United States
Environmental Protection
Agency
Industrial Environmental Research EPA 600 2-79-210o
Laboratory December 1979
Cincinnati OH 45268
Reeearch and Development
Status
Assessment of
Toxic Chemicals
Vinylidene Chloride
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution-sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-79-2100
December 1979
STATUS ASSESSMENT OF TOXIC CHEMICALS:
VINYLIDENE CHLORIDE
by
D. R. Tierney
T. R. Blackwood
Monsanto Research Corporation
Dayton, Ohio 45407
and
M. R. Piana
Radian Corporation
Austin, Texas 78766
Contract No. 68-03-2550
Project Officer
David L. Becker
Industrial Pollution Control Division
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental
Research Laboratory - Cincinnati, U.S. Environmental Protection
Agency, and approved for publication. Approval does not signify
that the contents necessarily reflect the views and policies of
the U.S. Environmental Protection Agency, nor does mention of
trade names or commercial products constitute endorsement or
recommendation for use.
11
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FOREWORD
When energy and material resources are extracted, processed,
converted, and used, the related pollutional impacts on our
environment and even on our health often require that new and
increasingly more efficient pollution control methods be used.
The Industrial Environmental Research Laboratory - Cincinnati
(lERL-Ci) assists in developing and demonstrating new and
improved methodologies that will meet these needs both effi-
ciently and economically.
This report contains a status assessment of the air
emissions, water pollution, health effects, and environmental
significance of asbestos. This study was conducted to provide
a better understanding of the distribution and characteristics
of this pollutant. Further information on this subject may be
obtained from the Organic Chemicals and Products Branch,
Industrial Pollution Control Division.
Status assessment reports are used by lERL-Ci to communi-
cate the readily available information on selected substances to
government, industry, and persons having specific needs and
interests. These reports are based primarily on data from open
literature sources, including government reports. They are
indicative rather than exhaustive.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
111
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ABSTRACT
Vinylidene chloride (VDC) is synthesized from ethylene dichloride
with 109 x 103 metric tons produced annually. VDC monomer is used
in the manufacture of barrier coatings, fibers, and plastics. It
is estimated that 1.0 x 103 to 1.8 x 103 metric tons/yr of vinyl-
idene chloride are emitted to the atmosphere from VDC production
and consumption.
Control technology for VDC production includes activated carbon
adsorption, refrigerated solvent scrubbing, incineration, and
vent recovery systems. Technology effective in controlling
vinyl chloride emissions is applicable to VDC; industry is
therefore adopting similar controls.
Exposure to vinylidene chloride may cause adverse effects to the
central nervous system and liver functions of humans. Recent
studies have indicated that a high percentage of workers exposed
to chronic levels of VDC have shown a substantial loss in liver
function. NIOSH is planning to evaluate further studies to
determine what workplace standards should be adopted.
The quantity and composition of organic pollutants from plants
where VDC is produced or consumed was not available for this
report. Quantitative analysis and assessment of pollutants from
plants where VDC is used needs to be accomplished to determine
the potential health hazards of VDC production and consumption
to surrounding populations.
This report was submitted in partial fulfillment of Contract
68-02-2550 by Monsanto Research Corporation under the sponsorship
of the U.S. Environmental Protection Agency. This report covers
the period November 1, 1977 to December 31, 1977. The work was
completed as of January 20, 1978.
