these compounds,
as do those with chronic liver diseases such as cirrhosis or hepatitis. Similarly, because
hepatic function normally declines with age, elderly persons are also more susceptible to the
effects of PCBs exposure.
Workers can inhale or have dermal contact with PCBs during the repair or routine
maintenance of older equipment or electrical transformers and during accidents or spills
involving PCBs. Exposure can also occur during the disposal of PCBs-containing materials
at hazardous waste sites:
Electric cable repair, electroplating, emergency response, firefighting, hazardous waste
hauling/site operation, heat exchange equipment repair, maintenance cleaning, medical
laboratory technician/technologist, metal finishing, non-cellulose fiber industry, paving and
roofing, pipefitting/plumbing, semiconductor and related industries, timber products
manufacturing, transformer/capacitor repair, and waste oil processing.
(3) Biologic fate
After first distributing preferentially to the liver and muscle tissue, PCBs are subsequently
redistributed to the adipose tissue, skin and other fat-containing organs.
The rate of individual congener metabolism depends on the number and position of chlorine
atoms. In rats, the half-lives of PCBs congeners range from 1 to 460 days, depending on the
degree of chlorination. In general less-chlorinated isomers are more readily metabolized than
are more highly chlorinated congeners.
Excretion of PCBs is very slow, so bioaccumulation occurs even at low exposure levels.
Background levels of PCBs in human sera are typically <20 ppb and residues measured in
human milk have values ranging from 40 to 100 ppb. Reported; levels in adipose tissue range
from 1 to 2 ppm.
(4) Physiologic effects
1) Dermatologic effects
Chloracne is the only overt effect of PCBs exposure in humans. In a person with
PCBs-induced chloracne, the acneform lesions arise as a result of inflammatory responses
to irritants in the sebaceous glands per orbital. The chin, periorbital, and malar areas is
most often involved, although lesions might also appear in areas not usually affected by
acne vulgaris (e.g., the chest, arms, thighs, genitalia, and buttocks). The most distinctive
lesions are cystic and measure from 1 to 10 mm, although comedonal lesions can also be
present. The cysts and comedones can become inflamed and secondarily infected, and
papules and cysts can be surrounded by edema and erythema. Chloracne typically
develops weeks or months after exposure. The lesions are often refractory to treatment and
can last for years to decades. In addition to chloracne, hyper pigmentation of the skin,
conjunctivae, gingival, and nails, have also been noted in some PCBs-exposed workers.
2) Reproductive and developmental effects
Recent studies indicate that consumption of PCBs-contaminated fish can cause
disturbances in reproductive parameters, although more research is required to assess this
possibility and cause neurobehavioral and developmental deficits in newborns and older

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children. Prenatal exposure to PCBs from the mother's body burden, rather than exposure
through human milk, is believed to account for the developmental effects of these
compounds. Some evidence shows that menstrual cycle length can be reduced with
increased PCBs intake, no significant association was found between low to moderate
PCBs intake and clinically recognized spontaneous fetal death. Developmental and
cognitive deficits were observed in the children of mothers who had eaten moderate to
high amounts of contaminated fish during the 6 years preceding pregnancy and who
continued to do so during pregnancy.
Neurobehavioral deficits included depressed responsiveness, impaired visual recognition,
and poor short-term memory. The infants born to mothers who had eaten the greatest
amount of contaminated fish during pregnancy exhibited weaker reflexes, greater motor
immaturity, and more pronounced startle responses than infants born to woman who had
consumed less fish. Follow-up studies of the children have demonstrated that the effects of
prenatal exposure to PCBs are persistent.
3) Endocrine effects
PCBs have been identified as possible environmental endocrine modulators (chemicals
that mimic or disrupt the action of naturally occurring hormones). PCBs exposure on
endocrine function involves disturbances in processes normally mediated by thyroid and
female sex hormones. The thyroid gland is an unequivocal target of PCBs in rats, and
limited but corroborative occupational data indicate a potential for thyroidotoxic effects in
humans Because thyroid hormones are essential for normal behavioral, intellectual, and
neurologic development, it is possible that the deficits in learning, memory, and attentional
processes observed in the offspring of PCBs-exposed women are partially or
predominantly mediated by alterations in hormonal binding to the thyroid hormone
receptor. Other subsets of PCBs congeners might interfere with the biological effects of
estrogen. Depending on the spatial orientation of their chlorine constituents, some
congeners exhibit weak estrogenic activity, whereas others act as antiestrogens.5)
Endocrine effects
4) Hepatic effects
Histologically documented liver damage is a consisted and prominent finding among
PCBs-exposed animals; however, no evidence of hepatic dysfunction or overt
hepatotoxicity has been seen in PCBs-exposed workers. Asymptomatic hepatomegaly has
been reported in exposed workers, many of whom had concomitant elevated serum PCBs
levels.
Strong evidence shows that exposure to PCBs can increase serum liver enzyme levels.
Some researchers believe that asparatate aminotransferase (SGOT or AST) and gamma
glutamyl transpeptidase (GGTP or GGT) are the most sensitive indicators of PCBs
exposure in humans, and that changes in these enzymes can occur at exposure levels
below those at which chlorance appears.
Increases in urinary porphyrin levels were noted in a study of workers with low-level
PCBs exposure, an effect that is believed to be secondary to the induction of hepatic
microsomal enzymes. Total bilirubin levels exhibit a positive correlation, and serum
albumin a negative correlation, with serum PCBs levels. Microsomal enzyme induction by
PCBs has been observed in the liver of humans and in extrahepatic tissues of animals.
Enzyme induction may affect how rapidly both endogenous (e.g. hormones) or exogenous
substances (drugs, environmental metabolites, etc.) are metabolized.

