United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/SR-95/120 August 1995
&EPA Project Summary
Demonstration of Alternative
Cleaning Systems
Dean M. Menke, Gary A. Davis, Lori E. Kincaid, and Rupy Sawhney
This report represents the first dem-
onstration of cleaner technologies to
support the goals of the 33/50 Program
under the EPA Cooperative Agreement
No. CR821848. It focuses on substi-
tutes for solvent degreasing processes
that eliminate the use of chlorinated
organic solvents. The substitute tech-
nologies were 1) an aqueous wash sys-
tem; 2) a no-clean technology; and 3) a
hot water wash system. Technical, en-
vironmental, and economic evaluations
were performed to determine the mer-
its of the substitutes as they were
implemented by Calsonic Manufactur-
ing Corporation, the project's industry
partner. A national environmental im-
pact evaluation was also performed to
estimate the potential impacts on the
nation's environment if entire indus-
trial sectors were to implement the sub-
stitutes.
The demonstration strongly supports
the implementation of the alternative
technologies. The implementation of the
cleaning process alternatives either
improved or did not affect the perfor-
mance of subsequent process steps or
the quality of the products. The aque-
ous wash system reduced cleaning
cycle times by 50% and part reject rates
by nearly 77% with improved cleaning
characteristics. The no-clean alterna-
tive had no effect on either production
or part reject rates. The substitutes sig-
nificantly reduced the quantity of toxic
chemicals used and released. The tra-
ditional processes released 1,1,1-
trichloroethane (TCA) to the air, as well
as generated a TCA hazardous waste
stream; the substitutes generate either
a non-hazardous wastewater discharge
(aqueous and hot water wash systems),
or a volatile organic compound air
emission (no-clean technologies). Each
alternative offered significant financial
advantages as compared to the tradi-
tional solvent degreasing systems when
the economics were evaluated using
activity-based cost accounting.
The national environmental impact
evaluation compared the life-cycle en-
vironmental impacts of traditional chlo-
rinated solvent systems to the
alternatives. The evaluation suggests
that significant reductions in life-cycle
chemical emissions will occur with the
implementation of alternative cleaning
systems. Generally, for the aqueous
wash systems, the shift would mean
increased wastewater loads and oily
pollutant discharges to POTWs. The
nation's POTW infrastructure, in aggre-
gate, can handle these increased loads.
The shift in waste stream composition,
however, must be evaluated on a case-
by-case basis.
This Project Summary was developed
by EPA's National Risk Management
Research Laboratory, Cincinnati, OH to
announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
The "Cleaner Technology Demonstra-
tions for the 33/50 Chemicals" project is a
cooperative agreement between the U.S.
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Environmental Protection Agency (EPA),
National Risk Management Research
Laboratory (NRMRL, formerly Risk Re-
duction Engineering Laboratory) and the
Center for Clean Products and Clean Tech-
nologies (Center) of The University of Ten-
nessee. The research of this project
supports the voluntary pollution preven-
tion initiatives of the 33/50 Program, while
having applications within a broad range
of industries. This report represents the
first demonstration project to be completed
under the EPA NRMRL project.
Objectives
The overall objective of this project was
to evaluate substitutes for the 33/50 chemi-
cals in order to encourage reductions in
their use and release. This report focuses
on substitutes for solvent degreasing pro-
cesses that eliminate the use of the 33/50
chlorinated organic chemicals. In this study
the Center worked directly with an indus-
try partner, Calsonic Manufacturing Cor-
poration (CMC) of Shelbyville, TN, to
demonstrate substitute feasibility.
