EPA 560/6-76-007
DEVELOPMENT OF A STUDY PLAN FOR DEFINITION
OF PCBS USAGE, WASTES, AND POTENTIAL
SUBSTITUTION IN THE INVESTMESNT
CASTING INDUSTRY
TASK III
JANUARY 1976
FINAL REPORT
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF TOXIC SUBSTANCES
WASHINGTON, D.C. 20460
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EPA 560/6-76-007
DEVELOPMENT OF A STUDY PLAN FOR DEFINITION OF PCBS
USAGE, WASTES, AND POTENTIAL SUBSTITUTION IN
THE INVESTMENT CASTING INDUSTRY
Task III
EPA Contract No. 68-01-3259
EPA Project Officer:
Thomas Kopp
For
Environmental Protection Agency
Office of Toxic Substances
4th and M Streets, S.W.
Washington, D.C. 20460
January 1976
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REVIEW NOTICE
This rerort has been reviewed by the Office of Toxic Substances, EPA
and approved for publication. Approval does not signify that the contents
necessarily reflect the vieNS and rolicies of the Environmental Protection
Agency, nor does nention of trade nanes or cOITU1'ercial products constitute
endorsenent or recommendation for use.
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TABIE OF OONTENTS
1.0
S~~J{ . . . . . . . . . . . . .
. . . .
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2.0
INTRODUCTION"
. . . . "
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2.1 Purpose and Objectives of Task III . . . . .
2.2 Sumna:ry of Work to Date on Invesbrent Casting
Under Task I of Contract No. 68-01-3259 . . . . .
2.3 Use of Polychlorinated Terphenyls in
Invesbrent Casting. . . . . . . . . . .
. . . . .
3. 0 CURRENT KNOt7LEDGE OF THE INVES'IMENT CASTING INDUSTRY. .
3.1 General Background. . . . . . . . . . . . . . . .
3.2 Principles of Invesbrent Casting. . . . . . . . .
3.3 Foundry Process-Use of PCT and PCB Filled Waxes. .
4.0 OUTLINE OF STUDJ{ PLAN . . . . . . . . . .
. . . .
4. 1 Characterization of Industry Scope. . . . . . . .
4.2 Process Characterization . . . . . . . . . .
4.3 ~ternative Technology. . . . . . . . . . . . . .
4.4 Environmental and Human Health Effects. . . . . .
5. 0 DETAILED DISCUSSION OF THE INDUSTRY STUDJ{ PIAN
. . . .
5.1 Objectives of the Plan. . . .
5.2 Material Balance. . . . . . .
. . . .
. . . . . .
. . . .
5.3 Wax Manufacturing. . . . . . . . . . . . . . . .
5.4 Summary of Results from IC Industry Study Plan. .
5.5 Role of Section 308 Authority in Study Plan
6. 0 DISCUSSION OF ALTERNATIVES STUDJ{
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"
7.0 DISCUSSION OF ENVIIDNMENTAL QUALIT]{ AND
HUMAN HEALTH EFFECTS PORTION OF STUDJ{ .
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8.0 REFERENCES. . . . . . . . . . . . . .
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1.0
SUMMARY
This report sUImB.nzes the current knowledge of decachlorobiphenyl
(deka) and polyc.hlorinated terphenyls (pcrs) as wax fillers in the investm2nt
casting industry; this knowledge is used to develop a detailed study plan of
the industry. Significant information gathering efforts would be required
to establish a complete picture of the practices, processes, and products of
this industry, which, in this instance, is taken to include casting wax manu-
facture as well as wax usage in fOlmdries. Definition of the waste streams
and emissions from the processes used will require sampling and analysis
efforts in addition to the gathering of available process data from the in-
dus try .
An approach to determining the most sui table al ternati ves to deca-
chlorobiphenyl and pcrs is presented; filler substitutes and the use of un-
filled waxes are the hvo general alternatives to be studied. At present there
appear to be no technical barriers to discontinuation of deka and pcrs as
fillers, although use of al ternati ves may increase product cost on the order
of 10 percent. In determining the most promising alternatives, product and
process oriented technical factors must be evaluated, but potential environ-
rrental and hwnan health effects may prove to be the most important factors in
selection. An approach to comparison of alternatives based on technical
factors and toxicology data is presented. However, it is anticipated that
toxicological data on most alternatives, and also on the currently used
materials, will be sparse.
The success of information gathering and in-plant sampling efforts
is expected to depend heavily on use of Section 308 (FWPCA) authority. Air
emission sampling would be very important to the establishrrent of an overall
process material balance and definition of process losses to the environrrent.
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2.0
INrIDDUeTlaJ
2.1
1975.
Purpose and Objectives of Task III
Task III under Contract No. 68-01-3259 was initiated December 15,
'Ihe purpose of this task was to develop a plan for:
(1)
Detailed evaluation of the invesbTent casting
industry (wax manufacture and use in casting),
including a program to determine the levels of
wastes and emissions containing polychlorinated
biphenyls (PCBs) and polychlorinated terphenyls
(PCTs) and waste disposal practices; and
follCMing:
(2)
Evaluate potential substitutes for PCBs and PCTs
in the above industries with regard to teclmical
suitability, economics, human health hazard, and
environmental acceptability.
The objectives of such a plan would necessarily include the
(1)
Verification of the magnitude of PCB and PCT wax
filler production and use;
(2)
Development of detailed process descriptions, in-
cluding waste streams, leading to a complete mass
balance for the production and use processes (in-
cluding significant variations);
(3)
Definition of quantities and concentrations of
waste streams, including waste form, abatement
teclmiques, and ultimate disposal rrethods; and
(4)
Evaluation of all reasonable alternatives to the
use of PCBs or PeTs in casting.
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2.2
Surrma:ry of Work to Date on Investrrent Casting
Under Task I of Contract No. 68-01-3259
Task I of the subject contract involves a detailed microeconomic
and teclmical study of regulatory alternatives for PCBs. This task has,
of course, included study of the use and substitution potential of deca-
chlorobiphenyl (the only type of PCB intentionally used in investrrent cast-
ing). A brief surrnary of this work is presented belCM.
Decachlorobiphenyl ("deka") is used as a pattern wax filler in
investIrent casting. About 400,000 lbs. are iITported from Italy (Caffaro)
annually by a single wax manufacturer; (1) and about 1,200,000 lbsjyear of
wax containing deka is produced (unit price about $0.70jlb; yearly sales
approximately 0.8 to 1.0 million dollars). Details of the production process
are not kna.vn. The manufacturer of the deka wax also produces other pattern
waxes which presumably contain chlorinated te:rphenyls (PCTs) as fillers.
In surrma:ry, the investrrent casting process, which is described mre
thoroughly in Section 3.3, is a lost-wax casting process in which the shape
to be cast is rrolded from wax and then invested or surrounded by a slurry of
refractory ceramic. After the ceramic mId has hardened to an appropriate
strength, the wax pattern is rrel ted or burned out leaving a mlc.ed cavity.
