United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA 450/3-88-004
June 1988
Air
Cadmium Emissions
From Pigment and
Stabilizer
Manufacturing —
Phase I Technical
Report
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EPA-450/3-88-OO
Cadmium Emissions from Pigment and
Stabilizer Manufacturing — Phase I
Technical Report
Emission Standards Division
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park NC 27711
June 1988
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TABLE OF CONTENTS
Page
I. DEFINITION OF SOURCE CATEGORIES 1
A. Pigment Manufacturing 1
1. Plants in operation 1
2. Processes 1
3. Projections of industry growth ' 4
B. Stabilizer Manufacturing 5
1. Plants in operation 5
2. Processes 5
3. Projections of industry growth 7
II. EMISSIONS AND CONTROLS 7
A. Pigment Manufacturing 9
B. Stabilizer Manufacturing 9
III. PUBLIC HEALTH RISKS 10
A. Background 10
B. Results 11
IV. POTENTIAL FOR IMPROVED CONTROL 11
A. Pigment Manufacturing 11
B. Stabilizer Manufacturing 15
V. REFERENCES 15
11
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LIST OF FIGURES
Figure Page
1 Process flowsheet for the production of cadmium
pigments 3
2 General flowsheet for the production of powdered
cadmium stabilizers 6
LIST OF TABLES
Table
1 Cadmium Emission Estimates for Pigment
and Stabilizer Plants 8
2 Summary of Modeling Results for Pigment
and Stabilizer Plants 12
3 Risk, Incidence, and Costs for Each Control
Option at Pigment Plants 14
iii
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TECHNICAL REPORT:
CADMIUM PIGMENT AND STABILIZER MANUFACTURING
I. DEFINITION OF SOURCE CATEGORIES
A. Pigment Manufacturing
1. Plants in operation. At present there are four plants in the
U.S. that produce cadmium pigments: Ciba-Geigy in Glens Falls, New York;
H. Kohnstamm & Company in Newark, New Jersey; Harshaw/Filtrol Partnership
in Louisville, Kentucky; and SCM Corporation in Baltimore, Maryland.
2. Processes. Cadmium pigments are stable inorganic coloring agents
that are produced in a range of brilliant shades of yellow, orange, red,
and maroon. The cadmium pigments are based upon the compound cadmium
sulfide (CdS), which produces a golden yellow pigment. Partial
substitution of cadmium in the crystal lattice by zinc or mercury and
substitution of sulfur by selenium form a series of compounds making up
the intermediate colors in the lemon-yellow to maroon range of colors.
The pigments are fine, discrete particles of colored powder with diameters
of about 1 micrometer, which are distributed and suspended in the material
to produce a uniformly colored product. Cadmium pigments have excellent
heat stability which makes them very useful in high-temperature
processing. Cadmium pigments primarily are used in plastics but also are
used in some coatings and ceramics.
There are two general types of cadmium pigments produced in the
U.S. Pure pigments refer to the CdS or cadmium selenide pigments that
typically contain approximately 65 percent cadmium.2 Chemically pure
cadmium yellows and sulfoselenides are used full strength when low pigment
loadings are wanted (because less pigment is needed to achieve the desired
color) for example, in the manufacture of color concentrates for
plastics. Lithopone pigments are pure cadmium pigments that have been
diluted with barium sulfate. The average cadmium content of lithopone
pigments is approximately 26 percent by weight.2 Lithopones have only
one-half the tinting power of pure pigments; "but when high pigment
loadings can be tolerated, the lithopones offer tinting strength and
hiding power that compare, on an equal cost basis, with chemically pure
pigments. The greatest use of the lithopones is in the coloring of
plastics with dry blends.
-------
The production of all cadmium pigments is structured around one
generic process which is illustrated in Figure 1. However, each of the
cadmium pigment manufacturers has developed various proprietary methods
for generating pigments with particular color shades and properties.
These proprietary modifications involve altering the portions and types of
ingredients used, varying the calcination time, and adding or deleting
steps such as filtration, washing, drying, blending, and grinding. For
the purposes of this report, only the generic cadmium pigment production
process and its cadmium emission sources are described. Plant-specific
process description data have been provided to EPA by the four plants in
question, but these data have all been labeled confidential by the
companies, and, therefore, cannot be presented here.
The basic raw materials for the production of cadmium pigments are
pure solutions of either cadmium sulfate (CdSOJ or cadmium nitrate.