To meet the project objective, technical,
environmental, and economic evaluations
of solvent degreasing substitutes were
evaluated. A fourth evaluation, a national
environmental impact evaluation, was per-
formed to estimate the impacts to the
nation's environment if entire industrial
sectors were to implement similar alterna-
tives to solvent degreasing. Within each
evaluation, the following objectives were
established:
1. Technical Evaluation
• evaluate the effect of a substitute
on process and product perfor-
mance as compared to the 33/50
chemicals
2. Environmental Evaluation
• evaluate the potential for reduction
in releases and off-site transfers of
the 33/50 chemicals in the produc-
tion process or product stage
• compare the overall life-cycle en-
vironmental attributes of the substi-
tute as compared to the 33/50
chemicals
3. Economic Evaluation
• evaluate the total cost of the sub-
stitute as compared to the 33/50
chemicals
4. National Impact Evaluation
• evaluate the national environmen-
tal impact of replacing the 33/50
chemicals with the substitute
Methodology
Data required to perform the technical,
environmental, and economic evaluations
were collected through data request tables,
site visits, and interviews with CMC em-
ployees. Data request tables, completed
by CMC and during site visits, allowed for
the collection of process information in-
cluding capital costs, operating and main-
tenance costs, utilities consumption, and
production data. Similar data were re-
quested for both the solvent degreasing
systems (historic data) and alternative sys-
tems (current data). Questions concern-
ing generation rates and disposal costs of
waste (hazardous and non-hazardous) and
waste water accompanied the data re-
quest tables, as well as questions con-
cerning permitting requirements and costs.
These questions were also directed at op-
erations both before and after the process
changes.
Site visits and interviews allowed Cen-
ter staff to become familiar with the op-
erations of CMC, ask specific questions to
complete and clarify the data request
tables, and to maintain a working contact
with CMC. An extended site visit near the
completion of this project was conducted
to observe the day-to-day operations of
the process lines under investigation in
order to extend the traditional economic
evaluation by using activity-based cost
accounting.
The national impact evaluation utilized
the knowledge of CMC's process changes
to identify and evaluate potential changes
on a national scale if entire industrial sec-
tors were to implement similar solvent
degreasing alternatives, to CMC's. Toxic
Release Inventory (TRI) data and infor-
mation from various literature sources were
used to develop a life-cycle evaluation of
chlorinated solvent degreasing and its al-
ternatives.
CMC'S Chlorinated Solvent
Substitutes Program
CMC is located in Shelbyville, TN, with
several sister companies throughout the
U.S. and the world. CMC employs ap-
proximately 800 persons, and has more
than 430,00 ft2 of manufacturing area di-
vided between two sites, three buildings.
CMC manufactures automotive parts, in-
cluding heaters, blowers, cooling units,
motor fans, radiators, auxiliary oil coolers
and exhaust systems.
To meet internal protocols to eliminate
1,1,1-trichloroethane (TCA) from its manu-
facturing processes, CMC initiated a num-
ber of changes to eliminate solvent
degreasing applications. These changes
included an aqueous wash system, a no-
clean process which employs an evapora-
tive lubricant to eliminate the need for
solvent degreasing, and the application of
a hot water wash to remove forming oils.
Technical, environmental, and economic
evaluations were performed for the aque-
ous wash and no-clean alternatives to de-
termine their merits. The merits of the hot
water wash system were presented as
supplemental information to the aqueous
wash alternative. An introduction to these
process changes, and the manufacturing
lines which utilize them, is presented be-
low.
The Radiator Line and Aqueous
Wash System
Radiators are designed to hold a large
volume of water and antifreeze in proxim-
ity to a large volume of air to allow effi-
cient heat transfer from the fluid to the air.
CMC manufactures the tube-and-fin type
of radiator core, consisting of a series of
long tubes extending between a top tank
and bottom tank of the radiator. In this
type of configuration, fins are placed be-
tween the tubes; air passes between the
fins and around the outside of the tubes,
absorbing heat from the fluid in the tubes.
CMC manufactures the tubes and fins
of the radiator core from aluminum stock.
Tubes are formed from aluminum rolls at
a tube-forming station with the assistance
of a forming/cooling fluid, cut to length,
and sent to assembly. To form the fins,
rolls of aluminum are lubricated with a
forming (napthenic) oil, fed through fin
corrugators, cut to length, and sent to
assembly. The tubes, fins, and prefabri-
cated endplates are assembled in a jig to
complete the radiator core.