Mol ten rretal is then poured into the cavity, and cooled to fo:rm the casting.
Sane pattern waxes, especially those used in the casting of metal
parts requiring tight dirrensional tolerances, contain dec.:achlorobiphenyl as
the wax filler. Such waxes contain approximately 30 percent (perhaps up to
40 percent) decachlorobipheny1. It is also kna.vn that pattern waxes are re-
covered and reused several tirres to fo:rm the sprues and gates of the patterns.
Wax is apparently used an average of 2.5 tirres. During the dewaxing process
the virgin wax (used to form the pattern) and the old wax (used to fo:rm the
gates and spru.es) are collected as one mixture. Little of the wax is destroyed
in the process; therefore, it is considered probable that the investIrent cast-
ing foundries store or dispose of relatively large arrounts of used PCB-
containing wax.
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'ilie major losses of the virgin and used waxes occur during the de-
waxing of the ceramic mld. As the ceramic mld is heated to rerrDve the wax,
a small portion of the wax diffuses into pores of the mld. Later, the mld
with the trapped wax is fired in a furnace to set the mld and rerrDve the
wax. Depending on furnace conditions, the decachlorobiphenyl in the wax may
be burned or released to the atm:>sphere. At least several percent of that
used is believed to be emitted via this route.
Potentially acceptable process al temati ves for the deka PCBs could
utilize either a replacerrent filler material or an lIDfilled wax. Properties
required for a filler are: high rrelting point (over 300°C), high thermal
conductivity, lON coefficient of thennal expansion, and rn:i..nimum ("zero") ash.
Isophthalic acid is a promising filler candidate that has been used to a
limited extent, but the grade used left an ash residue. A new grade of iso-
phthalic acid, only recently conurercialized, exhibits ITnlch lONer ash and rretal
oontents. 'This grade costs about $0. 35/lb, which is oorrparable to the deka
cost of about $0.30/lb.
Prior to the use of PCBs or pcrs as fillers, lIDfilled waxes were
used. Industry claims that reverting to the use of lIDfilled waxes would in-
crease production oosts by about 10 percent. Ha.vever, new types of unfilled
waxes have recently entered the market, and it is claimed that their properties
are equivalent to the filled wax and their cost is slightly lONer ($0.60 to
$0. 65/lb) . Although the exact formulation of these waxes is proprietary, they
reportedly contain no chlorinated addi ti ves.
In sumnary, technically adequate substitutes appear to be available
for decachlorobiphenyl filler in pattern waxes. Maximum increases in costs
would be about 10 percent. 'The only producer of wax containing PCBs oould
probably change to other types with very little technical difficulty or
economic irrpact.
2.3 Use of Polychlorinated Terphenyls in Investrrent Casting
Several wax manufacturers use irrported PCI's as pattern wax fillers,
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but the arrounts are not knONYl. Since the general properties of the deka and
the PCTs are sllnilar, it is anticipated that the wax production and use pro-
cesses are sllnilar also. However, this point needs clarification.
Contacts with indusb:y indicate that the volurre of PCI's used in
wax is probably about the same as that of deka PCBs. Monsanto was the lead-
ing, and probably only, u. S. producer of PCI's prior to their voluntary
cessation of production in 1972. Dorrestic production of PCI's by Monsanto
through 1972 was as follONs: (2)
Year
Millions of Pounds Aroclor 5460
1968
1969
1970
1971
1972
8.87
11. 60
17.77
20.21
8.13
It is believed that a relatively small fraction of this production
was used in casting waxes, probably on the order of a million or so pounds per
year. Aroclor 5460 (Monsanto's trade name for their 60-percent-chlorine PCI's)
was used primarily in adhesives, lubricants, and paper coatings.
'rhe current source is Prodelec (France), which markets the naterial
as Electrophenyl '1'-60 (60 percent chlorine), which, it should also be noted,
may oontain PCB contaminants.
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3.0 CURRENT KNC»lLEDGE OF THE rnvES'IMENT CASTING INOOSTRY
3.1 General Background
'!here are currently 135 investrrent casting (IC) foundries and five
investrrent casting wax manufacturing plants in the United States. The IC in-
dustry had its start in the United States during World War II when urgent
demands for arms and aircraft parts required ITOre efficient rrethods of pro-
ducing finished, precision parts than standard machining techniques offered.
During the war the waxes used by IC foundries consisted of a blend
of carnauba wax, beeswax, paraffin, and rosins. HCMever, over the last decade
wax formulations have evolved which consist of a variety of IX>lyrreric corn-
p:Junds and other fillers such as decachlorobiphenyl and PCTs. By reducing
the wax content through lCM-shrinkage fillers (such as PCBs and PCTs) volu-
rcetric shrinkage of the ceramic ITOld is controlled. This allCMs the production
of rceta! castings with smaller dirrensional tolerances than were available with
the original unfilled waxes.
Of the 135 foundries, approximately 25 use PCB filled waxes. It is
not known hCM many foundries use per blended waxes. Since there are four wax
manufacturers which supply the PCT blended waxes and only one which supplies
the PCB waxes, it is suspected that the arrount of PeT wax blends sold to IC
foundries is at least canparable to and perhaps larger than the arrount of PCB
wax blends sold. 'Ihe five known wax manufacturing COI'Cpanies are:
1.
2.
3.
4.
5.
Yates Manufacturing Corrpany, Inc.
M. Argueso and Corrpany, Inc.
Freeman Manufacturing Corrpany
J. F. McCoughlin Company
Pentcraft Tool and Mold Inc.
The Yates Manufacturing Company, Chicago, Ill., is the sole supplier
of PCB blended waxes. The PCB compound in their wax products is decachloro-
biphenyl which makes up approximately 30 percen° of the total wax by weight. (1)
Yates currently imports deka from Caffaro S.P.A., Italy, at a rate of 300,000
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to 500, 000 lbs. per year, which corresfX:mds to the manufacture of between
1 and 1. 5 million p::mnds of deka wax per year. At a cost of $0. 70 per
fX:)lmd, (2) the annual volurre of sales of deka wax should be in the range
of $700,000 to $1 million per year.
Authorities in Wisconsin are currently studying the investrrent
casting industry in that state; they have obtained and analyzed samples of
water effluent that is usually disposed of through municipal sewage systems.
Versar corrmunications with the persormel involved indicate their data will
not be of major importance to the proposed study plan, although the data on
effluent PCB concentrations and the scope of the industry in Wisconsin will,
of course, be useful.
3.2 Principles of Investrrent Casting
'lhe principles of investrrent casting are the sane for both the solid
mId and shell processes, but the rrethod of forming the ceramic rrold differs
SOITeWhat between the bvo. Both require a pattern, gating to a central sprue,
rerroval of the pattern by rrel ting, pouring rretal into the cavity left by the
rrelted pattern, rerroval of rrold material from the cast cluster, and cutting
of castings from the sprue.
The investrrent shell process is depicted in Figure 1.