IV
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CONTENTS
Foreword iii
Abstract iv
Figures vi
Tables ..... vi
Conversion Factors and Metric Prefixes vii
Acknowledgement viii
1. Introduction. . . . - 1
2. Summary 2
3. Source Description 5
Chemical and physical properties 5
Production 6
Process description 7
Uses 8
4. Environmental Significance and Health Effects .... 12
Environmental significance 12
Health effects 16
5. Control Technology 19
Workspace environment 19
VDC recovery 19
Organic waste incineration 19
Storage tank emissions 20
Current-industry efforts 20
6. Regulatory Actions in Progress 22
References 23
v
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FIGURES
Number Page
1 Flow diagram showing the production and
purification of vinylidene chloride 8
2 Geographic distribution of plants that process
vinylidene chloride 11
3 Saran emulsion process 14
4 Saran suspension process 14
TABLES
1 Vinylidene Chloride 3
2 Chemical and Physical Properties of VDC 5
3 Typical Analysis of VDC 6
4 Atmospheric Reactivity of VDC to Atmospheric Radicals . 6
5 VDC Production LocationxS (1974) 7
6 Consumption and End Use of Vinylidene Chloride (1974) . 10
7 Estimated.Annual Emissions of Vinylidene Chloride
in the United States 15
8 Estimated Population Around VDC Plants 16
9 Acute Toxicity of Vinylidene Chloride 18
VI
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CONVERSION FACTORS AND METRIC PREFIXES3
CONVERSION FACTORS
To convert from to Multiply by
Degree Celsius (°C) Degree Fahrenheit t° = 1.8 t° + 32
Kilogram (kg) Pound-mass (pound-mass
avoirdupois) 2.204
Kilometer2 (km2) Mile2 3.860 x 10"1
Meter3 (m3) Foot3 3.531 x 10l
Meter3 (m3) Gallon (U.S. liquid) 2.642 x 102
Metric ton Pound-mass 2.205 x 103
Pascal (Pa) Pound-force/inch2 (psi) 1.450 x lO"4
METRIC PREFIXES
Prefix Symbol Multiplication factor Example
Kilo k 103 1 kg = 1 x 103 grams
Milli m 10~3 1 mm = 1 x 10~3 meter
Standard for Metric Practice. ANSI/ASTM Designation:
E 380-76% IEEE Std 268-1976, American Society for Testing and
Materials, Philadelphia, Pennsylvania, February 1976. 37 pp.
vii
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ACKNOWLEDGEENT
This report was assembled for EPA by Radian Corporation, Austin,
TX, and Monsanto Research Corporation, Dayton, OH. Mr. D. L.
Becker served as EPA Project Officer, and Dr. C. E. Prank, EPA
Consultant, was principal advisor and reviewer.
Vlll
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SECTION 1
INTRODUCTION
Vinylidene chloride (VDC) is an important monomer in the manu-
facture of methyl chloroform, saran, and other plastics. In
January, 1976, The National Institute of Occupational Safety and
Health (NIOSH) reported that about 60% of workers examined in a
New Jersey plant using VDC had developed liver disorders and
announced its intention to investigate the situation. Previous
laboratory animal studies had suggested that VDC might be a
liver carcinogen and might produce a number of other adverse
health effects.
This report briefly describes the production and environmental
release of VDC. Potential human exposure and health effects due
to VDC exposure are also given. Present and future control tech-
nology for VDC emissions are explained along with government
regulatory actions.
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SECTION 2
SUMMARY
The manufacture of vinylidene chloride (VDC) is commercially
significant, with an annual production level of 109 x 103 metric
tons3. End uses of vinylidene chloride include polymerization of
the monomer to form barrier resins used in film coating and the
fabrication of various packaging materials. Approximately 80%
of the vinylidene chloride produced is used captively to produce
1,1,1-trichloroethane or in polymer synthesis.
Emissions of VDC adversely affect humans. Exposure to VDC
causes central nervous system depression, skin and eye irrita-
tion, and altered liver function. VDC is also a suspected
carcinogen. It has been estimated that 1.0 x 103 to 1.8 x 103
metric tons/yr of vinylidene chloride are emitted to the atmos-
phere from VDC synthesis and polymerization and from polymer
fabrication. Within a 5-mile radius of all plants where VDC is
produced or used, there are 3.6 million persons Who may be ex-
posed to VDC emissions.
Control technology for VDC emissions during production include
activated carbon adsorbers, refrigerated solvent scrubbing
systems and incinerators. Storage tank emissions are controlled
by refrigerated vent recovery systems or return venting to main
process streams. Workers at industrial sites where VDC is made
or used have the greatest risk from exposure. Careful plant
maintenance and handling procedures are mandatory precautions
to ensure a reasonably safe work environment.
A workplace standard may be recommended by the National Institute
of Occupational Safety and Health (NIOSH). Preliminary studies
have indicated that VDC regulation under the Clean Air Act is not
warranted at this time.
Table 1 summarizes major points of information given in the
report on production, transportation, and uses of VDC.
1 metric ton = 106 grams; conversion factors and metric system
prefixes are presented in the prefatory pages of this report.