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5) Carcinogenicity
In studies of occupationally exposed workers, increases in the incidence of malignant
melanoma and cancers of the liver, gall bladder, biliary tract, and brain have been reported.
In persons without known occupational exposure to PCBs, elevations in the serum PCBs
level have been associated with an increased risk of non-Hodgkin lymphoma. Because of
their estrogenic properties, PCBs have also been proposed as possible inducers of breast
cancer; however, the results of epidemiologic studies in PCBs-exposed women have been
inconsistent. Data from animal studies have clearly shown that PCBs cause
hepatocarinomas, pituitary tumors, leukemia, lymphomas, and gastrointestinal tract tumors.
On the basis of these data, EPA considers PCBs a probable human carcinogen.
6) Other effects
Adults who ate fish from PCBs-contaminated waters had significantly greater motor
retardation, poorer results on certain tests of memory and attention, and higher scores on a
standardized confusion scale than did controls, and these neurologic deficts were directly
related to the frequency of fish consumption. In a study of persons living near a hazardous
waste site, the incidence of borderline and definite hypertension was 30% greater among
PCBs-exposed persons than among controls. Immune system effects reported in
PCBs-exposed populations have included decreases in natural killer cell count, decreases
in antibody levels, alterations in the ratio of helper to killer T-cells, and decreases in
monocyte and granulocyte counts. Appetite loss has been reported in transformer and
electrical equipment manufacturing workers exposed to various PCBs-containing mixtures.
Other nonspecific gastrointestinal symptoms include nausea, epigastria distress and pain,
and intolerance to fatty foods.
(5) Clinical evaluation
A detailed history will facilitate the diagnosis of chronic PCBs poisoning. Pertinent
information includes occupational histories of all household members as well as information
on the patient's medications and diet. During the physical examination, physicians should
pay particular attention to the skin and hepatic systems.
1) Signs and symptoms
Acute exposure
The only overt sign of PCBs exposure is chloracne, Acneform lesions do not appear in all
severely exposed patients, so the absence of chloracne dose not rule out exposure.
Elevated liver enzymes are the most sensitive indicator of PCBs exposure in animals, and
alterations in AST (SGOT), GGT (GGTP), bilirubin, and albumin levels have been
consistently reported in human epidemiologic studies. Hepatomegaly has also been noted
in some PCBs-exposed workers.
Chronic exposure
Many people who are chronically exposed to PCBs exhibit no overt signs or symptoms of
toxicity. In persons with hepatic involvement, signs of PCBs exposure can include weight
loss, anorexia, nausea, vomiting, jaundice, and abdominal pain. Headache, dizziness, and
edema have also been reported.

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(6) Laboratory tests
Serum or adipose tissue PCBs levels can indicate exposure, but they are difficult to interpret
clinically. In all but the most extreme cases, therefore, the diagnostic workup should be
limited to liver function tests and dermatologic examination, with skin biopsy of lesions.
PCBs accumulate in breast milk, and breast-fed infants might be at additional risk because
human milk contains a steroid that inhibits PCBs metabolism and excretion. Elevated hepatic
enzyme levels are of limited value in diagnosing exposure to PCBs.
(7) Treatment and management
1) Acute exposure
In the event of PCBs splashes in the eyes, irrigate with tepid water immediately for at least
15 minutes, and follow with ophthalmic evaluation. Remove contaminated clothing and
discard properly. Gently wash affected skin with soap and warm water for at least 15
minutes. In case of ingesting PCBs-containing substances induce vomiting if the patient is
conscious. Gastric lavage can be subsequently administered at a medical facility.
Activated charcoal has not been proven beneficial, but is not contraindicated. Exposed
persons should have periodic follow-up examinations with particular attention to hepatic
function and dermal lesions.
2) Chronic Exposure
The goal of treatment in chronically exposed patients is to prevent any additional exposure
to PCBs. No specific treatment exists for chronic exposure to PCBs, because no known
methods exist for reducing the reserves of PCBs in adipose tissues. In fact, PCBs stored in
fat can be mobilized by the patient's crash dieting. Initial treatment of chloracne is based
on cessation of exposure, good skin hygiene, and dermatologic measures commonly used
for acne vulgaris.