Following assembly, the cores are
cleaned by a conveyor aqueous wash sys-
tem to remove the forming oils, cutting
oils, coolant, and other soils. The aque-
ous wash process begins with a water
wash, intended to remove the majority of
the contaminants, followed by a heated
detergent bath, and completed by a hot
water rinse. Effluent from the aqueous
wash process is sent to a wastewater
treatment plant at the facility for pretreat-
ment prior to discharge to the local sewer
system. After the aqueous wash, the ra-
diator cores continue on the conveyor for
flux application, drying, and brazing. Final
assembly includes nylon fluid tanks and
leak testing.
The current aqueous wash system was
adapted in 1991. Previously, five batch
vapor degreasers were used to clean the
assembled radiator core, one located at
each fin corrugation and assembly sta-
tion. Under this scheme the radiator core
was an assembly of corrugated fins (pro-
cess above) and prefabricated tubes and
endplates supplied by another company.
These assemblies were then cleaned in
one of the five vapor degreasers, using
1,1,1-trichloroethane as the degreasing
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solvent. The use of TCA resulted in re-
leases of TCA to the air from the process,
releases to water (wastewater) from sol-
vent carry over on parts to subsequent
process units, and a hazardous waste
stream of spent TCA. CMC sent this haz-
ardous waste stream to an off-site recy-
cling facility. To eliminate these waste
streams and improve the cleaning pro-
cess, CMC implemented the aqueous
wash system.
The Condenser Line and No-
Clean Technology
CMC manufactures condensers for use
in automobile air conditioning systems. The
condenser consists of a serpentine tube
on which fins have been mounted. Com-
pressed vapor passes through the tube;
air passing around the fins and between
the tubes removes heat from the com-
pressed vapor. The cooled vapor con-
denses and runs into a receiver-dryer.
CMC manufactures the fins from rolls of
aluminum, and bends and cuts the tubes
from rolled aluminum-tube stock.
In 1993 CMC converted its fin manufac-
turing process from a conveyor solvent
degreasing process using TCA to an
"evaporative" oil, no-clean process. In this
no-clean system, rolls of aluminum are
lubricated with a low-boiling-point oil and
fed through a fin corrugator. The fin then
passes through fin driers to evaporate the
oils. CMC operates four fin corrugator sta-
tions in the condenser line. In the current
system the corrugated fin is conveyed
through the now empty vapor degreasing
chambers, then cut to length and sent to
assembly.
The Converter Line and Hot
Water Wash System
Catalytic converters are automobile ex-
haust units which consist of a ceramic
substrate and wire mesh encased in a
metal shell. CMC assembles converters
from shells, flanges, ceramic substrates,
and wire mesh separators supplied by
other manufacturers. After receiving these
materials, CMC cleans the metal shell
halves and flanges in a conveyor hot wa-
ter wash system to remove cutting and
lubricating oils left by the manufacturer.
The wash system consists of a hot water
spray zone, followed by a second hot wa-
ter spray (rinse) zone and a drying oven.
After cleaning, the ceramic substrate and
wire mesh separator are inserted in the
two shell halves, which are then welded
together with the flanges, to form the con-
verter unit. Each catalytic converter is leak-
tested using an air-based pressure-decay
system. The converters then continue
along the process train to be incorporated
into the exhaust system.
Until December 1993, CMC used a con-
veyor vapor degreaser with TCA as the
degreasing solvent. The current equipment
used in the hot water wash system was
converted by CMC from an obsolete muf-
fler washing system and a defunct paint
spray booth and curing oven.
Results of the Technical,
Environmental, and Economic
Evaluations
Over the last four years CMC has imple-
mented a number of changes to eliminate
TCA from its cleaning processes. Efforts
to accomplish this goal included the in-
stallation of an aqueous wash system (de-
tergent) which replaced five solvent
degreasers on a radiator manufacturing
line, the replacement of a petroleum-based
lubricant with an evaporative lubricant that
does not require cleaning for subsequent
processing on a condenser manufacturing
line, and the installation of a hot water
wash system to replace a solvent
degreaser on a catalytic converter manu-
facturing line. These changes, along with
similar changes on other process lines,
eliminated the use of TCA as a cleaning
solvent within CMC's manufacturing facil-
ity. Total elimination of TCA from cleaning
processes was accomplished by Novem-
ber, 1994.