Cadmium sulfate is predominantly used. These materials either are bought
in bulk in liquid form or are produced onsite using cadmium metal or
cadmium sponge (a porous, high-surface-area form of cadmium metal) and the
appropriate acid. The CdSCU solution is then mixed with variable amounts
of an aqueous solution of sodium or other alkali sulfi'de (depending on the
desired color) in a precipitation reactor. This procedure causes CdS to
precipitate in crystallographic form. The CdSO,, is reacted with an alkali
sulfide-selenide to produce pigments of a red shade (cadmium sulfo-
selenides).
Upon completion of the batch process precipitation reaction, the
precipitates are filtered from solution, washed, and dried. The dried
precipitates are very fine colored particulates; however, they possess no
pigment properties at this point. The true colors and properties of the
pigments are developed during the calcination or roasting operation.
Calcination involves heating the pigment precipitate material in a furnace
to a temperature of from 550° to 650°C (1022° to 1202°F). This process
converts the pigment material from a cubic to a more stable hexagonal
crystalline structure. The calcined pigment material is then washed with
hydrochloric acid to remove the remaining soluble cadmium particles. The
product of this procedure is again washed with water, filtered, and .
dried. The final cadmium pigment emerges as a filter cake, which is
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II*.
T
•*»i?iof
•ultt4*
"P"
«•-
•
i>i,i..i
•
££1-^
Denotes
sources.
cadmium emis:;i(
Figure 1. Process flowsheet for the production of cadmium pigments,
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either ground and packaged as a final product or is.further processed
(e.g., blended) before final packaging.
The process just described predominantly applies to the production
of pure cadmium pigments. Lithopone cadmium pigment production can be
incorporated into this overall process by the two methods shown in
Figure 1. The first method involves the mechanical blending of barium
sulfate with the pure cadmium pigment produced by calcining. The similar
particle size and specific gravity of barium sulfate and the cadmium
pigment enhance the mixability of these compounds. The second method of
lithopone production involves adding the barium compound before the
pigment mixture is calcined. A more thorough and efficient pigment mixing
is achieved using this procedure. Barium is typically added to the
precipitation reactor in this process in the form of barium sulfide. Some
of the sodium sulfide normally used is replaced by the barium sulfide.
Upon reaction with the CdS04 solution, barium sulfate is coprecipitated
with the CdS. The rest of the cadmium pigment production process proceeds
as described above, and the entire coprecipitate is calcined and further
processed as needed.
Cadmium pigment products are generally sold as homogenous powders
with a typical particle size of 1 micrometer (ranging from 0.1 to
3.5 micrometers). However, depending on the ultimate application, they
can be supplied in other forms. For the plastics industry, cadmium
pigments are sometimes processed into predispersed forms such as master
batch pellets. These pellets are cadmium pigments that have been
incorporated or dispersed into compounded polymer resins. Other forms in
which cadmium pigments are supplied to the plastics industry are paste
concentrates and liquid colors, both of which allow pigment to be added to
plastic resins at different stages of the production process.
3. Projections of industry growth. In general, cadmium pigments
account for 25 percent of the worldwide consumption of cadmium. Hydrated
ferric oxides and lead and zinc chromates can be substituted in yellow
color range applications; however, these materials lack the heat stability
important in high-temperature molding of plastics. In the red color
range, ferric oxides can substituted for cadmium, but the resulting colors
lack high brilliance. Demand in 1983 for U.S.- consumption of cadmium for
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pigments was 600 metric tons. The projected consumption in 2000 is
700 metric tons. No new plants are expected because existing facilities
that are currently operating at less than 100.percent of capacity are
expected to be able to meet future demand.
B. Stabilizer Manufacturing
1. Plants in operation. Barium/cadmium stabilizers, also called
organo-cadmium soaps, are salts of long chain fatty acids. They can be
used as liquids containing 1 to 4 percent cadmium or as powders containing
7 to 15 percent cadmium. At present, there are five plants in the U.S.
that produce liquid and/or powdered cadmium stabilizers: Ferro
Corporation in Bedford, Ohio; Interstab Chemicals in New Brunswick, New
Jersey; R. T. Vanderbilt Chemical Company in Bethel, Connecticut;
Synthetic Products in Cleveland, Ohio; and Witco Chemical Corporation in
Brooklyn, New York.