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1.4 Electrical Transformers
(1) Introduction
The determination of the extent of the PCBs problem is conditioned by the uncertain value of
the estimation obtained by the inventories implemented in accordance with current
regulations.
The uncertainty derives from several reasons, such as the scarce interest that the holder of the
substances and materials contaminated by PCBs has in reporting them, since from this action
derive the obligations for a series of periodical checks, a special maintenance to the extent of
decontamination.
The users of large generation and distribution systems and large transmission networks of
electric power can rely on elements of knowledge such as statistics of failures, inspections
performed after events, monitoring systems etc., to evaluate the operational state of the
equipment and insulating liquids. In case the holder is not in the position to comply with the
conditions described here above, the transformer should be decontaminated or disposed of at
once.
Transformers containing PCBs or PCBs-containing liquid should regularly be submitted to
two types of monitoring: visual and analytical tests. Such transformers should be submitted
to more stringent maintenance programs than those considered as not contaminated by PCBs
in order to minimize unreasonable risks to the workers, the public health and environment.
Local regulations should be strictly followed.
In the majority of cases, the equipment subject to diagnosis, transformers, is filled with
dielectric liquids providing insulation and cooling. The main element of the insulating
system, however, is provided by Kraft paper, cellulosic insulator. Also, other solid materials
impregnated by oil are present, cardboard, wood, etc.
Electrical and mechanical, vibrations, as well as thermal and chemical oxidation stresses
cause a degradation of all the elements of the insulating system. The degradation of Kraft
paper and solid insulators is generally caused by thermal events, localized or extensive, and
by mechanical stress, vibration of windings.
The degradation of the paper does not lead to immediate and significant losses of its
insulating features, but to a weakness and decay of its mechanical properties.
The degradation of insulating oil is caused by physical and chemical processes: temperature
and contact with air and atmospheric moisture favor oxidation phenomena and the
contamination of the oil by agents decaying the insulating features, moisture, particles, dust,
etc.
The presence of metal elements facilitates the formation of conductive polar compounds or
the generation of particularly aggressive substances, corrosive sulphur.
Each material generates compounds specific of its chemical structure and of a type and
intensity of the abnormal event it is exposed to. All degradation compounds, irrespective of
the physical position in the transformer originating them, are dissolved or dispersed into the
insulating liquid.
Mineral insulating oil and paper itself originate hydrocarbon gases, methane, ethane,
ethylene, and acetylene, and hydrogen, carbon monoxide and dioxide as a consequence of

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thermal and/or electrical stresses they are subject to. The paper and cardboard making the
insulation of electrical equipment are a further source for the production of gases, as well as
a minor quantity of furanic derived.
(2) Evaluation of degradation
By evaluating the type of dissolved gases, the relevant concentrations, the rate of formation
and the trends, it is possible to diagnose the presence of an eventual malfunction:
over heating, hot spots in the core or plates, concentrations of flow, partial discharges at low
or high energy intensity, short circuits among windings, high intensity energy discharges.
Other parameters provide specific indications about the chemical-physical state of
degradation of the oil or the presence of external contaminations: presence of moisture,
particles, dissipation factor, delta tangent at 90o
C, can heavily influence the insulating
features of the oil.
The neutralization number pH, aspect and color of the oil provide indications on the level of
oxidation.
The presence of metallic elements in the oil, total and corrosive sulphur, provide evaluations
about the presence of corrosion phenomena, wear or degradation of mechanical components,
tap changer selector, and parts or the tank or accessories.
The opportunities provided by current diagnostic techniques, eventually supported by further
on-line monitoring techniques, with united operation, or off-line, tests of unit in electrical
and/or electrometrical nature requiring the de-energizing of the transformer, allow taking
informed decisions and implementing effective strategies for the management of the fleet of
equipment.
(3) Obligations of disposal
Equipment subject to inventory containing insulating liquids with a concentration of PCBs
above 0.005% by weight, when reaching the end of their operating life should be disposed of
or decontaminated. The disposal of used PCBs should be performed in compliance with local
legislation regarding the disposal of hazardous waste. The separation of PCBs from other
substances with the purpose of recovering and reusing the some PCBs is forbidden.
The mixing of PCBs with other substances or fluids is prohibited. The dilution of PCBs is
prohibited. The storage of PCBs' waste cannot be considered as disposal.
Any temporary storage and disposal of waste containing PCBs should be performed
according to local regulation as well as the Best Available Techniques (BAT). Concentration
of less than 25 ppm PCBs is considered disposable as used oil and less than 10 ppm is
approved for landfill according to Italian legislation.
(4) General diagnosis
The benefits provided by a diagnostic coverage through time, typically a 3-year program,
provide prevention of direct indirect and environmental damages, planning priorities for
maintenance interventions, repair, replacement, etc, reduction of maintenance, costs,

