United States
Environmental Protection
Agency
Hazardous Waste Engineering
Research Laboratory
Cincinnati OH 45268
Research and Development
EPA/600/S2-85/036 May 1985
Project Summary
Assessment of PCDDs and
PCDFs from PCB
Transformer and
Capacitor Fires
Anthony Lee
The U.S. Environmental Protection
Agency (EPA), under the Toxic Sub-
stances Control Act (TSCA), has been
mandated to develop appropriate regu-
lations for the control of exposure to
polychlorinated biphenyls (PCBs). In
light of this responsibility the EPA Office
of Toxic Substances recently Issued an
Advance Notice of Proposed Rulemak-
ing (ANPR) intended to define the
problem of releases of PCBs and other
toxic compounds during fires involving
transformers and capacitors containing
PCBs. The ANPR is intended to cover
the following areas:
• Risks associated with PCB trans-
former and capacitor fires
• Number and distribution of PCB
transformers and capacitors
• Location of equipment
• Frequency of fires
• Furan/dioxin formation
• Regulatory options
The EPA Office of Research and
Development (ORD) has also been
mandated under EPA's recently released
Dioxin Strategy document to evaluate
fire accidents involving PCB transform-
ers and capacitors as potential new
sources of polychlorinated dibenzodi-
oxins (PCODs) and polychlorinated
dibenzofurans (PCDFs) in the environ-
ment. To develop the information to
support the two mandated programs,
the EPA/ORD undertook this study to
assess the problems associated with
fires involving askarets, to catalog the
contamination experiences, and to
review potential decontamination meth-
ods as well as disposal of contaminated
material. The study recognized the
limitation of available data. It has drawn
upon the body of scientific knowledge
available on thermodynamic equilibria
of chlorinated substances and the more
common experiences gained from de-
contamination and detoxification of
PCBs in non-fire accident situations.
This study assesses the chemistry of
PCBs under thermal conditions and
evaluates the generation of PCDDs and
PCDFs. It reviews technologies for
destruction and disposal of PCBs and
their toxic contaminants. Methodolo-
gies to assess potential hazards and
reduce exposure are also discussed.
This Project Summary was developed
by EPA's Hazardous Waste Engineering
Research Laboratory. Cincinnati, OH.
to announce key findings of the research
protect that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
Polychlorinated biphenyls are a class of
compounds that have various combina-
tions of chlorine atoms attached to the
biphenyl molecule. Since commercial
introduction in the late 1920's, over 1.25
billion pounds of PCBs have been manu-
factured and used in the United States
primarily in mixtures with chlorobenzenes
known as askarels, which are used as
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dielectric fluids for electrical transformers
and capacitors, heat transfer systems,
and hydraulic systems.
Federal regulation of PCBs took sev-
eral years to develop. Beginning in the
late 1960's, scientific evidence began to
accumulate on PCBs'various toxic effects
and concentration in many biological
species. Because of these concerns, in
1971, the Monsanto Industrial Chemical
Co., the sole United States producer,
terminated sales of PCBs for all but closed
electrical systems uses. In 1976, Con-
gress enacted the Toxic Substances Con-
trol Act and included special provisions
for the regulation of PCBs. Accordingly, in
1979, EPA banned all production and
sales of PCBs. Additional regulations
enacted under TSCA now govern the
disposal of PCBs and equipment contain-
ing PCBs. A large amount of the PCBs
sold in the United States prior to the ban
is still in use as dielectric fluid in trans-
formers and capacitors.
Recently, there have been additional
concerns brought on by the finding of
toxic contaminants in PCBs and askarel
fluids including PCDFs, chlorinated ben-
zenes and other chlorinated substances.
PCDFs and other chlorinated substances
are formed as contaminants in the manu-
facturing and formulation processes for
PCBs and askarel fluids. PCDDs can be
formed from the reaction of chlorinated
benzenes when askarel fluids are heated
to high temperatures. The finding of
PCDFs and the potential generation of
PCDDs under thermal conditions has
major implications for the recently-
adopted EPA strategy for mitigating and
controlling chlorinated dioxins in the
nation's environment. Findings of such
toxic chemicals will also complicate
emergency response and clean-up pro-
cedures for fires involving transformers
and capacitors containing PCBs.
Several such fires have been reported.
The most famous fire involved a trans-
former and occurred in an 18-story office
building in Binghamton, New York on
February 5, 1981. Similar cases have
been reported in other parts of the country
and in foreign countries such as Sweden
and Finland. These accidents have led to
the need for assessing potential envi-
ronmental loading of PCDDs and PCDFs
and human exposure risk from this new
source category. Additionally, because
such fire accidents have occurred ran-
domly in office buildings, schools, etc.,
and not only in industrial plants, there is a
high public awareness of this issue. Thus,
there is a genuine public concern over
potential exposure to highly toxic sub-
stances (i.e., dioxins and furans) from
such fire accidents.
Fire fighters, electric utility companies
and insurance companies are particularly
concerned that fire emergency proce-
dures and fire site clean-up protocols may
not be adequate in light of these new
findings. Present fire fighting methods
were developed when the hazards of
exposure to highly toxic chemicals were
not as well understood. In an already
dangerous profession, fire fighting per-
sonnel must now recognize the danger of
exposure to hazardous chemicals with
potential long-term health implications.
Conclusions
Approximately 130,000 transformers
and 2.8 million capacitors currently in
service contain PCBs or mixtures of PCBs
and trichlorobenzenes which are also
called askarels. Approximately 2 million
mineral oil transformers have fluid con-
taminated with PCBs in concentrations of
500 parts per million or greater.