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TABLE 1. VINYLIDENE CHLORIDE
Extent of problem
Emission source
Emission quantity,
metric tons/yr
Population exposed,
persons
Control method
Regulatory action
U)
Production:
From ethylene dichloride
1.5 x 103
89,000
Transportation:
Vehicle loading and cleaning
Industrial use:
0.3 x 103a
_b
Carbon adsorbers, refrigerated
solvent scrubbing, incinera-
tion, refrigerated vent
recovery systems, controls
similar to vinyl chloride
control.
Purge lines to carbon adsorp-
tion unit or incinerator.
Regulation under Sections 111
and 112 of Clean Air Act not
needed at this time.
TLV - 40 mg/m3.
Designated as a priority pollu-
tant under the Federal Water
Pollution Control Act.
Tank car size has been limited
to 95 m3.
Consumption, 1974
18 x 103 metric tons/yr
polymer i zation
fabrication
0.3 x 103a
_D
_b
3,500.000
_b
_b
_b
_b
Workplace standards
recommended .
may be
Value represents the mass of emissions for both transportation and industrial use.
Information unknown.
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Based on the information provided in this report, the following
items should be considered in future studies:
• Environmental levels of VDC.
• Quantity and composition of emissions from the polymeri-
zation and use of VDC polymers in fabricated products.
• Amount of VDC and related compounds discharged to
waterways.
• The effectiveness and cost of control technology
applicable to VDC production and consumption facilities.
• Chronic effects of prolonged low level exposure to VDC.
Due to the demonstrated toxicity of VDC, it is recommended that
VDC emissions be regulated from plants where VDC is produced or
consumed. Imposed regulations need to be based on health effects
data and pollutant assessments from VDC plants. Acceptable
environmental levels of VDC need to be defined.
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SECTION 3
SOURCE DESCRIPTION
CHEMICAL AND PHYSICAL PROPERTIES
The chemical name for VDC is 1,1-dichloroethylene and its molec-
ular formula is CH2=CC12- The properties of VDC are listed in
Table 2.
TABLE 2. CHEMICAL AND PHYSICAL PROPERTIES OF VDC (1)
Molecular weight: 97.0 Physical state: Volatile liquid
Vapor pressure: 82.28 kPa at 25°C Melting point: -122.53°C
Boiling point: 37°C at 101.33 kPa Solubility: Insoluble (H2O)
Density: 1.213 at 20°C/4°C
The flash point of VDC is about -10°C, but it will not support
combustion. The explosive limit range is 7 to 16 volume percent
in room temperature air.
VDC polymerizes spontaneously within 48 hours of production.
If it is stored, small amounts of polymerization inhibitors
(hydroquinone, alkylamines, or organic sulfur derivatives) are
added (2). If VDC is stored in the presence of air or oxygen
without an inhibitor at temperatures in fene range of -40°C to
+25"C, the oxygen dissolves and reacts quickly to form a per-
oxide compound. The peroxide compound is violently explosive.
It is adsorbed on the polymer and any separation (i.e., degrada-
tion) of this polymer will result in an explosive compound. A
slight mechanical shock or heat will detonate a dry compound
containing more than 15% of the peroxide (1). A typical analysis
of commercial grade VDC is shown in Table 3.
(1) Kirk-Othmer Encyclopedia of Chemical Technology, Second
Edition, Volume 21. John Wiley and Sons, Inc., New York,
New York, 1970. pp. 275-279.
(2) Hushon, J. and M. Kornreich. Air Pollution Assessment of
Vinylidene Chloride. MTR-7230. U.S. Environmental Protec-
tion Agency, Research Triangle Park, North Carolina, May
1976. 73 pp.
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The slow decomposition of VDC peroxides will produce formalde-
hyde, phosgene, and hydrochloric acid. A sharp acrid odor
probably indicates the presence of peroxides (1). The atmos-
pheric reactivity of VDC is given in Table 4 (3).
TABLE 3. TYPICAL ANALYSIS OF VDC (1)
Constituent, ppma
Vinylidene chloride, wt%
Vinyl chloride
cis-1, 2-dichloroethylene
trans-i, 2-dichloroethylene
1, 1-Dichloroethane
Ethylene dichloride
1,1, 1-Trichloroethane
Trichloroethylene inhibitor
MEHQC grade
Phenol grade, wt%
Value
99.7
850
500
1,500
10
10
150
10
200
0.6 to 0.8
Except where indicated.