March 2008
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reduction of insurance, premiums, reduction of failures and loss of production, a general
improvement of efficiency and reduction of general operating cost.
(5) Inventory
The communication required by the inventory should provide the following information:
- Name or company name and address of the holder.
- Type of insulating liquids and concentration of PCBs contained by the equipment.
- Location and description of the equipment or container.
- Dates and types of decontamination/disposal done or planned.
- Quality of insulating liquids and concentration of PCBs held in containers.
The quantity of insulating liquid is the total mass of insulating liquid contained by the
equipment or container. Concentration of PCBs is the concentration by weight of PCBs
measured in the insulating liquid.
For equipment containing PCBs in concentration exceeding 50 mg/kg, 0.005%, but lower
than 500 mg/kg, 0.05%, the notification of the information reference points 1 and 2 is
sufficient.
The inventory of equipment should be made updated every two years and should be
resubmitted for updating when a change in the number of equipment or containers with
PCBs as well as the quantity and concentration of PCBs they contain, occurs.
(6) Sampling
The representative sampling of the insulating liquid is preferably taken through the lower
value, for equipment equipped with it, and through the expansion tank, conservator, for
equipment not equipped with lower value or difficult to access. In case the sampling
materials are reused, they must be properly decontaminated prior to a new sampling
operation.
(7) Visual inspection
A visual inspection is recommended to evaluate possible spills from the equipment, their
amount and the relevant counter-measures to be taken to ensure the protection of the
environment. At regular intervals PCBs containing transformers should be visually inspected.
Such inspections include: transformer identification, leakages, liquid level, driers (silica get)
state, paint stripping and corrosion, traces of dischargers in insulators, abnormal vibrations
and noise, date of inspection. In case of severe faults, leakages, tank corrosion, the
transformer should be disposed of immediately according to local regulations. The periodic
visual inspection should be annual and performed by personnel properly trained, targeted
toward the visual identification of the good operating conditions of the transformer. For
transformers up to 36 KV, the designation should be at least every 6 years for the aspect and
color of insulating liquid, the breakdown voltage at industrial frequency, the water content,
the neutralization number (acidity)and the dielectric dissipation factor (delta tangent). These
prescriptions are not always applicable for sealed transformers.

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(8) Labelling
The labelling should include the following indications: name or company of the holder of the
equipment, hazard symbols of the substance and indication of risks and caution
recommendations the label should be printed in a readable and permanent manner or material,
rigid plastic, aluminum, etc., capable of keeping unchanged the above features under the
effect of environmental agents, climate, light, dusts, etc, present on the site where the
equipment is installed.
The label should be installed an all equipment containing PCBs having a total volume
exceeding 5 dm3
/5l, and on the access door to the rooms where the equipment is located. For
equipment containing PCBs in a concentration exceeding 50 mg/kg but lower than 500mg/kg,
besides the above mentioned label, a second label reading, “Contamination by PCBs lower
than 0.05%”, should be installed. Such label should be printed in a readable and permanent
manner, as the preceding one, and can be installed separately or as an appendix to the label
previously described.
1) Labeling of decontaminated transformers
After the decontamination, transformers containing PCBs should be marked by a
permanent label, printed in high relief and indented providing a clear and readable manner
the wording:
Transformer Containing PCBs Decontaminated, as well as the following data:
The identification of the replacing fluid, in case of decontamination by treatment of the oil,
without replacing it, example by dehalogenation, indicate" same fluid dehalogenated" the
date in which the decontamination has been carried-out, the company that has performed
the decontamination, the concentration of PCBs prior to the decontamination, expressed in
percentage by weight, the concentration of PCBs at least after 50 days after the
decontamination, expressed in percentage by weight.
In case the equipment, decontaminated from PCBs, is composed of physically separated
elements, radiators, on-load tap-changers, expansion tank, etc., located in separate areas/
rooms, the label should be applied to each element of the equipment decontaminated.
(9) Reporting
During their life span, apparatus containing PCBs mush be subject to measures capable of
preventing degradation process and the spilling of PCBs, to ensure the protection of
workers, public health and the equipment. It is appropriately considered to create a file for
each equipment or a composite ensemble belonging to a single functional unit containing
PCBs. The file composes of the records of inspection, control, and current maintenance
activities carried out on the equipment and insulating liquids, included in the field of
application. The compilation of the records of maintenance activities, inventory,
inspections, sampling, test report, maintenance, decontamination, transportation, disposal,
can also be done by specific database and proper format documents for proper records.
Such operations should be carried out by qualified apparatus and expertise, properly
trained. The testing activities should be assigned to laboratories with expertise and
competence in the specific sector and operating in accordance with the best qualified
requisites.