2. Processes. Cadmium-containing stabilizers are used to retard
polymer degradation that occurs in polyvinylchloride (PVC) when it is
exposed to heat and ultraviolet light. Cadmium-based stabilizers are
usually mixed with barium salts to make highly effective, long-life
stabilizers that have no adverse effect on the processing of PVC products
and do not change the properties of the products during service.
Cadmium/zinc stabilizers work in a similar manner to barium/cadmium
stabilizers but are not as effective in maintaining color and clarity and
are not as long lasting. Commercial barium/cadmium stabilizers are
produced in liquid and solid forms.
The stabilizer production process can be highly variable because
many of the stabilizers produced are custom blended for specific
applications. Liquid stabilizers are prepared by dissolving CdO in a
heated solution of the relevant organic acid and an inert organic
solvent. Following the slow acid-base reaction, the water produced is
driven off by heating. The product is filtered, and the solution of the
cadmium soap is packaged in drums for sale.6
Figure 2 is a simplified flow diagram for powdered stabilizer
production. Powdered stabilizers are produced by reacting the relevant
organic acid with caustic soda to make a soluble sodium soap. A solution
of cadmium chloride is prepared by dissolving cadmium metal or CdO in
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Cadmium
Organic Acid
Catalyst
Steam
I
Steam Additives
1 1
Cadmium
Reactor
•
AAA 4 f ^ Mf»a
Reactor
(Optional)
Centrifuge
1
r
Grinding
•
Additives
Blending
•
Blending Drying
• •
• Additives
i
Final •», Cat
Packaging Sta
* PK,
Final
Packaging
Washing
Denotes potential cadmium
emission sources.
Cadmium
Stabilizer
Product
figure 2. General flowsheet for the production of powdered cadmium stabilizers.
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acid. The sodium salt of the organic acid is added to the cadmium
chloride solution at an elevated temperature to precipitate the cadmium
soap. The resulting slurry is dewatered, and-the solid stabilizer product
is washed, dried, possibly blended, and packaged. After the basic
cadmium stabilizer has been produced, additives and moistening agents may
be combined with the soap to create the product required by specific
customers. The number and sequence of grinding, blending, and packaging
operations that are performed vary depending on the exact product to be
made.6
3. Projections of industry growth. As plastic stabilizers,
organotin compounds are the most efficient, but cadmium compounds are
preferred due to their lower cost. Lead stabilizers are relatively
inexpensive and effective, but their toxicity and vulnerability to
staining by sulfides in the air are major disadvantages. The 1983 demand
for cadmium use in stabilizers was 560 metric tons. The projection for
2000 is 800 metric tons. No new plants are expected because existing
facilities are currently operating at less than 100 percent of capacity
and are expected to be able to produce the additional stabilizers needed
to meet demand.
II. EMISSIONS AND CONTROLS
The emission estimates and corresponding risk and cancer incidence
for each source in each source category are based on the best available
information. In many cases, test data were not available, and emission
estimates" were generated by plant personnel. In other cases, test data
from one plant were used to generate an emission factor for use on similar
equipment at other plants. The factors that contributed the most
uncertainty to the estimates were the determination of the actual hours
per year of operation of the control equipment (due to the batch nature of
most of the processes and several batch processes ducted to a single
control device) and the cadmium content of the material being processed
(due to the large number of products with differing cadmium contents
produced in each piece of equipment). Although the source test program
helped to reduce the uncertainty of the emission estimates at the pigment
plants, a more extensive test program would be needed to remove all
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TABLE 1. CADMIUM EMISSION ESTIMATES FOR PIGMENT AND STABILIZER PLANTS
Cadmium
emissions,
Category/plant Mg/yr
Pigment Manufacturing
Ciba-Geigy, Glens Falls, N.Y.
H. Kohnstamm, Newark, N.J.
Harshaw/Filtrol, Louisville, Ky. .
SCM Corp., Baltimore, Md.
Total
Stabilizer Manufacturing
Ferro Corp., Bedford, Ohio 0.0032
Interstab Chemicals, New Brunswick, N.J. 0.0054
R. T. Vanderbilt, Bethel, Conn. 0.0084
Synthetic Products, Cleveland, Ohio 0.042
Witco Chemical Corp., Brooklyn, N.Y. Q.Q32
Total 0.091
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uncertainty from these estimates. Table 1 presents the emission estimates
for each pigment and stabilizer plant.