The Pattern
The process begins with production of a one pie02 heat-disposable
pattern. '!his pattern is usually made by injecting wax or plastic into a
rretal die. Dies range from simple, hand-operated single-cavity tools to fully
automated multi-cavity devices, depending on production quantities and com-
plexity of the parts to be cast.
A heat-disposable pattern is required for each unit being cast.
Each pattern has the exact georretry of the required finished part, but they
are made slightly larger in order to compensate for volurretric shrinkage
during the pattern production stage and during solidification of the rretal
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,
co
,
~
~
INJECTED
HOT WAX
PATTERN
2
1
TREE DIPPED INTO
FLUIDIZED BED OF SILICA
4
WAX PATTERNS
ATTACHED TO TREE
PATTERN
2
CENTRAL
SPRUE
POURING CUP
AUTOCLAVE DEWAXING
AUTOCLAVE
TREE DIPPED INTO
CERAMIC SLURRY
3
MOLD FIRING
~FLUE GAS
MOLTEN METAL
I
~
ft
5
FURNACE
Figure 1. INVESTMENT SHELL PROCESS
6
7
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in the rrold.
'!he pattern carries one or rrore gates which are usually located at
the heaviest casting section. The gate has three functions:
(1)
To attach patterns to the centrally-located sprue
or runner, thus fonning a tree-shaped cluster;
To provide a passage for the draining of pattern
wax once the mId is sufficiently hardened and
has been heated; and
'Ib guide ml ten rretal entering the mId cavity in
the pouring operation.
(2)
(3)
Clustering
Patterns are fastened by the gate to one or mre runners. The
runners are attached to a pouring cup. All of these parts are usually made
of wax. Patterns, runners and pouring cup caTlprise the cluster or tree
upon which the ceramic mId is fo:r:rred. The number of runners and their
arrangerrent on the pouring cup may vary considerably, depending on alloy
type and the size and configuration of the casting.
fulding
Up to the point of forming the ceramic mId, all foundries operate
in essentially the sarre manner. After assembling the pattern to a tree, hCM-
ever, they may form the mId by either the invesbrent flask process or the
investTrent shall process.
Solid Mold or Investment Flask Process
There are two invest:Irent flask techniques, depending on the type of
alloy to be poured. Ferrous alloys require highly refractory materials and
binders. The entire cluster is dipped into a ceramic slurry, drained and
stuccoed with fine ceramic sand. 'lhis step is usually repeated after the first
coating has dried. This coated cluster is then placed in an open-end rret::ll can
(the flask) which is filled with a coarse slurry of ceramic backup material
(invesbrent) . The invesbrent hardens to comprise a green mId. When the flask
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and its contents are placed into an autoclave, the whole cluster (consisti,ng
of wax patterns, runners and sprues) nelts and runs out through the pouring
ClIp. '!he resulting m:molithic rrold contains cavities of the desired casting
shape, with passages leading to them
Nonferrous alloys are cast in ceramic. rrolds bonded with plaster of
paris. '!he entire tree (heat-disposable patterns, gates, runners, and pour-
ing cup) is placed in an open-end netal flask without a first ceraIPic coating.
Invesbrent slurry is poured into the flask, completely surrounding the cluster.
Before the binder sets up, the flask is placed under vacuum to rerrove all air
entrapped during mixing of the invesbrent. v.7hen the investrrent becones hard,
patterns are nelted out exactly as in ferrous casting.
'!he Invesbrent Shell Process
'!his technique, as described in Figure 1, involves dipping the entire
cluster into a ceramic slurry, draining it., then coating it with fine ceramic
sand. After drying, the process is repeated several tines, using progressively
ooarser grades of ceramic rraterial, until a self-supporting shell has been
fomed. The thickness of the shell is usually between 3/16 and 5/8 inch.
'Ihe coated cluster is then placed in
TIel ts and runs out through the gates, runners,
ceramic shell contains cavities of the desired
leading to them.
a steam autoclave where the wax
and pouring cup.
The resulting
casting shape, with passages
Casting
funoli thic shell rrolds and solid rrolds must be fired to burn out the
last traces of pattern material and to attain a degree of penreabili ty before
the rrolds can be filled with Iretal. In the case of solid rrolds, this heating
has to proceed slcwly, in a controlled cycle which stretches over 12 to 18
hours, to avoid cracking of the rrold. The shell ITOlds, rrade of ceramic
rraterial with an extrenely lcw coefficient of expansion, can be placed
imrediately into a hot furnace. Because the she~l ITOlds have relatively
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thin walls, they can be fired and ready to pour after only a fE!N hours in
the furnaces.
'!he hot ooIds may rely on gravity alone to carry the rrolten rretal
into the intricacies of the rrold, as is oornron in sand casting, or the pro-
cess may use vacuum, pressure and/or centrifugal force in order to fai th-
fully reproduce intricate details of the wax patterns.
M31ting equiprrent employed dePends on the alloy. For nonferrous
alloys, gas fired or electric crucible furnaces are usually used. For ferrous
alloys, high frequency induction furnaces and indirect arc furnaces are carmon.
Cleaning
After cooling, oold materials are rerroved fran the casting cluster
with vibrating equiprrent. Individual castings are usually rerroved fran the
cluster by rreans of cut-off wheels, and any remaining protrusions left by
gates or runners are rerroved by belt-grinding. Generally, castings are sand
blasted for srrooth finish, then they are ready for such secondary operations
as heat treating, straightening and rnachining.
Reclaiming of Pattern Waxes
'!he present cost of virgin pattern wax is approxim3.tely $.70/lb. In
the future, it may be oore economical to reclaim wax for use as pa.ttern waxes,
in addition to its present use in gates and runners. Fu:ctherrrore, through a
precipitation rrethod, it is possible to rerrove fillers, including PCBs, from
used wax in order to prepare unfilled wax.
Improverrent of Invesbrent Casting Processes
Several inproverrents in the invesbre.nt casting techniques and pro-
cedures have been suggested by TRW Metals in Minerva, Ohio, which developed
them through a two-year Air Force contract. (3) The ~as of irrproverrent were
in wax pattern formation, oold production processes and metal pouring.
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Ir8.1ltiple
separate
Wax pattern formation techniques were improved through simultaneous
injections of the gates and runners. 'Ihe usual procedure requires
steps.
'!Wo suggestions for improveITeI1ts ~Nere rrade for the rrold production
process: (1) elimination of the drying cycle between slun:y dipping and sand
():)ating, and (2) the use of micrONave ovens to rrelt pattern wax out of the
ceramic rrold or shell.
'!he use of microwave dewaxers would have the advantage of reducing
wax emissions in flue gas and drain rondensates of autoclave ovens. HCMever,
micrcwave dewaxing may not eliminate wax losses occurring during rrold firing
as a result of wax trapped in the pores and cavities of the ceramic rrold.