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(10) Condition of operation and maintenance of PCBs contaminated transformers
The operation of the transformers is possible only when all the following conditions occur:
- No leakages are in progress, the presence of sweating is not considered a leakage.
- They are in good operating condition.
- They have been originally filled with insulating liquids complying with standards.
- The insulating liquid, PCBs or mineral oil contaminated by PCBs, thereby contained has
being subject to periodic checks, even on a statistical basis, and found to comply with the
applicable technical specifications relative to the dielectric quality. In particular, mineral oils
contaminated by PCBs should comply with standards. In the case of Askarel, such insulating
liquid should comply with standards. Insulating liquids not corresponding to the
classification of Askarel or mineral oil, silicon oils, esters, etc., should comply with the
requisites prescribed by the relevant applicable technical standards.
In case tests and periodic inspections of equipment containing PCBs show functional
troubles, damages, spills or degradation of the dielectric features of the insulating liquids, the
appropriate corrective actions should be implemented. The maintenance of transformers
containing PCBs may continue only if the objective is to ensure that the PCBs they contain
comply with technical standards or specifications regarding dielectric quality and provided
that the transformers are in good working order and do not leak.
The degradation process of the materials of the equipment and spillage of PCBs liquids into
the environment is estimated at about 0.1 -0.5% yearly of the average volume filling the unit.
(11) Financial Contest
Quite important is the technical analytical feature. The gathering of information is the basic
instrument for an inventory of PCBs. However, it is also true that the legislator, over the
years, has very often anticipated the analytical technical resources, leaving unavoidable
regulatory vacuums in the area of the determination of the substances under scrutiny.
Afterward, problems relative to the interventions prescribed by law are encountered,
decontamination and/or disposal. Finally, all the considerations relative to the costs of these
operations are complied adding a heavy financial burden, at low and medium term, for the
users.
These considerations shift the "environmental problem" under a more global vision of "asset
management" for which it is important to analyze deeply the technical and scientific
resources available , providing the organization of the inventory of the subjects and the
subsequent interventions , through an effective strategy, technically accurate and financially
sustainable.
The financial value of the assets typically involved by an inventory of PCBs is very high,
considering, for example, power transformers. The precise and effective discrimination of
their level of contamination or non-contamination, or the diagnosis of the level of functional
degradation and residual life are key factors in the financial management of the assets of the
fleet of equipment.
Electrical transformers represent a fundamental resource inside production, transmission and
distribution electricity systems, as well as industrial production systems. The machine down
situation of such equipment, especially grid power transformers, causes high costs for repair

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interventions and in terms of lack of income. The vision for asset management described is
then completed by a focalization on the diagnosis of the functional degradation and
evaluation of the residual life of equipment and fluids.
The implementation of systematic diagnostic inspections capable of identifying the presence
of incipient malfunctions or failures is of fundamental importance toward the reduction of
the rate of machine-down within physiological limits, as well as directing the programming
of maintenance interventions, thus minimizing operational costs.
Two alternatives should be considered to manage fluids and equipment contaminated by
PCBs, the incineration technology and the continuous mode decontamination/
dehalogenation technology, since landfilling is not a valid solution, both for the
environmental impact and the recovery of resources. The technical features and the
operational parameters of each technology, to be evaluated for environmental purposes in the
budget, are summarized as follows:-
· Efficiency and speed in eliminating the PCBs
· Investment and running costs
· Prices for disposal
· By-products generated by the treatment
· Principle of proximity
· Level of environmental compatibility
· Effects on human health
An incinerator deals only with waste, whereas a mobile decontamination unit (DMU) can
also decontaminate/dehalogenate equipment and fluids still in operation. Consequently, the
comparison cannot be made only under the point of view of elimination of the PCBs, but
must also consider the string of value associated to other factors, such as environmental
impact and social/ financial implications linked to the life cycle of transformers/equipment in
operation filled or contaminated by PCBs.
Incinerators are generally part of large fixed platforms treating several types of dangerous
waste. The investment cost for an incinerator is in the range of tens of million dollars,
whereas the cost of a DMU unit is around USD 200,000 to 250,000 per unit of treatment.
However, the financial side should not be limited to just the comparison of market prices,
since the choice of technology implies different consequences such as the functional
recovery of the equipment in one case and the replacement of assets and materials in the
other.
To create social consensus by implementing a new culture for energy and the environment
the objectives under this perspective should be:
· Protection of company assets
· Being more self-sufficient and integrated in technological processes and operational
methods
· Grab quickly all new market opportunities (Green Business) in terms of ; Creation of
mosaic of synergies for new (Green Markets) ,Generation of new jobs for young
people (Green Jobs), improve added value and profitability ( Green Money).

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23
1.5 Safety Management
In all cases of accidents national/local authorities must be notified in accordance with current
regulations. The staff properly trained to contain spills and/or performing interventions on
failed equipment must be provided with the appropriate personal safety equipment. Possible
types of accidents involving equipment and insulating liquids containing PCBs include: cold
events of low entity, such as dripping and confined spills; cold event of major entity, such as
the breaking of the tank and not confined spills with an impact on the environment; hot
events, much as fires and the formation of highly dangerous products, having an elevated
impact on the environment, such as PCDDs, 75 possible congeners, and PCDFs, 135
possible congeners originated by uncontrolled thermal oxidation reactions by PCBs.
The comparative evaluation of risks associated with PCDDs and PCDFs and the various
commercial mixtures of PCBs, Aroclor, should be carried out as a function of the relevant
equivalent toxicities, TEF with respect to 2, 3,7,8-TCDD, as pointed out by World Health
Organization (WHO).
(1) Personal protection devices
During the activities related to inspection, control, current maintenance, decontamination and
general handling of equipment and insulating liquids containing PCBs, appropriate
individual protection devices should be adopted.
The type of protection device should be chosen as a function of the risks correlated with the
activity to be performed and the risks existing on the site and/or connected with other work
operations possibly present. In case of risk of contact with contaminated insulating liquids or
surfaces, oil-proof gloves, protection glasses or screens, oil-proof overalls or aprons should
be used. During normal operations for maintenance, elimination of leakages or transfer of
insulating liquid, respiratory protection devices are not necessary, since the vapor pressure of
PCBs at ambient temperatures is very low.
Appropriate devices for respiratory protection should be used when Askarel is present, under
the following particular circumstances: possible inhalation of gases produced by electric arc;
possible contact with degradation products of Askarel in case of fire; presence of Askarel
sprayed as a result of leakage; presence of Askarel in small and confined spaces; presence of
solvents used for cleaning and washing with hydrochloric acid such as HCl.
(2) Handling and transportation
The handling of equipment containing PCBs requires the same precautions prescribed for the
handling of normal oil-filled equipment, since no risk is known for human health or the
environment, as long as the PCBs stay inside the equipment. In case the handling could
involve considerable risk of breakage of the tank /container, appropriate supplementary
measures should be implemented to prevent spilling contaminated liquids into the
environment.
The transportation of PCBs and equipment containing PCBs is designated as transportation
of hazardous goods, thus is regulated by specific rules depending upon the mode of
transportation, such as road, railway, waterways, sea or air. The international regulations are
made to prevent damages to persons, carriers, loads and the environment, regarding
appropriate packaging, labelling, characteristics of the carrier, modes of transportation,