Excluding inhibitor.
Monomethyl ether of hydroquinone.
TABLE 4. ATMOSPHERIC REACTIVITY OF VDC
TO ATMOSPHERIC RADICALS (3)
Activity towards
radical Half life
Ozone <1 day
Ketone >1,000 days
Hydroxyl <1 day, producing phosgene
and formaldehyde
PRODUCTION
Vinylidene chloride is produced at three locations with a total
estimated production of 109 x 103 metric tons/yr. Table 5
identifies manufacturers and estimated production levels.
The chlorination of ethylene dichloride produces 1,1,2-trichloro-
ethane and it is estimated that the use of ethylene dichloride
(3) Dorigan J. Scoring of Organic Air Pollutants: Chemistry,
Production, and Toxicity of Selected Synthetic Organic
Chemicals. Mitre Corporation, September, 1976.
-------
for the production of VDC will increase at an average annual
rate of 7% from 1974 to 1979. It is also estimated that the
consumption of methyl chloroform, used in the other VDC produc-
tion method, will not change over this time period.
TABLE 5. VDC PRODUCTION LOCATIONS (1974)
Production,
Producer Location 10 3 metric tons/yr
Dow Chemical, Co. Freeport, TX 64a
Plaquemine, LA
PPG Industries, Inc. Lake Charles, LA 45
TOTAL 109
Dow was planning to expand plant capacity during 1975.
Approximately 32 x 103 metric tons (70%) of this VDC
production were used to manufacture 1,1,1-trichloroethane.
PROCESS DESCRIPTION
Vinylidene chloride (VDC) is made from ethylene dichloride.
Intermediates may be 1,1,1-trichloroethane (methyl chloroform) or
1,1,2-trichloroethane. In addition, VDC is used to manufacture
methyl chloroform only when the VDC has been produced from
1,1,2-trichloroethane. The actual amount of VDC produced and
consumed is unknown; however, 77 x 103 metric tons is ultimately
produced. An additional 32 x 103 metric tons is estimated to be
formed as an intermediate to methyl chloroform. The reversible
reaction for the formation of VDC from methyl chloroform is (4):
CH3CC13 > CH2=CC12 + HC1 (1)
methyl vinylidene hydrochloric
chloroform chloride acid
VDC is also made by dehydrochlorinating 1,1,2-trichloroethane
with lime or aqueous sodium hydroxide, as shown in Equation 2 (4).
CH2C1CHC12 + NaOH »- CH2=CC12 + NaCl + H20 (2)
1,1,2-trichloroethane + sodium VDC + sodium + water
hydroxide chloride
This reaction takes place at approximately 70°C in a long cylin-
drical reaction vessel. The crude product is separated by dis-
tillation under a nitrogen atmosphere. A phenolic inhibitor is
(4) Sherwood, P. W. Raw Materials for Plastics and Resins.
Industrial and Engineering Chemistry, 54(12) :30, 1962.
-------
generally added to the distilled product. Product VDC 'is puri-
fied by washing with ferrous sulfate and caustic soda solution.
After washing, inhibited vinylidene chloride is dried by azeo-
tropic distillation and sent to a finishing column where purified
vinylidene chloride is withdrawn and stored. More inhibitor may
be added prior to storage (2). Figure 1 is a flow diagram showing
the production and purification of vinylidene chloride (2, 5).
INHIBITOR
WASTE WATER
1,1,2-TRICHLOROETHANE
FINISHED VINYLIDENE
CHLORIDE TO STORAGE I
RECYCLE 1,1,2 - TRICHLOROETHANE
•PURGE
Figure 1. Flow diagram showing the production and puri-
fication of vinylidene chloride (2, 5).
Vinyl and Diene Monomers, Copyright (C) 1971.
Reprinted by permission of John Wiley & Sons, Inc.
USES
It is estimated that 70% of the VDC produced by PPG Industries is
used captively to make 1,1,1-trichloroethane. Dow Chemical also
captively uses about 78% of its VDC in polymer synthesis (6).
The remaining VDC (18 x 103 metric tons/yr) is marketed to a
variety of secondary users.