3.3 Foundry Process - Use of PeT and PCB Filled Waxes
A flow chart which typifies the use of PCBs in investrrent casting is
presented in Figure 2. PCB filled waxes are purchased fran wax manufacturers
in bulk quanti ties of 10,000 or rrore pounds, sealed in plastic bags and con-
tained in boxes for shiprrent:;. The received pattern wax is stored in a stock-
room at the foundry until rrelted for the production of wax patterns. Once
rrelted, the wax is injected into a pattern die where the wax is allCMed to
solidify. The pattern die is then disassembled and the wax pattern rerroved.
Several wax patterns are produced before fanning the tree. 'Ihe fornation of
the tree entails attaching the individual wax patterns to the sprues and
gates, and after the trees are assembled, the sprues are roated with a dip-
seal wax to fill the voids on the rough sprue surfaces.
'The next step in the process is the formation of the ceramic rrold.
..This is acoomplished by dip-coating the wax trees in a ceramic slurry and a
fluidized bed of silica, and air drying of the roated tree. This process is
rep2ated several tinEs before the wax is rrelted out of the rrold.
Dewaxing is by one of three tech.Tlique~ ~ steam autoclave, microwave
oven, or flash firing in a rrold furnace. Most foundries apparently use the
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IMPORTED PCBs
PATTERN
WAX
PRODUCTION
PACKAGING AND SHIPMENT
(~'30 % PCBs, IN PLASTIC BAGS)
WAX
WAX PO DUCT ION
PA
VIRGIN WAX HEAT HOT INJECTION REMOVAL OF ADDITION OF
TTERN - PATTERNS
WAX STORAGE EXCHANGER WAX INTO DIES - SPRUES AND GATES
FROM DIES
STEAM hClAR'F'EO "'A'
OE'IIATE'R!NG 1Nl1 USED WAX HOT
HEAT '!.'AX SPRUES AND GATES COATING WITH
O?EN KETTLES STORAC~ EXCHAfI;':;:::R FOR:\IATIOr~ DIP SEAL WAX
L::;~ BJTTO~/,S TO D1?PCSAL
DIE PATTERNS
,
I
.....
W
I
l,
i
AIR
DRY!NG
/CERAMiC MOLDS
1. t',1CL D
FUf\i\J),CE
25QO'~F
I r FC~~,~/',.'!ON OF
L--t CERA:,!!C i/CL.D
BY 0 I P--COATIt~G
t,':ETAL
I~;JECTION
COOLING
f.~O~
RE:'.',CIJ,tI.L
CASTING METAL
MELTIt\G
EXCESS
M::TAL
SPRUES Arm GATES
R E ~,:.:) 'HI, L
FINAL
MACHINING
PACKING AND
DISTRIBUTION
OF CASTINGS
I NVEST;.~:::~H C;:'STI~~G
PROCESS
FIGURE 2
FLOW CHART OF PC8s USAGE IN INVESTMENT CASTING
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autoclave technique, which involves subjecting the ceramic coated trees tQ
steam until the wax within the mId is rrelted out, leaving the ceramic shell.
'Ihe rrelted wax is either disposed of or reclairred for use as sprues and gate
wax. 'Ihe nEW microNave technique involves heating the ooIds with micrONave
energy. MicrONave units of 5- and 10-kilON~tt output are comrercially avail-
able for this application. The third technique of flash firing combines de-
waxing and oold firing in one step. The ceramic coated wax trees are placed
in a furnace where all the wax is rerroved from the tree by flash firing. Most
of the wax is vaporized and leaves the furnace with the stack gases. It is
not knCMIl hON many facilities use flash firing.
If the foundry dewaxes the trees using autoclave or rnicrONave tech-
niques, the dewaxed ceramic ooIds must be fired in the oold furnace to
strengthen the ceramic and to rerrove wax residues. The ceramic ooIds are
raised to temperatures of between 1900 and 2000°F for approximately two hours.
The vaporized wax residues leave the furnace with the stack gases. The foun-
dries claim that only 1 to 2 percent of the wax remains in the rrolds before
rrold firing. This estimate of trapped or wall absorbed r,lax appears to be ION
for two reasons:
(1)
'Ihe porosity of the ceramic rrold can be as high as
30 percent, and
(2)
TrapPed waxes in the cavities of the pattern vary
in am:>unt, depe.'1ding on the pattern 's georretric con-
figuration.
After firing, the ceramics are ready for rretal pouring. The steps
involved in pouring, and the subsequent recovery of the castings are evident
in Figure 2, starting with rretal pouring.
The high cost of pattern wax has stimulated foundries to reclaim used
wax. For example, the PCB filled waxes sell for approximately 70 cents per
p:.>Und. The average weight ratio between patten wax and wax in sprues and
gates is about 40: 60. Therefore, reclaiming of used wax, especially for use
in sprues and gates, has becare a very inportant part of the foundry process.
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Recla.irnll1g involves placing the used wax in open kettles or tanks
and heating it above the boiling point of ,.,rater until all the water (from
the stearn autoclave) is eliminated. After dewatering, the reclairred wax is
reconstituted by adding Paraffin and other additives until certain rrelting-
point specifications are rret. It is clairred that wax fillers are not added
to adjust the filler content. (4)
For those foundries who practice wax reclamation on their used
wax, it is estimated that 5 to 10 percent of the wax is deliberately disfDsed
of. '!he major source of the discarded wax is probably the dregs from the
dewatering kettles.
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4.0 OUTLmE OF STUDY PLAN
A detailed study plan of the invesbrent casting industIy is pre-
sented in outline form below. Very 1i ttle of the information required has
been available heretofore from the industry or other sources. Discussions
of the various information areas, including data gathering methodology,
sources of data, sampling and analysis requirements, are presented in
succeeding sections.
4.1 Characterization of Industry Scope
4.1.1
4.1.2
Information from Producers, Importers, Distributors,
and Wax Manufacturers (includes historical data)
(1)
Quantities of PCBs and pcrs reported sold and
purchased
Formulation of waxes sold
(2)
(3)
(4 )
(5)
(6)
(7)
(8)
Arrounts of wax rrade and sold per U. S. region
Sale prices, grades, quanti ties, method of shiprrent
Impurities, such as PCBs in pcrs
~unts reclaimed, if applicable
Physical properties of products
Cost of wax production
Information from Invesbrent Casters (includes
historical data)
(1)
(2)
(3)
(4)
Arrounts of wax purchased,
stockpiled
Nature of casting products
Wax use per product unit
Costs per product unit
used, reclairred, and
-16-
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4.1. 3 Other Information - General Sources
4.2
(1)
Role of invesbrent castings in user industries -
technology, eoonomics, al ternati ves, history, etc.