March 2008
24
loading and unloading procedures and training of the personnel involved. On-the-road
transportation is subject to the regulation under scrutiny ,which also include exceptions when
all measures ensuring that such transportation is taking place under complete safety, and in
case of transportation of PCBs in single containers with a maximum volume of 500 ml each,
enclosed in the further outer packaging for a maximum of 2 L.
The transportation of PCBs or equipment containing PCBs finalised toward the
decontamination or disposal should be accompanied by a Waste Identifications Form, from
which the quantities, mass, origin, nature and concentration of PCBs being transported are
described. Such transportation should be carried out by subjects enrolled in the Register of
Companies Authorized to Manage Waste, for the specific category and the relevant waste
identification codes.
(3) Operation and maintenance
The maintenance of transformers containing PCBs may continue only if the objective is to
ensure that the PCBs they contain comply with technical standards or specifications
regarding dielectric quality and provided that the transformers are in good working order and
do not leak. (Council Directive 96/59/EC Article 4.3)
(4) Internal failure with breakage of the equipment / container
In case of an internal failure of an equipment containing PCBs with the breakage of the
external shell and spillage of contaminated liquid, the following precautions are
recommended:
· Do not electrically reenergise the equipment.
· Inform the management in charge of the system.
· Disconnect the equipment from the power line to put it under safe conditions.
· Implement measures capable of mitigating the spill and containing liquid spilled, in
case appropriate procedures and instruments for the interventions or adequate
know-how are not available, call qualified operators.
· Bund the zone involved and prohibits access to unauthorized personnel.
· Decontaminate the equipment / container prior to any repair intervention or disposal
in accordance with current regulation relative to waste.
· Evaluate the concentration and the extension of the possible contamination of the
environmental matrices involved, surfaces, soil, water, etc.
· Recover /decontaminate the area involved by the spill of insulating liquid and verify
the efficiency of the recovery on the environmental matrices involved, in accordance
with the applicable specific standards.
· Dispose of materials contaminated by PCBs residue of the operations for the
containment, mitigation and decontamination in accordance with the regulations
applicable for hazardous waste.

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(5) Fires
Under fire conditions, PCBs can develop highly dangerous substances for mankind and the
environment such as Dioxins and furans, Polychlorinated dibenzgodioxins (PCDDs) and
Polychlorinated dibenzofurns (PCDFs), originated by reactions from uncontrolled thermal
oxidation of PCBs. In case of accident with the burning of equipment containing PCBs, with
the breaking of the outer tank and spillage of contaminated liquid, the following precautions
are recommended:
· Leave at once and evacuate the area involved by fumes.
· Notify the event to the subjects responsible for the management of the installation and
the fire department, specifying the nature of the fire and the substances involved.
· Implement temporary measures to contain the contamination of adjacent areas, in case
appropriate procedures and equipment for the intervention or adequate know-how are
not available, call immediately qualified operators.
· Cordon-off the zone involved and prohibit access to unauthorized personnel.
· Decontaminate the equipment prior to any repair or disposal in accordance with
current legislation related to waste.
· Reclaim /decontaminate the area involved by the spill of insulating liquid and check
the effect of the reclaiming /decontamination on the environmental matrices involved,
in accordance with current regulations.
· Dispose of materials contaminated by PCBs residue of the containment, mitigation
and decontamination operations in accordance with the regulations applicable for
wastes.
(6) Actions in case of accidents
In case of an accident involving equipment and/or liquids containing PCBs, it is required that
immediate respective actions; are implemented toward the solution of the most critical
situations, to prevent the worsening of the risks, protecting the people and environmental
assets involved, avoiding delays, waste of resources and the generation of confusion or
panic.
As a function of the seriousness of the event, it is possible to identify the following logic
phases and physical actions; discovery and notification of the event to the competent
authorities, preliminary identification and diagnosis of the nature of the event and risks,
containment and mitigation of the propagation of the contamination, decontamination and/or
elimination, final evaluation and service restore.