(5) Shelton, L. G., D. E. Hamilton and R. H. Fisackerly. Vinyl
and Vinylidene Chloride. In: Vinyl and Diene Monomers,
Part 3, Volume 24. E. C. Leonard, ed. Wiley, Interscience,
New York, New York, 1971. pp. 1205-1282.
(6) Landau, E., and N. E. Manos. Epidemiology Studies, Task IV
Vinylidene Chloride. EPA-560/6-76-022, U.S. Environmental
Protection Agency, Washington, D.C., August 1976. 128 pp.
8
-------
VDC is consumed in the production of films/ fibers, plastics, and
paper coatings (7). The manufacture of polyvinylidene copolymers
is the major use of VDC. The extruded films of the copolymers
are used in packaging and have excellent resistance to water
vapor and most gases (1). The chief copolymer is Saran (poly-
vinylidene chloride/vinyl chloride), a transparent film used for
food packaging. The films shrink when exposed to higher than
normal temperatures. This characteristic is advantageous in the
heat-shrinking of overwraps on packaged goods and in the sealing
of the wraps (1). Recent growth in the production of shrinkable
bags from the VDC copolymer, vinyl chloride/VDC/vinyl chloride,
has been noted. These bags are used in the meat packaging
industry.
VDC has a wide application as a barrier coating for paper and
plastic films. Saran latexes have been developed which form an
extremely water-resistant coating. This coating also provides
the heat-seal characteristics of Saran. Other applications of
these latexes include mixing in cement to produce high-strength
mortars and concretes, and as binders for paints and nonwoven
fabrics providing both water resistance and nonflammability (1).
VDC polymer lacquers are also used in coating films and paper.
The lacquers are used mainly in food packaging where the features
of inertness, lack of odor or taste, and nontoxicity are needed.
The lacquers have also been applied as interior coatings for ship
tanks, railroad tank cars, fuel storage tanks, and for the coat-
ing of steel piles and structures. The chemical resistance and
good adhesion of the lacquers have made them an excellent long-
term coating. The adhesive property also makes the lacquers a
good binder for oxide pigmented coatings of magnetic tapes (1).
VDC is used to produce fibers. Monofilaments, made by extruding
the copolymer, are used in the textile industry as furniture and
automobile upholstery, drapery fabric, outdoor furniture,
venetian-blind tape, and filter cloths (1). VDC is also used as
a comonomer in the production of some modacrylic fibers such as
Eastman Chemicals' Verel® and Monsanto's SEF® (1).
VDC copolymer plastics are produced by molding and extrusion of
copolymer resins. The products provide chemical resistance and
long service life. Uses of the plastics include gasoline fil-
ters, valves, pipe fittings, containers, chemical process equip-
ment, tubing, and pipe liners (1).
Table 6 lists companies utilizing VDC for various ends (6). The
total amount of VDC available for these uses is 18 x 103 metric
tons/yr. Plant locations where vinylidene chloride is processed
are shown in Figure 2.
(7) Chemical Origins and Markets, Fifth Edition. G. M. Lawler,
ed. Chemical Information Services, Menlo Park, California,
1977. 118 pp.
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TABLE 6. CONSUMPTION AND END USE OF VINYLIDENE CHLORIDE (1974) (6)
Product
PVDC3 latex
PVDC latex
PVDC synthetic fibers
PVDC-coated cellophane
Extruded PVDC products
Company
Dewey and Almy Chemical
Morton Chemical Co.
BASF - Wyandotte
Staley Chemical
Dow Chemical
Olin
DuPont
Dow Chemical
Goodrich chemical
Rohm and Haas
Standard Brands Chemical Industries
National Starch and Chemical Corp.
Tennessee Eastman
Monsanto Co.
American Cyanamid
DuPont
Olin
FMC
Cryovac
Oscar Meyer
Dow Chemical
American Can Co.
Amtech, Inc.
Onion Carbide Corp.