The transformer involved in a fire in
Binghamton, New York contained a mix-
ture of 65% Aroclor 1254 and 35%
chlorinated benzenes together with some
other additives. Analyses of soot samples
taken from the building showed high
levels of PCBs, and the presence of
2,3,7,8-tetrachlorodibenzodioxin (2,3,7,
8-TCDD) and 2,3,7,8-tetrachlorodibenzo-
furan (2,3,7,8-TCDF). The estimated
cleanup costforthe building is $24 million
and almost $1 billion in liability claims are
pending against the state in law suits
filed primarily by the fire fighters.
Laboratory combustion studies on PCBs
and askarels have identified a variety of
other chlorinated products such as poly-
chlorinated naphthalenes, pyrenes, bi-
phenylenes and chrysenes. The types of
chlorinated products that are formed
depend on the composition of the fluid in
the transformer or capacitor. In the
Binghamton incident, both PCDDs and
PCDFs were identified whereas after the
San Francisco fire, only PCDFs were
found. The Binghamton transformer con-
tained a mixture of PCBs and trichloro-
benzenes and the San Francisco trans-
former contained only PCBs. The finding
of PCDDs in the Binghamton incident is
attributed to chemical reactions involving
trichlorobenzenes present in the trans-
former fluid.
The presence of highly toxic substances
such as PCDFs and PCDDs in PCBs fire
incidents has increased concerns for the
safety of emergency response personnel
and has complicated cleanup and reme- |
dial measures. There is a need for devel- *
opment of a generally accepted protocol
for fighting and extinguishing fires in-
volving PCB electrical equipment.
Electrical utilities can assist local fire
fighting departments with better informa-
tion on the problems associated with PCB
fires. Fire departments should know the
number and location of PCB transformers
and capacitors within their jurisdictions.
Highly visible labels or signs should be
placed on all PCBs-containing electrical
equipment and in other nearby areas to
indicate the presence of these devices.
Electrical utilities, owners and/or opera-
tors of the equipment should retrofit the
equipment to assurethat electrical power
could be rapidly disconnected in the event
the transformer enters a failure mode.
The primary load breaker air switch on
the high-voltage side of the transformer
should be located outside the equipment
vault to allow rapid disconnect without
entering a vault potentially containing
high concentrations of PCBs and associ-
ated pyrolysis products.
Response operations during the initial
phase of a fire incident involving trans-
formers and capacitors containing PCBs
requires familiarity with response orga-
nization and management, the uses and A
limits of equipment and apparatus, site *
entry, control, and decontamination pro-
cedures. In order to control PCB fire
situations, adequate protective clothing,
equipment and fire extinguishing chemi-
cals are necessary to ensure personnel
safety.
PCB transformer/capacitor fires are
unique because of the toxic residues
generated and the resultant long-lasting
contamination. Every effort should be
made to put out the fire as quickly as
possible in order to minimize the produc-
tion of highly toxic pyrolysis products.
After the fire, access to areas possibly
contaminated by the fire must be limited
until the extent of contamination can be
determined. Wipe and bulk soot sampling
are used to identify areas contaminated
with PCBs and to delineate the extent of
both vertical and horizontal contamina-
tion.
There are no Federal guidelines to
define acceptable cleanup levels for PCBs
releases due to fires. NIOSH has found
background levels up to 0.5 meg PCBs per
100 cm2 of surface area in urban areas. In
the absence of certain PCDF and PCDD
isomers, the mitigation effort could be
directed at cleanup of the PCBs contami-
nation to 0.5 meg/100 cm2 of affected
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area. In terms of airborne exposure, the
NIOSH recommended guideline for the
workplace is 1.0 meg PCBs per cubic
meter of air.
The presence of PCDF and PCDD
isomers will affect surface and air cleanup
guidelines according to the biological and
toxicological activity of the specific iso-
mers. Reoccupancy criteria have been
established by the State of New York and
the State of California following the
Binghamton and the San Francisco fires.
The State of New York proposed an
allowable daily intake of 2 pg/kg/d for
2,3,7,8-TCDD, resulting in an air/inhala-
tion exposure limit of 10 pg/m3 for
2,3,7,8-TCDD. A limit of 39 pg/m3 for
2,3,7,8-TCDF was proposed. The State of
California proposed air exposure guide-
lines of 10 pg/m3 for 2,3,7,8-PCDDs/
PCDFs and 1.0 mcg/m3 for PCBs. The
criteria for surface exposure are 3 ng/m2
for 2,3,7,8-PCDDs/PCDFs and 100
mcg/m2 for PCBs. In addition to these
values for decontaminated areas outside
of the transformer vault, the State of
California proposed reentry guidelines for
the area inside the vault. These consist of
an air exposure of 80 pg/m3 for 2,3,7,8-
PCDDs/PCDFs and 1.0 mcg/m3 for PCBs
and a surface exposure of 24 ng/m2 for
2,3,7,8-PCDDs/PCDFs and 1.0 mg/m2
for PCBs. Sweden and Finland have also
established reoccupancy criteria after the
occurrence of PCBs fire incidents.
Anthony Lee is with Technical Resources. Inc., Rockville, MD 20852.
Brian A. Wastfall is the EPA Project Officer fsee below).
The complete report, entitled "Assessment of PCDDs and PCDFs from PCB
Transformer and Capacitor Fires," (Order No. PB85-188 837/AS; Cost: $14.50,
subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Hazardous Waste Engineering Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
U.S. GOVERNMENT PRINTING OFFICE: 1985-559O16/27055
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