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26
1.6 Destruction and Decontamination
“Without prejudice to their international obligations, members states shall take the necessary
measures to ensure that used PCBs are disposed of and PCBs and equipment containing
PCBs are decontaminated or disposed of as soon as possible. For the equipment and the
PCBs contained therein, which are subjected to inventory in accordance with Article 4 (1),
decontamination and/or disposal shall be effected at the latest by the end of 2010.”2
The treatment of PCBs and PCBs contaminated used insulating liquids has to be done with
proper care. Experienced and qualified personnel well aware of the health and environmental
risks associated should always perform oil treatment. Full risk assessment should always be
undertaken before commencing any treatment. Strict control should be undertaken in order to
avoid cross contamination by PCBs and to avoid accidental spills to the environment.
Pipes, pumps, and hoses should be carefully inspected for tightness. Treatments are usually
carried out with special attention to avoid emissions to the atmosphere. The decontamination
activities should utilize the Best Available Technique (BAT) to ensure through time, during
the residual life of equipment and insulating liquids, the quality of dielectric performances,
the good functional state of the equipment itself, to minimize production of waste, or spent
materials and to dispose of waste strictly according to local regulations. Also safety measures
should be taken to avoid any damage to the equipment itself. Due care should be taken when
working with hot oil. Workers should use appropriate personal protective equipment.
The treatment criteria for the definition of priorities and decontamination programs consider
the following indicators: type, dimension and total mass of the equipment, installation of the
equipment, financial value of the equipment and disposal/elimination cost, quantify of
insulating liquid and concentration of PCBs contained by the equipment, state of degradation
and critical incidence on functional efficiency, possible coincidence of the decontamination
with other maintenance interventions, and impact on the environment associated with
possible failures of the equipment and subsequent spill of contaminated liquid.
Destruction and decontamination techniques should be privileged, as fully responding to the
priority principles of safety, continuity of operation, proximity, self-sufficiency and
functional re-use. Decontaminations should be performed by operators authorized by local
authority. It is recommended that the decontaminations activities should be assigned to
operators with proven expertise and competence in the specific sector and possessing
instrumental resources and professional skills documented and correlated to the type of
process being implemented. The personnel should possess specific training and formation of
handling of hazardous substances and the control of other risks possibly present in
performance of the activity, among which the risk of electrocution.
Table 1.1 shows the outline of type of treatment methods with each advantage and
disadvantage. In the following section, some of deconstruction and decontamination
measures are introduced.
2
Council Directive 96/59/EC Article 3

March 2008
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Table 1.2 Outline of PCBs Destruction and Decontamination Processes
Process Waste Types
Accepted
Advantages Disadvantages
Incineration Oils, Residues from
Separation Processes
PCB-containing
Waste Equipment
High destruction
efficiencies achieved,
meeting legal
requirements, from any of
the range of PCBs and
waste inputs rendering
products safe.
Facilities can treat a
range of wastes, both
chlorinated and
non-chlorinated.
PCB content only as a
fuel.
Costly, especially if
wastes have to be
shipped off-site.
Incineration can attract
public opposition.
Chemical Treatment Liquid PCBs De-chlorinated oil can be
used for other purposes,
e.g. lubricating oil.
Need to establish
treatment conditions for
individual components.
Plasma Arc Systems Liquid PCBs and
Pump able Solids
Low process inventory. Limited operational
experience of plasma
systems for waste treatment.
Source: Inventory of World-wide PCB Destruction Capacity (1998) UNEP
(1) Decontamination processes
· Physical-chemical decontamination processes targeted toward the elimination of
hazardous and persistent compounds, dehalogenation.
· Change of the contaminated insulating liquids with others having the same or better
functional and environmental features.
The achievement of the objectives set by decontamination operations, to be checked after the
intervention, through diagnostic tests of the concentration of PCBs at the end of the
decontamination and after a period of at least 3 months from the re-commissioning of the
equipment, under service conditions.
The decontamination process for mineral insulating oil, can be performed both in "off-site",
an equipped site different from the location of installation of the equipment containing PCBs,
and “on-site”, at the site where they are installed. The off-site application is conditioned by
the technical and financial feasibility for a safe handling and transportation of the equipment
and liquids containing PCBs, to the decontamination installation. The later processes,
according to Best Available Techniques (BAT) can be preformed with the following
methods: refilling, in one or more cycles, selective adsorption on solid media and other
methods with the same technical and safety performances. The delivery of PCBs and
equipment containing PCBs to companies performing their decontamination in locations
different from the site of installation of the equipment should result from the identifications
form for waste and the waste input/output register in compliance with local regulations in the
area of wastes. In case of transboundary movements, the Basel Convention applies.
(2) Destruction and decontamination technologies
During the last 20 years or so, several methods for the decontamination and disposal of PCBs
and correlated compounds have been developed and implemented on an industrial scale