The technical, environmental, and eco-
nomic evaluations performed in this study
were completed using CMC's historic
records, information obtained from site vis-
its and interviews with CMC employees,
the on-line TRI data base, and literature
searches. The radiator and condenser
manufacturing lines were the main focus
of the research. The merits of the hot
water wash system were presented as
supplemental information to the aqueous
wash alternative. The environmental analy-
sis of CMC was expanded to evaluate the
national environmental impacts if entire
industry sectors were to implement similar
process changes.
Technical Evaluation
The technical evaluation analyzed the
merits of the alternative cleaning systems
(both the aqueous wash and the no-clean,
evaporative lubricant systems) by com-
paring the rates of production (i.e., cycle
time required to clean one part) and the
part reject rates between the old and new
processes. Both historic data and inter-
views with CMC quality control staff es-
tablished the results shown in Table 1.
A significant decrease in cycle time was
experienced with the implementation of
the aqueous wash system in the radiator
line; cycle time to clean one radiator unit
was decreased by 50%. The process
bottleneck, which was the solvent
degreasing application, has now shifted
away from the cleaning operation, and
employee attentions can be focused upon
other operations to further optimize the
manufacturing process.
A significant decrease in the parts re-
ject rate for the radiator line was also
experienced after the implementation of
the aqueous wash system. This decrease,
over 76%, is predominantly attributed to
the improved cleaning characteristics of
the aqueous wash system. The produc-
tion and part reject rates for the condenser
line, though not statistically evaluated due
to data limitations, were evaluated through
employee interviews. These interviews
established that the implementation of the
no-clean process alternative had little ef-
fect on either rate.
Environmental Evaluation
The changes in chemical releases and
transfers to the environment from CMC's
manufacturing facilities due to the imple-
mentation of the alternative processes in-
cluded the following:
1. elimination of TRI reporting require-
ments of TCA hazardous waste
emissions, from each process line;
2. the creation of a state-regulated
VOC air emission for the condenser
line; and
3. the creation of a waste water stream
for the radiator line.
These changes are summarized for the
radiator and condenser manufacturing lines
in the following table (Table 2). It is as-
sumed that air releases and hazardous
waste transfers are the only TCA emis-
sions from CMC processes. Therefore,
Table 1. Summary of the Technical Evaluation Results
Line
Cycle Time
Part Reject Rate
Radiator 50% decrease was experi-
enced after aqueous wash
implementation
Condenser no significant change
76% reduction in part reject rate due
to aqueous wash system
no significant change
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Table 2. Summary of Environmental Evaluation Results
Line
Total Waste Generation per Year
Solvent Degreasing Operations
Alternative Systems Operations
Radiator
171, 500 Ib
114,900 Ib
56,600 Ib
TCA consumed
TCA haz. waste transfers
TCA air releases
(1990)
22,1 00 Ib
2.0 million gal
1 0,800 Ib
64,780 Ib
detergent consumed
wastewater generated
non-haz., oily waste transfers
non-haz. wastewater treatment solids transfers
(1992)
Condenser
121, 500 Ib
14,400lb
1 '5,400 Ib
46, 100 Ib
(1992)
TCA consumed
petroleum lub. consumed
TCA haz. waste transfers
TCA air releases
1 2,200 Ib
1 2,200 Ib
evap. lub. consumed
VOC air releases
(1994)
based on TCA consumption rates and line-
specific hazardous waste generation esti-
mates, the air releases were estimated.
Other line-specific information was drawn
directly from purchasing records.
Though eliminating the use and hazard-
ous waste disposal of TCA, the hot water
wash system of the converter line was not
quantitatively evaluated in this analysis.
However, a qualitative evaluation of this
system is presented throughout the evalu-
ations of the report.
Though the aqueous wash system of
the radiator line generates two million gal-
lons of wastewater per year, overall chemi-
cal consumption, when compared to the
solvent degreasing system, has greatly
decreased. The consumption rate of 2,640
gal/yr of detergent is minimal when com-
pared to the 15,840 gal/yr (171,700 Ib/yr)
of TCA previously consumed. The evapo-
rative lubricant system of the condenser
line has similar advantages; the release
of 12,200 Ib/yr of VOC-lubricant is an or-
der of magnitude less than the 121,500
Ib/yr of TCA released by the degreasers.