A. Pigment Manufacturing
It is estimated that 0.94 megagram (Mg> of cadmium as CdS is emitted
annually from the four plants. The emission estimate for each source at
each plant was based primarily on information provided by plants in
current and previous Section 114 responses and EPA source tests at two
plants. Ciba-Geigy provided emission rates for each source based on test
data from the same or similar equipment. Emission rates along with
typical annual operating hours per year for each process unit or control
device and the cadmium content of the material processed were used to
calculate annual emissions. In cases where test data or emission factors
were unavailable for a process unit controlled by a baghouse, the annual
amount of dust collected by the baghouse, the baghouse design efficiency,
and the cadmium content of the collected dust were used to estimate
cadmium emissions.
Reactor charging for CdSO,, production is uncontrolled at three
plants and is controlled by a low-energy wet'scrubber at Harshaw/Filtrol.
Calcining operations at all four plants" are controlled by wet scrubbers.
Drying operations are uncontrolled at three plants and controlled by a
low-energy wet scrubber at Harshaw/Filtrol. Grinding, blending, and
packaging operations are typically controlled by baghouses at each of the
four plants. Fugitive emissions that occur inside buildings during the
handling and transfer of cadmium-containing materials are typically
captured by hooding and eventually ducted to a control device.
B. Stabilizer Manufacturing
It is estimated that 0.09 Mg of cadmium as barium/cadmium stearate
and CdO is emitted annually from the five plants. The emission estimate
for each source at each plant was based primarily on Section 114 responses
and test data provided by the plants. An emission factor for CdO charging
to a reactor developed from Interstab Chemicals test data was used to
estimate these emissions at the other stabilizer plants. The same mass
balance procedure discussed above for processes controlled by baghouses
was used on stabilizer sources for which data were unavailable.
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The only potential participate cadmium emission source from liquid
stabilizer production is the charging of powdered CdO. to the organic acid
solution. This process is uncontrolled at one plant and controlled by wet
scrubbers at all the other plants. Potential, emission sources during
powdered stabilizer production include CdO production (only at one plant);
charging CdO to the reactor; and drying, blending, and packaging of the
final product. The one CdO production process is controlled by a
baghouse. Drying operations are typically uncontrolled. Blending and
packaging operations are controlled by baghouses at all five plants.
III. PUBLIC HEALTH RISKS
A. Background
Risk assessment is the process used by EPA to develop quantitative
estimates of public health risks associated with individual and population
exposure to a hazardous or toxic air pollutant. The resultant estimates
are considered by EPA to be rough but plausible upper-bound approximations
of the risks. Two measures of risk are calculated. One is maximum
individual risk and the other is aggregate risk. Maximum individual risk
is an estimate of the probability of contracting cancer experienced by the
person or persons exposed to the highest predicted annual average
concentration of the pollutant. Aggregate risk is an estimate of the
increased number of cancer cases for the entire population after 70 years
of continuous exposure. It is expressed in terms of annual incidence or
number of cancer cases per year.
The estimates are calculated by coupling a numerical constant that
defines the statistical exposure-risk relationship for a particular
hazardous pollutant with estimates of public exposure to the pollutant.
The numerical constant used by EPA in its analysis of carcinogens is
called a unit risk factor. It represents an estimate of the increase in
cancer risk occurring to a hypothetical individual exposed continuously
over a lifetime (70 years) to a concentration of 1 microgram per cubic
meter (yg/m ) of the pollutant in the air the individual breathes. For
cadmium, the unit risk factor is estimated to be 1.3xlO~3 or 1.8 chances
in 1,000.
10
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Estimates of public.exposure are derived using dispersion models and
census data contained in EPA's Human Exposure Model (HEM). Dispersion
models are used to predict concentrations of a pollutant in the ambient
air at varying distances in all directions within a 50 kilometer radius
from a stationary emission source. By inputting emission estimates and
stack parameters such as height, gas velocity, gas temperature, and
diameter, the model is able to predict ambient pollutant concentrations
around the plant. By combining the predicted ambient concentrations with
population data, both the number of people exposed and their levels of
exposure can be calculated.