Process Characterization
4. 2.1 Wax Manufacturing Process
4.2.2
(1)
Preparation of detailed flON charts, including
all process and ancillary streams and conditions
Identification of knONn or potential waste streams
plus any treabrent, with approximate quantities and
(if knONn) oompositions
Docurrentation of waste disposal :rrethods
Defini tion of process for reclamation of used wax
(2)
(3)
(4)
Invesbrent Casting Process
(1)
Upgrading of current flow chart including process
oonditions
4.2.3
(2)
Detailed definition of dewaxing alternatives (steam
autoclave, microwave oven, flash process), extent of
use, and expected future use of each
Identification and quantification of waste
using inforrnation from industry
Definition of reclamation process
(3)
streams
(4)
Sampling and Analysis Recornrrendations
(1)
(2)
(3)
(4 )
Raw materials and wax products (including impurities)
Used wax and solid waste streams
Water effluents
Air emissions (particularly exhaust from mld firing
uni t)
-17-
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4.3
(5 )
(6)
Selected process streams (as necessary)
.Applicable reclamation process streams
Alternative Technology
4.3.1
Data Requirements for Substitute Filler
(1)
Technical
dimensional tolerance requirerrents
4.3.2
o
o
o
o
o
(2) Costs
o
o
o
mel ting/ softening PJint
ash/rnetal content
heat transfer properties
coefficient of t.hermal expansion
raw rraterial costs
differential costs in wax rranufacture
differential costs in investment casting
(3)
(4)
.
o reuse/reclamation potential
Previous use history in casting processes
Environmental and health effects (see Section 4.4)
Use of Unfilled Waxes
Technical data
(1)
o
dimensional tolerance effects
heat transfer effects
o
(2)
o process changes
Cost and economic data
o
changes in operating costs per unit
net changes in product cost
economic iITpact on wax rranufacturers
o
o
o
cost of unfilled wax
-18-
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4.3.3
(3)
History of unfilled wax use in invesbrent casting
o
types used in the past
types available n~
o
Comparison of Filler Substitutes versus Use of
Unfilled Wax
(1)
(2)
Tabulation and comparison of technical and cost data
Detennination of list of IIDSt promising use al ternati ves
4.4 Environmental and Human Health Effects
4.4.1
4.4.2
Environmental and Toxicological Effects of
CUrrently Used Fillers
(1)
Survey of available literature on physical and
chemical properties, toxicology, and biochemistry
of:
o
decachlorobiphenyl
polychlprinated terphenyls
contaminants present in deka
other wax constituents
and in PCI's
o
o
o
(2)
Information gathering from researchers who have worked
or are working with the materials of interest or with
similar compounds
Environmental and Tbxicological Properties of
Potential Substitutes
(1 )
Revi8'lN of environmental effects and toxicology
literature on IIDSt promising use alternatives
Comparison of environmental acceptability with
current PCB and PCT fillers using available
infonnation
(2 )
(3)
RecoITlITEI1dation of experinental protocol necessary
to establish environmental acceptability, if necessary
-19-
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5.0
DETAILED DISCUSSION OF THE rnooSTRY S'lDDY PLAN
This section of the report presents details of the study plan for
a thorough evaluation of the invesbrent casting industry, including wax
rranufacturing.
5.1 Objectives of the Plan
Before proceeding to the details of the study plan, it is appro-
priate to restate the major objectives of the plan. The objectives are:
o
Verification of the magnitude of the PCB and
Per use.
Identification and quantification of PCB and PCT
losses to the environment.
o
o
Evaluation of reasonable alternatives to using
PCB and PCT waxes.
Evaluation of the potential utilization of con-
trol or abaterrent tedmology (where enviromrental
losses do occur) and safe handling, storage, and
transporting practices.
Evaluation of the potential rnicroeconomic iJrpact
resulting from the institution of:
(1) alternatives to PCB and PCT waxes,
(2) control or abaterrent technology, and
(3) safe handling, storage, and transpor-
tation practices.
Evaluation of environmental and human health effects.
o
o
o
5.2 Material Balance
A very imtx:>rtant aspect of the proposed plan is the developrrent of
a realistic material balance model for PCBs and Pers in the investment casting
industry. A material balance, in addition to verifying the magnitude of PCB
and PCT use, would identify the loss routes and determine the arrounts of PCBs
and PCTs escaping to the environrrent from wax manufacturing and invesbrent
casting facilities.
-20-
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5.2.1
Investrrent Casting
The first step in conducting a material balance for an investment
casting foundry is to identify all streams potentially containing PCBs and
PeI's. Figure 3 is a flo:.v chart shoNing input and waste streams. The broken
lines within the process box in Figure 3 indicate potential PCB and PCI'
escape routes via air emissions from the foundry unit processes. The solid
lines between the processes indicate the production routes of the waxes. The
solid lines at the top of the figure indicate the two general ambient air
escape routes, narrely the stack gas from the mId firing furnace and the foundry
exhaust air system. The two solid lines leaving the founclry (at the bottom of
the figure) represent PCB and PeI' escape routes: solid waste, which is
usually sent to landfills, and raw sewage, which goes to municipal sewage
treatment in mst cases. The broken line outside the facility (at the top
of the figure) indicates the possibility for inadvertent re~icling of escaped
PCBs or PCTs in stack gas or foundry air exhaust back into the foundry
facility.
As described in Section 3.0, PCB- and PCT-containing waxes enter
the foundry as pattern wax packaged in plastic lined boxes which are stored
lIDtil needed in the casting process. During mId production, when the wax
is rrelted and injected into rretal dies, wax f1..ITreS may escape. The type of de-
waxing rrethed employed by the foundries has a direct effect on the arrount and
m:::xJ.e of PCB or PCI' loss to the environrrent, not only during dewaxing but also
during process steps that follow. For example, the use of a steam autoclave,
in addition to its a.vn potential emission of PCBs or PeI's, also imparts
misture to the wax, and this water must be rerroved before the wax can be re-
used. Dewatering by evaporation at high teJ1lperature also likely contribub?s
to air emissions. Flash firing, whj_ch combines mId firing and dewaxing into
one step, probably emits high levels of PCBs or PeI's, and so far as is known,
emission controls are not used.
Solid wastes can include unreclairred used wax, excess reclairred wax,
oottans from reclamations, and wastes from spills, equiprrent cleanout, etc.
-21-
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I
I
IV
r-.,.)
PATTERN
WAX
FOUNDRY
MAKE-UP
AIR
STACK
GAS
--- --- -------- ---- -- ---
r--------------
I r----- ----- ---
I r----------
I I I
I
MOLD
PRODUCTION
WAX
STORAGE
---
---
----
r--
DEWAXING
MOLD
FIRING
FOUNDRY
AIR
EXHAUST
IDEALIZED FLOW CHART FOR AN INVESTMENT CASTING FOUNDRY, SHOWING WASTE STREAMS
WAX
RECLAMATION
DISPOSAL
SEWAGE
F1":;(RF 3
-------
J\1though process water does not appear to be used, sorre plants may use cool-
ing water. '!he steam autoclave appears to be a source of water vapor only.
5.2.2
Preparation
'!he developrrent of a material balance will be based on info:rmation
gathered during the first stages of the study, as outlined in Section 4.0.