These data clearly show the trade-off
issues that must be considered when
choosing between alternative cleaning sys-
tems. For the radiator line, releases of the
toxic, ozone-depleting chemical TCA were
eliminated, but a larger volume, low-toxic-
ity wastewater stream was generated. Al-
though hazardous waste management
requirements have been eliminated for this
line, permitted discharge requirements set
by the local publicly owned treatment
works (POTW) must still be met. For the
condenser line, hazardous waste and TCA
were once again eliminated. Air releases
decreased substantially, suggesting less
potential employee exposure; complete
data on the relative toxicity of TCA and
the mineral-spirit-based VOCs emitted by
the evaporative lube, however, are not
available. This is one of the reasons CMC
is now switching to a non-petroleum based
evaporative lube.
Economic Evaluation
Two economic evaluations were com-
pleted for the analyses of the alternatives.
The first evaluation used a traditional
method focusing on direct costs. The sec-
ond method utilized activity-based costing
to more accurately allocate overhead costs
to the appropriate products and processes.
Finally, a hybrid of these methods was
used to more accurately represent the
costs and benefits of the alternatives.
Tables 3 and 4 summarize the results of
traditional and hybrid economic analyses
for the radiator and condenser manufac-
turing lines, respectively.
Table 3 shows that the hybrid method
identified additional direct costs associ-
ated with the solvent degreasing units of
the radiator line that would have been
part of an overhead cost factor in a more
traditional analysis. These results illustrate
very clearly that traditional cost analyses
are not adequate to fully estimate the ben-
efits of pollution prevention projects. By
properly allocating through ABC that would
normally be part of an overhead factor,
this study demonstrates the costs-benefits
of the aqueous wash system, benefits be-
yond traditional costing techniques are re-
alized.
The results of the economic analysis for
the condenser line did not change the
final conclusions since the evaporative lube
system had clear advantages even with
traditional cost methods. By using the hy-
brid approach, however, the cost savings
due to the implementation of this alterna-
tive were even greater.
National Environmental Impact
Evaluation
The environmental evaluation of CMC's
process changes was used to estimate
the potential environmental impacts of the
alternatives to solvent degreasing if entire
industrial sectors were to implement simi-
lar changes. This evaluation utilized the
life-cycle concept to evaluate the potential
environmental impacts which could result
throughout the life cycle of the chemicals
used in the traditional and alternative pro-
cesses. The elimination of chlorinated sol-
vents from materials and parts degreasing
could significantly impact the national emis-
sions of these chemicals from their produc-
tion, use and disposal. The implementation
of the alternative systems, though having
associated releases and transfers of other
chemicals, could significantly decrease the
environmental impacts now associated with
the life cycle of solvent degreasers and
the solvents used.
Replacing chlorinated solvent degreas-
ers could substantially reduce the use of
approximately 499.9 million Ib of chlori-
nated chemicals in materials and parts
degreasing applications. In addition to the
direct use and disposal emissions that
would be reduced, an estimated 460,000
Ib of solvent emissions from production
facilities could also be reduced. This
460,000 Ib estimate is based on the quan-
tity of the chlorinated solvents currently
produced, the emissions from these pro-
duction processes, and the distribution of
the chemicals to solvent degreasing appli-
cations.
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Table 3. Comparison of Hybrid and Traditonal Analyses-Radiator Manufacturing Line
Hybrid Analysis
Tradition, Direct Cost Analysis
Analysis
Solvent System
Aqueous Wash System
Solvent System
Aqueous Wash System
Payback
NPV (5-yr)
NPV (10-yr)
NPV (15-yr)
$2,584,150
$5,725,530
$9,547,510
2.4 yr
$1,514,260
$3,073,640
$4,762,870
$660,580
$1,464,270
$2,442,090
11.6yr
$808,280
$1,508,720
$2,147,930
Notes: 1. i = interest rate/period = 4%.