B. Results
Emission estimates were generated for each of the sources at all of
the plants in both categories. Each source at each plant was modeled
separately and generated its own maximum individual risk (expressed as a
probability for an individual) and aggregate risk (expressed as
statistical cases per year). The risks from all sources at a particular
plant were then summed to provide maximum individual risk and aggregate
r>sk for that plant. Table 2 summarizes the risk analysis results for the
pigment and stabilizer plants.
IV. POTENTIAL FOR IMPROVED CONTROL
A. Pigment Manufacturing
As shown in Table 2, only one of the four pigment plants has a
maximum lifetime risk in excess of 1x10" , and none of the plants has an
annual incidence in excess of 0.01 case/year. Each source at each plant
was evaluated on the basis of the actual outlet particulate matter
concentration to determine the potential for improved control. If the
existing particulate matter emissions were less than or equal to
0.005 gr/dscf (the lowest particulate matter standard that would likely be
technically enforceable for this source category) or if the source was
already equipped with a baghouse, no further evaluation of improved
control was performed because baghouses are considered BDT. If, however,
the particulate matter emissions were greater than 0.005 gr/dscf, control
options for achieving this level were developed and control costs were
calculated. Based on this analysis, two plants showed potential for
improved control. Control options evaluated included installing baghouses
11
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TABLE 2. SUMMARY OF MODELING RESULTS FOR PIGMENT AND STABILIZER PLANTS
Category/pi ant
Cancer
incidence,
case/yr
Maximum individual
risk, xlO"
Pigment Manufacturing
Ciba-Geigy
H. Kohnstamm
Harshaw/FiHrol
SCM Corp.
Total
Stabilizer Manufacturing
Ferro Corp.
Interstab Chemicals
R. T. Vanderbilt
Synthetic Products
Witco Chemical Corp.
Total
0.0096
0.0044
0.0046
O.OQ24
0.021
0.0001
0.0004
0.0002
0.0018
0.0102
0.013
3.34
0.18
0.56
0.49
0.0497
0.0317
0.131
0.383
0.230
12
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for currently uncontrolled sources and high-energy venturi scrubbers for
sources currently controlled by low-energy scrubbers for sulfur dioxide
control. Table 3 presents the emission and risk reductions attributable
to improved control at the two plants.
It was assumed that the baghouses currently in use are designed
properly and are well operated and maintained. However, there are two
bag-type collectors used at Harshaw/Filtrol for which emissions exceed
greatly 0.005 gr/dscf (0.5 and 0.8 gr/dscf based on a mass balance around
each collector). These collectors are used only when pigments are being
transferred between tote bins, and, therefore, annual cadmium emissions
and resulting risks are low (less than 6 kg/yr each and less than 4xlO"5,
respectively). The incidence from these two sources is 0.0001 case/yr.
Because of the small amount of emissions (6 percent of the total plant
emissions) and the low risk and incidence, improved controls were not
evaluated for these two sources.
The Calvert venturi scrubber model was used to evaluate cases where
a higher energy wet scrubber was required to achieve an emission level of
0.005 gr/dscf. This computer model predicts the pressure drop needed to
achieve a certain particulate removal efficiency given the gas velocity in
the venturi throat, the mean particle size, and the inlet loading. These
parameters were developed from the background information collected during
the study and from specific information provided by the plants about the
gas stream being modeled. The scrubber control options presented in
Table 3 reflects the results of the modeling effort to determine the
pressure drop needed to attain an emission rate of 0.005 gr/dscf.
The total emission reduction possible for the two plants is:
0.31 Mg/yr for Ciba-Geigy and 0.031 Mg/yr for SCM Corporation. As shown
in Table 3, the capital costs of achieving this emission reduction range
from $56,000 at SCM Corporation to $677,600 for Ciba-Geigy. The
annualized costs of operating the improved control equipment range from
$22,000 to $154,000. The cost/benefit ratios range from $18,300,000/1ife
to $44,000,000/1ife including a particulate removal credit of $3,300/Mg.
B. Stabilizer Manufacturing
As shown in Table 2, the results of the risk analysis indicated that
one plant, Witco Chemical Corporation, had an annual cancer incidence of
approximately 0.01 case/yr. Additional evaluation revealed that none of
13
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TABLE 3. RISK, INCIDENCE, AND COSTS FOR EACH CONTROL OPTION AT PIGMENT PLANTS
Plant/source
Ciba-Geigy,
Glens Falls, N.Y.