From the collected inforrration, the investrrent casting foundries would be
categorized by:
(1)
oo.'laxing process - steam autoclave, flash firing,
microwave ovens, or others,
(2 )
Major type and status of wax used - PCB, Pel' or
other waxes,
(3)
(4)
Weight of castings produced annually,
Arrount of pattern wax (and reclairred wax) purchased
annually, and
~A1het.her or not wax is reclairred, and arrount reclairred.
(5)
Once categorized, several foundries would be selected for a corrq;>re-
hensive material balance. Based on conclusions formulated after categorizing
the foundries, it may be found necessary to study in detail as many as six
foundries in order to typify the entire industry. Table I summarizes charac-
teristics that must be evaluated. Ha.vever, this schedule could be altered
by the results of the industry study; for instance, it is not known whether
both PCB and per waxes are flash fired.
5.2.3
Sampling and Analysis Plan
'!he sampling and analysis plan for the performance of a mass balance
at each selected foundry must "Lltilize accepted and standardized sampling and
analysis rret.hods, and it should be perforrred with minimum interruption to the
foundry process. Since investrrent casting is a batch process, it is proposed
that a batch run of pattern trees (containing sprues and gates) be folla.ved
from mId production to wax reclamation and mId firing. '!he general approach
-23-
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TABLE I
2HZ\J~Z\CTERISTICS OF INDIVIDUAL FOUNDRIES BEING STUDIED
'Types and ArrDW1ts of
Pattern Wax Used
Deka-filled
PCI'-filled
Other fillers
Unfilled
Dewaxing Process
Autoclave
Hicrcwave oven
Flash firing
Other
T,vax Reclamation
AIIDunts of wax
reclaimed in COITr
parison to the
industry average
Weight of Castings
Average casting weights,
co~ared to industry
averages
-24-
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would be to start a batch run with knOl,m arrOlmts of filled patteTIl wax and
reclalired wax (both well characterized) and to trace the wax and its filler
through the invesbrent casting process. Of especial importance are weight
rreasurerrents of:
- patteTIl wax and used wax in the trees prior to ceramic
coating;
-- ceramic coated trees (wax filled) thoroughly air dried;
- combined wax and water draining from autoclave during
dSNaxing;
ceramic trees (empty rrolds) prior to firing.
All the melted wax draining fram the dSNaxer (autoclave) would be weighed
and the rroisture content determined. These data combined with PCB or PCT
emission analysis perforrred on the rrold fUTIlace stack gases would quantitate
the nagni tude of PCB or per losses during rrold firing. In addition, it is
proposed to quantitate the foundry losses of PCBs or PCTs through the air
exhaust system, the raw s~wage stream, and through solid waste disposal.
The PCB or PeT content of reclalired wax is of particular importance
since this determines the PCB or PCT content of the used wax in the tree
and gives an insight into the fate of the filler in the reclamation process;
the bottoms from the dewatering kettles may be filler-rich, or the used wax
may be filler-rich.
The protocol for conducting a sampling experirrent at a foundry might
resemble the following:
(1)
Perfonn reference gas sampling in rrold production, de-
waxing, wax storage, ~rVax reclamation, ITOld fUTIlace
areas;
(2)
Perfonn reference gas sampling on rrold
gases, foundry exhaust and foundry air
termine mass flew rates;
furnace stack
retUTIl, and de-
-25-
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(10)
(ll)
(12)
(13)
(3)
Collect reference samples of cooling water (if used) ,
intake water and raw sewage;
( 4)
Collect samples of pattern wax and
tined for use in the production of
wax trees to be follOtJed;
reclaimed wax des-
the batch run of
(5)
Perfonn gas sampling for PCBs or PCTs in rrold produc-
tion area during rrold production;
(6)
(7)
Collect samples of cooling water;
During tree assembly, weigh each wax pattern before
attaching to the sprue of the tree. The sumnation of
the individually weighed patterns will represent the
total pattern wax contained in the batch run;
(8)
Weigh the assembled trees prior to coating with cera:rmc,
since :
[weight of trees] - [weight of pattern] =
[weight of reclairred wax in batch] ;
(9)
Weigh ceramic coated trees prior to placement in auto-
clave;
Perfonn gas sampling for PCBs or 'Pcrs in dewaxing area
during dewaxing of the test batch of rrolds;
During dewaxing, weigh all the rrelted wax (and entrained
rroisture) drained from the rrold dewaxeri
Collect a sample of the rrel ted wax;
Weigh "dewaxed" trees prior to rrold firing:
[weight of ceramic coated (wax filled) trees] -
[weight of dewaxed tree] = [wax residue remaining
in ceramic rrolds]
-26-
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(14)
(15)
(16)
(17)
(18)
Perfonn gas sa:rt'pling for PCBs or PCTs in the IIDld fur-
nace area during IIDld firing of the test batch;
During IIDld firing, perfonn stack gas sa:rt'pling for PCBs
and PCTs and deteoone the stack gas ITBSS flONrate;
Perfonn gas sampling for PCBs and pcrs in the foundry
exhaust and return air streams and detennine ITBSS flow
rates;
Perfonn gas sa:rt'pling in the wax reclamation area;
Collect sa:rt'ples of waste wax (esp=cially from wax reclama-
tion areas) destined for waste disfOsal and sa:rt'ples of
newly reclaimed wax.
All sa:rt'ples would be analyzed for PCBs or PCTs using EPA approved
rrethods where applicable. In addition to assaying the PCB and PCT content,
the IIDisture content of wax samples collected from the dewaxer should be
detennined .
Analytical methodology should include ITBSS spectrorretric verifica-
tion of the presence of PCBs or PCTs in virgin wax, reclaimed wax, stack
gas, facility air exhaust, cooling water and sewage stream. Once verification
is established, analyses would presumably be conducted by gas chromatography
versus reference standards.
5.3 Wax Manufacturing
Tb date, very little is known about the wax rranufacturing process.
However, it is known that in the process PCB or PCT compounds are added in
p:>wdered fonn to the wax base. Reduction of PCB or PCT particle size prior to
mixing may be desired. lDsses of dust to the environrrent by air routes from
both size reduction and mixing operations would be expected.
-27-
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Essential to a material balance on wax manufacturing is a thorough
understanding of the wax manufacturing process. Once achieved, a material
balance program could be designed to assess the envirornrental losses. Depend-
ing on the specific processes involved, this mayor may not require a canpre-
hensive sampling and analysis program such as is outlined for the foundry
process in Section 5.2.
5.4 Sumna:ry of Results from Investrrent Casting
Industry Study Plan
IIrportant results from the investrrent casting industry study are
characterizations of:
(1)
Scope of the industry, including definition of
materials and processes used;
Product types and quantities;
Technical aspects of substitutability (use history
of alternatives, di.rrEnsional tolerance requirenents,
etc. ) ;
Use and applicability of emission controls and waste
reduction from current waxes and alternatives; and
Waste streams I losses I and disposal ITethods.