March 2008
28
worldwide. They include incineration, photolysis, radiolysis, dechlorination, and
bio-chemical treatment. Close-loop chemical dehalogenation is of particular interest, since it
provides the protection of equipment in operation, thus conserving high valued resources.
Until 1996, the main technical option used in Europe to dispose of PCBs was thermal
destruction and the only approved facilities were in France, UK and Finland. With the
promulgation of directive 59/96, documentation processes have been introduced in the
legislation.
The techniques on the market for handling of PCBs can be divided into four categories: land
filling, thermal treatments, designated as "destructive techniques' since it is impossible to
recover fluids and solids being treated, chemical-physical treatments, designated as 'recovery
techniques' since they provide, in most instances, a full or partial recovery of oil and
equipment, refilling or change of the initial fluid with a non-contaminated one.
There are also technologies to separate PCBs from the other parts of the transformer before
definitive disposal, thus recovering valuable materials, copper, iron, etc., and sending PCBs
to controlled disposal. The application of these processes to equipment and liquids
containing PCBs destined to disposal is conditioned, more than by technical limitations, by a
financial balance between the cost of decontamination and lower charges for final disposal,
with respect to the charges deriving from the disposal of waste as is.
The decontamination process should make systems, equipment, objects, substances and
insulating liquids containing PCBs reusable, recyclable or disposable under the best
conditions. Member States should take the necessary measures to ensure that transformers
containing more than 0.05% by weight of PCBs are decontaminated under the following
conditions: the objective of the decontamination must be to reduce the level of PCBs to less
than 0.05% by weight and, if possible, to no more than 0.005% by weight. In general, a
residual concentration of PCBs below 0.005% by weight is recommended: in fact, the
equipment decontaminated in this manner is no further subject to any decontamination
obligation, disposal, commercialization or limitation of use prescribed by local legislation.
The effectiveness of the decontamination process can be verified after at least 90 days in
service from the end of the decontamination. After such period the level of PCBs is
considered stabilized, meaning that it is possible to scientifically predict that it will not be
subject to further variations.
1) Controlled incineration: Thermal destruction processes
Incineration is a highly efficient technology for the disposal of PCBs with a considerable
impact on the environment in terms of emissions, energy requirement to provide very high
temperatures more than 1,200o
C and occupation of territory, several hectares, for logistics
and plants.
By temperatures exceeding 1,200o
C with times exceeding 2-3 seconds, a 99.9999%
decomposition can be achieved. Incineration remains the most efficient technique for the
disposal of pure PCBs waste, since it can treat all contaminated matrices in whatever
concentration, keeping always the same range of effectiveness. When the thermal
oxidation process occurs in inappropriate conditions, such as wrong value of temperatures,
detention time and turbulence during the process, there is a high probability of formation
and diffusion of very toxic substances such as polychlorinated dibenzo dioxins (PCDDs)
and polychlorinated dibenzofurans (PCDFs). It has been reported that about 0.004% of
PCBs introduced into an incinerator can be converted into PCDDs and about 0.001% into

March 2008
29
PCDFs. Thus regulations prescribe a very alternative monitoring process, resulting in
higher operating costs.
The products of full combustion include chloridic acid, carbon dioxide and steam, all
stable and non-toxic substances. One way to reduce the impact of incinerator is the
recovery of some by-products, particularly chloridic acid. This technique is implemented
by some installations. Also, as by-products, there are sludge, ashes and fumes as well as
liquids.
The by-products are classified as waste, subject to specific regulations, thus it is required
that they are made inert in order to landfill them and just in few cases they are treated for
any recovery. Modern incineration systems are equipped with sophisticated systems for
the control and destruction of micro pollutants, such as scrubbers, washing towers,
post-heating of fumes to be evacuated to prevent condensation in the chimney.
Electrical equipment must be properly pre-conditioned in appropriate installations before
being disposed. These preliminary operations include: collecting, temporary stocking,
draining and transfer of liquids containing PCBs and the preparation of the solid waste by
cutting into proper sizes, etc.
In the incineration process energy is recovered from the combustion gases, used to
pre-heat the materials to be incinerated and/or to power heat generators or power plants.
An interesting method to incinerate dangerous waste, including PCBs is also the
possibility of using cement kilns.
The main advantages are:
· Limited investments required through the use of existing installations, thus
providing a considerable saving in relation to other solutions requiring the
development of new plants. Also, the use of fluids contaminated by PCBs is a
partial substitute for normal fuel. The possibility of replacing virgin fuel with fuel
deriving from waste, resulting in savings on the energy bill and the costs of
disposal.
· The alkaline materials of the cement neutralize the acids generated during the
combustion, as the absorption of the chloridic acid, with the reduction of the risk of
corrosions, no requiring specific abatement sections.
· The solid residues of the combustion are captured by the cement and the residual
waste can be incorporated in the clinker without requiring further decontamination
treatments. Thus, no production of ashes avoids the problem of disposal of solid
residues; eventual heavy metals tend to be trapped in the product rather than being
emitted with the fumes.
· The complete destruction of PCBs thanks to elevated temperatures, from 1,370 to
1,440o
C, since the production of cement requires a high thermal capacity not
allowing sudden temperature changes in the kiln, thus sudden variations of
temperature, being the base for the formation of dioxins, are prevented.
Although it is mitigated by the recovery of energy, the environmental impact of
incineration is considerable plus the high investment and running costs have limited its
diffusion. Several problems related to are: handling, logistics, safety and monitoring and
possible accumulations created by an excess of chlorine being treated are to be considered.

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