Calciner load
and dump hoods
Existing control, emissions Improved contro) option
Uncontrolled, 0.019 gr/dscf Baghouse for hoods (99.51 efficient)
each
Emission
reduc- Incidence
tion, kg reduction,
Cd/yr case/yr
312 0.0025
Capital
cost, $
560,000
t/life for
Annual improved •
cost, S control*
110.000 44,000,000
VMg
emission
reduct ion
353,000
Calcining
Impingement US (pressure Venturi MS on calctners (pressure
drop=6 in.), 0.0071 gr/dscf drop=10 in.), 0.005 gr/dscf
110 0.0010 117,600 41,800 41,800,000 373,000
SCH Corp..
Baltimore. Md.
Red calcining
Yellow calcining
Venturi US (pressure drop*
30 in.), 0.0091 gr/dscf
Venturi MS (pressure drop*
20 in.), 0.04 gr/dscf
BH on hoods and venturi MS on calciners
Venturi MS (pressure dropMO in.) to
control hoods and calciners.
New venturi WS on each (pressure drop=
40 in.), 0.005 gr/dscf
422 0.0035 677.600
422 <0.0035 336,000
31
0.0011
0.0001
56,000
151,800 43.400,000 360.000
154,000 44,000.000 365.000
22.000 18.300.000
710.000
^Includes a particulate recovery credit of $3,300/Mg.
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the sources at this plant had the potential for improved control (i.e.,
all sources were already controlled by well-designed and -operated
baghouses that are considered BDT and/or had particulate matter emissions
less than or equal to 0.005 gr/dscf). Therefore, improvements in existing
control that are feasible for the stabilizer source category would not
significantly reduce the risk from cadmium.
V. REFERENCES
1. Technical Notes on Cadmium: Cadmium Production Properties and Uses.
Cadmium Association, London, and Cadmium Council, New York. Reedprint
Limited, Windsor, Berkshire, England. 1980. pp. 3-5.
2. Background Information Document for Cadmium Emission Sources. Final
Report. Radian Corporation. May 1985. pp. 148-168.
3. Lynch, R. F. Cadmium Council, Inc. New York, New York. "Color It
Cadmium When You Need the Best." Reprint from Plastics Engineering,
April 1985. pp. 1-2.
4. U.S. Bureau of Mines. Cadmium: Mineral Facts and Problems. 1985
Edition, pp. 6, 8.
5. Technical Notes on Cadmium: Cadmium in Stabilizers for Plastics.
Cadmium Council, Inc. New York. 1978. pp. 1-4.
6. Ref. 2, pp. 180-189.
15
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ADDENDUM TO TECHNICAL REPORT FOR THE PHASE I STUD.Y OF
CADMIUM EMISSIONS FROM CADMIUM PIGMENT AND STABILIZER MANUFACTURING
Comments on the technical report were received from Ciba-Geigy,
in a July 1, 1987, letter. The company provided cadmium emission estimates
for the Glens Falls pigment plant. In addition, the company reported their
plan to totally cease pigment production at the Glens Falls facility in 1988,
A phone call to Ciba-Geigy on May 11, 1988, confirmed that the plant had
been shut down and dismantled.
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
EPA-450/3-88-004
3. RECIPIENT'S ACCESSION NO.
ITLE AND SUBTITLE
Cadmium Emissions from Pigment and Stabilizer
Stabilizer Manufacturing - Phase I Technical Report
5, REPORT DATE
June 1988
6. PERFORMING ORGANIZATION CODE
AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS ~
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research' Triangle Park, N.C. 27711
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-02-3817
12. SPONSORING AGENCY NAME AND ADDRESS
DAA for Air Quality Planning and Standards
Office of Air and Radiation
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/200/04
5. SUPPLEMENTARY NOTES
A technical report on cadmium emissions from pigment and stabilizer manufacturing.
Descriptions of these industries and associated air pollution control equipment
are presented. Cadmium emissions as well as health risks from exposure to these
emissions from all plants in the U.S. are discussed.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS C, COSATI 1 leld/G
jfOUp
Air Pollution
Pollution Control
Cadmium Emissions
Pigment Manufacturing
Stabilizer Manufacturing
Air Pollution Control
13B
Unlimited
19 SECUfii i Y CLASS (This Reportl
Unclassified
20 SECURITY CLASS /This page/
Unclassified
21 NO. OF PAGES
20
22. PRICE
EPA Form 2220--1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
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