(2)
(3)
(4)
(5)
The combining of process data with the results of the sall'"pling and
analysis program will produce a definitive material balance for the casting
process and will define the waste streams and losses as in (5) above. The
in'q;ortance of accurate loss data is illustrated by the current range of esti-
mates from industry and other sources of 1 to 10 percent wax loss for the
autoclave furnace-firing ITethod; considering that t.l-}e wax is used an average
of 2.5 tiITeS, total stack losses could be as high as 25 percent of the material
purchases. With flash firing I air emission losses could be even higher. 'Ihe
program results will also provide a colTparison of the different types of de-
waxing processes in terms of losses.
-28-
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Recomrrendations to rndustJ:y, on material handlrng, storage, and
housekeeprng, should also result from the study.
5.5
Role of Section 308 Authority rn StUdy Plan
In our data gatherrng contacts with the rnvestrrent casting rndustry
under Tasks I and III of Contract 68-01-3259, we have received only limited
cooperation. Initially, the wax manufacturers would receive telephone calls
and answer sone questions, but they have recently displayed sone antipathy
toward the efforts of Versar and EPA rn gathering data on PCBs and PeTs.
Nearly the reverse has been the case with the ~Nax users (investTI'ent casting
corrpanies), who were strongly influenced by their wax suppliers until recently
when sone have becorre rrore open in giving information. HONever, this COOPera-
tion has not been rndustry-wide.
'Thus we expect generally poor industrial cooperation in the imple-
rrentation of the study plan, with the major opposition originating from the
wax manufacturers. In addition, invesbrent casting is an industry using
relatively low levels of teclmology and having little awareness of environ-
nental problems; the industry has been essentially unregulated and does not
appear to utilize even rudinentary control procedures.
"Responses to the current series of 308 inquiry letters by EPA will
be extremely helpful in the final planning and implementation of the study
plan. Authorization to enter plant premises and conduct sampling activities
to define PCBs and PCT levels in process strearns will probably be necessary
to the generation of a combined process and waste material balance. It should
be noted here that errU.ssions to air from the casting plants are expected to be
significant, and thus authorization for air emission rronitoring would probably
be essential to the study.
In sumnary, the current series of 308 letters on PCBs aYlC PCTs will
be rrost helpful to the study, but authority under Section 308 will be necessary
both for rrore detailed characterization of the industry and its processes, and
for the performing of in-plant sampling activities.
-29-
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6. 0 DISCUSSION OF ALTERNATIVES S'IUDY
At the present, there appears to be no teclmological barrier to
cessation of the use of decachlorobiphenyl and pcrs as invesbrent casting
wax fillers, although potential effects of filler substitutes or of the
use of unfilled wax on dirrensional tolerances of the cast products must be
evaluated.
A list of acceptable property values of casting ~"axes must be
generated. High melting point, high thermal conductivity, ION coefficient
of thermal expansion, and ION ash content are the necessary properties of a
filler substitute. In addition, the substitute should be minimally injurious
to the environrrent and should pose no threat to human health. Minimal eco-
nomic irrpact resulting from increases in raxv material costs is also obviously
desirable.
Information on the teclmical and cost aspects of filler substitutes,
and on the alternative use of unfilled waxes, must be obtained from industry
sources since there appears to be very little literature applicable to this
prohlem; and because the industries involved are not teclmically oriented,
much of the information which will be available will consist of personal
opinions or observations of knowledgeable figures in the casting and wax pro-
duction industries.
If the hypothesis that the advantages of PCB and PCT fillers arise
from physical and not specific chemical properties of the wax fonnulations
is correct, then teclmically acceptable alternative formulations should be
available. Of course, substitute fillers will have to be adequately dem:m-
strated before an industry-wide changeover can occur, and the effects on in-
dustry cost structure will also have to be shoNn to be sufficiently small for
the invesbrent casting process to remain corrpetitive.
Once a list of acceptable property values of fillers is available,
-30-
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and is found to be generally agreeable to the wax users, t.he search for sub-
stitutes can be ~.videned. At present, of course, the rrost promising alterna-
tives are those vmich already have sorre use history (e.g., isophthalic acid
filler(5)and unfilled formulations(6)),and the study of these would have the
highest priority. Use history on other fillers would be sought from industry.
At the conclusion of the study, a complete tabulation of promising
alternatives should be prepared, including use histories, physical and chemi-
cal properties, raw material costs, net changes in operating costs, estimated
net effects on product costs, and environrrental acceptabilities. The list
'NOuld be designed for easy comparison of alternatives. Economic irrpact of
each would be determined only in terms of a relative ranking.
The folla.ving is a brief tabulation of the potential alternatives
considered to date. For comparison purposes, the decachlorobiphenyl raw material
cost is about $0.50jlb and the deka-filled wax sells for about $0.70jlb.
Isophthalic acid - Amoco Chemicals Corp., Joliet, Ill. (7)
.
Grade
IPA 85
IPA 99
IPA 110
IPA 220
Cost in Bulk
$ 0.24jlb
$ 0.27jlb
$ 0.31jlb
$ O.35jlb
Comrrents
High ash
Previous use history
Being phased out
New - low ash
Polystyrene - various producers (J:)a.v, Monsanto, Foster-Grant, etc.)
Cost in bulk - $ O. 40 jlb
Estimated additional process cost -
$0.08jlb filler
New Unfilled Waxes - Freeman Mfg. Co., Cleveland, Ohio
Cost in bulk - $ 0.60 - 0.65jlb
Cornposi tion unknCM'n
Estimated net product cost increase - 9 percent
-31-
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7.0
DISCUSSION OF N'TVIIDNMENTAL QUALITY AND
HUW\N HFJUirn EFFECTS PORTION OF STUDY
7.1
Sources of Information
There is very little toxicological information available on deca-
chlorobiphenyl and Pcrs. However, the overall PCBs problem is of great
general interest, and it is anticipated that useful acute and subchronic
data should be available within six rronths. The nature of impurities in
these materials needs to be defined and related to their toxioological
properties.
with regard to isophthalic acid, a oonsiderable body of literature
is available on phthalic acids and phthalate esters, but their environmental
fates are not knONrl. Degradation routes, properties of degradation products,
and other information needed for an assessrrent of environmental acceptability
havenot been investigated in depth, which is probably also the case for rrost
other filler substitutes.
It is apparent that
information for this phase of
toxicologists experienced with
prerequisite to the oollection
toxicologists will be an i.mp:)rtant source of
the study. Having kno".,rledge of and access to
the materials of interest will be a necessary
and interpretation of available data.
'llie follCMing is a tabular surrmary of the areas of published work
to date on Pel's:
Researcher (s)
Area of Interest
IDcation
Hutzinger, o.
Hepatic and gastric effects
in primates
Environrrental distribution
Uni v. of Wisoonsin
Pathology Dept.
Nat. Res. Council of
Canada, Halifax, N.S.
Center for Disease Con-
trol, Atlanta, Ga.
Allen, J. R., et al
Kimbrough, R. D.