2. the capital investment of the aqueous wash system was depreciated (straight-line) over seven yr.
3. assumptions: inflation rate of zero and equal costs/yr.
4. dollar values represent costs.
Table 4. Comparison of Hybrid and Traditional Analyses-Condenser Manufacturing Line
Hybrid Analysis
Tradition, Direct Cost Analysis
Analysis
Solvent System
Evaporative Oil System
Solvent System
Evaporative Oil System
Payback
NPV (5-yr)
$1,089,550
0.27 yr
$219,660
$619,750
0.45 yr
$99,930
Notes: 1. i = interest rate/period = 4%.
2. the capital investment of the aqueous wash system was depreciated (straight-line) over 7 yr.
3. assumptions: inflation rate of zero and equal costs/yr.
4. dollar values represent costs.
The implementation of an aqueous wash
alternative has unique emissions of its
own. Detergents, a mixture of surfactants,
builders, chelators, and other ingredients,
have associated chemical production re-
leases and transfers. Emissions from pro-
duction of commonly used ingredients
(e.g., ethoxylated alcohols, alkylbenzene
sulfonates, EDTA, and tetrapotassium py-
rophosphate) include ethylene, ethylene
glycol, benzene, glycol ether, and a vari-
ety of acids. An estimate of the quantity of
detergent ingredients applied to industrial
applications was not available, and there-
fore an estimate of the production releases
which could be allocated to the industrial
use of detergents was not possible. How-
ever, order-of-magnitude calculations show
that life-cycle releases and transfers could
be significantly reduced with the imple-
mentation of the aqueous alternative.
A second issue to address when con-
sidering the life-cycle attributes of aque-
ous wash systems is the proper
management of the water waste stream.
Pretreatment of the wastewater from aque-
ous systems may be required to ad-
equately remove oils, greases, biological
oxygen demand (BOD), and suspended
solids. The conclusions from the national
environmental impact evaluation indicated
that the infrastructure of wastewater treat-
ment facilities is sufficient to handle the
increased wastewater flow and load if en-
tire industry sectors shifted from solvent
to aqueous systems.
Conclusions
The demonstration strongly supports the
implementation of the alternative technolo-
gies. The implementation of the cleaning
process alternatives either improved or
did not affect the performance of subse-
quent process steps or the quality of the
products. The aqueous wash system re-
duced cleaning cycle times by 50% and
part reject rates by nearly 77% with im-
proved cleaning characteristics. The no-
clean alternative had no effect on either
production or part reject rates. The substi-
tutes significantly reduced the quantity of
toxic chemicals used and released. The
traditional processes released 1,1,1-
trichloroethane (TCA) to the air, as well
as generating a TCA hazardous waste
stream; the substitutes generate either a
non-hazardous wastewater discharge
(aqueous and hot water wash systems),
or a volatile organic compound air emis-
sion that is much less no-clean technol-
ogy. Each alternative offered significant
financial advantages as compared to the
traditional solvent degreasing systems
when using activity-based cost account-
ing and compared to the traditional sol-
vent degreasing systems.
The national environmental impact
evaluation compared the life-cycle envi-
ronmental impacts of traditional chlorinated
solvent systems versus the alternatives.
The evaluation suggests that significant
reductions in life-cycle chemical emissions
will occur with implementation of alterna-
tive cleaning systems. Generally, for the
aqueous wash systems, the shift would
mean increased wastewater loads and oily
pollutant discharges to POTWs. The
nation's POTW infrastructure, in aggre-
gate, can handle these increased loads,
however, the shift in waste stream com-
position must be evaluated on a case-by-
case basis.
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Dean M. Menke, Gary A. Davis, Lori E. Kincaid, and Rupy Sawhney are with
the University of Tennessee, Knoxville, TN 37996-0710
Diana R. Kirk is the EPA Project Officer (see below).
The complete report, entitled "Demonstration of Alternative Cleaning Systems,1
(Order No. PB95-255741; Cost: $27.00, 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:
National Risk Management Research Laboratory
U. S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection Agency
Technology Transfer and Support Division (CERI)
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/SR-95/120
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