General toxioology of re-
lated cornp:>unds
-32-
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Zitko, V., et al
Distribution, aquatic
effects
USDA Animal Husbandry
Lab., Beltsville, Md.
Research Bel. of Fisheries,
Canada, St.Andrews, N.B.
Cecil, H. C., et al
Avian effects
7.2
Comrents on Protocol for the Evaluation
of Potential Substitute
Although absolute safety is the goal of society, it is never
achieved. However, toxicological procedures are available to minimize risks.
A standard set of protocols for safety testing that could be used in all
situations does not exist. In the present case the arrounts of deka and pcrs
released to the general environment through investment casting activities
is unknown, though e.'1lissions to air could conceivably. be as high as 200,000
lbs/year, with high concentrations occurring in the vicinity of some plants.
Because of the potential for significant human eX{:X)sure to substi-
tute materials in investment casting, it seems reasonable that substitutes
should undergo the sarre chemical and toxicological studies required of food
addi ti ves . '!he ITOst appropriate test procedures are those which will avoid
the problems that have been encountered in the widespread use of PCBs. Cer-
tainly acute toxicity studies in at least two species by oral and dermal ex-
posure (and, where appropriate, by inhalation) should be perfomed. '!he ob-
servation period should be at least 21 days. 'The material under study should
also contain typical levels of the inpurities likely to be encountered in a
mass production situation.
Subchronic toxicity studies of a minimum of 90 days should also be
perfomed, the purpose being to assist in the setting of dosage levels for
studies of chronic toxicity. Depending upon the result of the acute dermal
studies, sub chronic dermal studies may also be necessary - Eye and skin irri-
tation studies should be perfomed, too. Certain chemicals can be expected
to produce acnefonn eruptions, sensitization, photosensitization, or other
-33-
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irritating or rorrosive effects.
The single ITDst linportant test of a potential environmental ron-
taminant, whether it be the parent carq:x:mnd or its degradation products, is
the so-called chronic toxicity study. These studies when perfomed in rodents
are generally carried out for at least one generation of test animals; in
dogs, or other rorrparable species, tests last at least two years. If suffi-
cient numbers of animals are used, the chronic toxicity study can reveal
oncogenic acti vi ty . In designing chronic toxicity studies, ronsideration
must be given to many factors, including the effects observed in the acute
and subchronic studies and the estimated roncentration and duration of human
exposure in other instances where the corrpound being tested has been used;
for exarrple, occupational exposure. For the chronic studies the best test
species ,,,ill be that one in which the rretabolism of the rorrpound being tested
ITDst closely resembles that of man - though it is rerognized that such a de-
termination may be extremely difficult.
At present, it appears that the full set of studies outlined above
has not been perfomed on decachlorobiphenyl or Pel's, and it is unlikely that
such studies have been perfomed on any of the potential substitutes. For the
purposes of the study outlined herein, available data should be analyzed and
used to the extent possible to COJT"q?are environrrental sui tabili ty . One of the
outputs of the study should be a detailed protorol for testing of promising
substitutes in the event that insufficient information is presently available
to determine environrrental suitability.
-34-
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8.0
REFERENCES
1.
SolOlTOn, P - (Yates Manufacturing Co., Chicago, Illinois), Personal
Communication, September 9, 1975.
2.
Lewis, W. H. (President, Signicast Co:rp., 9000 North 55 St.,
Milwaukee, Wise.), Staterrents during Lecture of Invesbren.t Casting
Institute Meeting, October 4, 1975.
3.
AFML-TR-74-237, "Mfg. Methods for Production of Quality Supera110y
Engine Parts," DOC Acquisition No. AD B007400L.
4.
Wurster, W. (General Manager, Consolidated Casting Corp., 2425
Carolina St., Dallas, Texas), Noverrber 5, 1975.
5.
Ed.,rards, Dan (C1icago Laboratory - Standard oil Co., Arroco Chemical
Corporation, Joliet, Ill.), Personal CoITl11UI1ication, October, 1975.
6.
Davidson, R. (Freeman Manufacturing Canpany, Inc., 1315 Maine Ave.,
Cleveland, Ohio), November 1975.
7.
Connelley, J (New York Office, Standard Oil Co., Arroco Chemical
Corporation, Joliet, Ill.), Personal Communication, October 1975.
-35-
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CHAPlt:R 2
FORHAT
SCIENTIFIC AND
TECHNICAL PUBLICATIONS
1 AfPORT NO.
TECHNICAL REPORT DATA
(PI(as~ rcad fnstructtonJ on the rncrse b(fore [amp/clinK)
2. 3. RECIPIENT'S ACCf:SSION NO.
4. TITLE AND SUOTITLE yveloprrent of ,"lStudv "Dlan for 5. REPORT DATE
n~f' 't' += P -7 L. ,TaD'1ClJ:"'T 1976
Je lnl lon OL PCBs usage, \ 0.<:; :.,,,<0;, and Poten- 6. PERFORMING ORGANIZATION CODE
tialSubst. in ll1J-}e Tnv8strrent CC1stina Ind.
7. AUTHORIS}
8. PERFORMING ORGANIZATION AEPORT NO.
,Tarres D. Barden anrl T:>O~rt L. 9urfep
474.-3
3. PERFORMING ORGANIZATION NAME AND ADORESS
10. PROGRAM ELEM(NT t,jO.
'n:;;p,S 7'. ~ r JC .
6621 Flectronic Dr.
springfield, pC'! 0 22151
11. CONTRACT/GRANT NO.
68-01-3259
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. ~vironITEntal Protection
Office of Toxic c;ul-Jstances
''lashinqton, '). C. 20460
?\gencv
15. SUPPLEMENTARY NOTES
16,I\BSTRACT
"\. studv plan, designed to define the usage of rnlv-
chlorinated biphenyls (PCBs) and terphenyls (PCTs) in the
investITEnt casting industry, Tvi'lS developed under the sub-
ject task. Current knot/ledge was reviewed and used as input
to the study plan developrrent. ~J!ethods of infonnation
gatl1ering and data sources, as required to define industry
scope and technoloqv, 'vastes, and substitution technology,
'vere also determined.
a.
DESCRIPTORS
KEY WORDS AND DOCUMENT ANAL V$I$
b.IOEf-JTlFIERS/orEN f.NDED TEAMS
c. COSA TI ncld/Group
17.
Polvchlorinated Biphenyls
Polychlorinated terphenyls
Investment Casting
Casting \'lax Fillers
Release U
f..MENT 19. ~(CURITY CLASS (11111 R~PQrt) 21. f~O. Of PAGt:S
nlimited unclassified 40
20 SECURITY CLASS rJ'JJis PQg~) 22. PAICE
unclassified
~__.r~'...-
I~. OlSTRIBU110N STAT
EPA Form 2120-t (9.73)
I
L-----~JR;J;
TN 3
5-14-74
Figurp 2-2.
Tcchnical Report Data l'd~""
(P11rt 1 of 2)
CHAP 2
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