Location
Owensboro, KV
Ringwood , IL
South Keamy, NJ
Lemont , IL
Midland, MI
Pisgah Forest, NC
Circleville, OH
Midland, MI
Allans Point, CT
Dal ton, GA
Freeport, TX
Avon Lake, OH
Knoxville, TN
Bristol, PA
Cheswold, DE
Kensington, GA
Merdosia, IL
Kingsport, TN
Decatur, AL
Pensacola, FL
Richmond , VA
Clinton, IA
Tecumseh, KS
Pisgah Forest, NC
Covington , IN
Fredricksburg, VA
Marcus Hooks, PA
Simpsonville, SC
Cedar Rapids, IA
Camarillo, CA
Iowa Park, TX
Madison, WI
Chicago, IL
Davenport, IA
Philadelphia, PA
Nashville, TN
Vernon, CA
Midland, HI
Cleveland, OH
Odenton, MD
Centerville, IA
Capacity,
metric tons/yr
4,500
1,600
830
830
830
200
200
TOTAL 8,990
6,800
_b
TOTAL 13,600
TOTAL
TOTAL
TOTAL 20,000
Amount of
vinylidene chloride
monomer used,
metric tons/yr
4,000
1,400
750
750
750
180
180
8,010
3,400
6,800
2,000
-
-
End use
Barrier coatings {coatings for
glassines, paper, paperboard,
polypropylene , and polyester
film)
Miscellaneous applications
Fabrication
Fabrication
Fabrication
Polyvinylidene chloride.
Dashes indicate data unknown.
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Figure 2. Geographic distribution of plants that process vinylidene chloride.
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SECTION 4
ENVIRONMENTAL SIGNIFICANCE AND HEALTH EFFECTS
ENVIRONMENTAL SIGNIFICANCE
Emissions arise during the production, use, and transportation of
VDC. One estimate indicates that 1.8 x 103 metric tons of VDC
were lost to the air in 1974 (2). A more recent publication
states that 1 x 103 metric tons are released per year (3).
VDC Emissions During Production
Process points where VDC emissions occur include vents from the
separator, finishing column, recycling tower, and storage tanks.
VDC can be emitted from process wastewater and fugitive sources.
Air from process vents may contain up to 5% VDC monomer. Possi-
ble fugitive and wastewater sources include 1) loading, unload-
ing, and storage of VDC; 2) leaks from pumps, compressors,
valves, and agitators; 3) pipe and equipment flanges and manhole
cover seals; 4) opening equipment for inspection and maintenance;
5) sampling for laboratory analysis; 6) VDC in process water
exposed to atmosphere; and 7) manual venting of equipment (2).
It has been estimated that 1.5 x 103 metric tons of VDC are
emitted annually during production, principally through purifi-
cation and recycle vents. This estimate, however, assumes there
is no use of control technology, and therefore should be con-
sidered as an upper bound (2).
The heavy ends, composed of phenolic inhibitor and unreacted
1,1,2-trichloroethane, are removed from the finishing column and
processed through a recycle tower (2). Phenolic inhibitor and
1,1,2-trichloroethane are drawn off and recycled while tower
bottoms are disposed of as waste. Wastewater streams are dis-
charged from the reactor, separator, and recycling tower (2).
Effluent streams are also produced during tank car and storage
tank washings.
Product Storage and Transportation
Vinylidene chloride is stored in the absence of light at -10°C
and 69 kPa (2). Storage tanks are lined with nickel, baked
phenolic, or glass, since the monomer may be corrosive or
12
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unstable when contacted with steel (2). A layer of nitrogen is
placed over the monomer to prevent contact with air or water
which may cause undesirable polymerization.
Vinylidene chloride is transported by tank cars, tank trucks and
barges (2). Jumbo tank cars, having 76 m3 capacities, are the
most common means of transport.
Pollution Potential from VDC Consumption and Use
PPG Industries, Inc., hydrochlorinates VDC to produce methyl
chloroform. The reaction is represented as (8):
CH2=CC12 + HC1 -> CH3CC13
This reaction is ideally conducted in the liquid phase with a
catalyst such as ferric chloride. The reaction is carried out at
25°C to 30°C under slightly superatmospheric pressure. The pro-
duct is continuously removed from the hydrochlorination step and
is purified by fractional distillation, then dried, and stabi-
lizers added to make it suitable for commercial use (8). Poten-
tial sources of gaseous VDC emissions exist throughout the
process. Wastewater streams are also produced which may contain
VDC and other materials.
The polymerization of VDC is another source of emissions. Both
emulsion and suspension addition polymerization processes are
used to produce polyvinylidene chloride latex and resin.
Figures 3 and 4 give block diagrams for Saran resin production by
the emulsion and suspension processes. VDC emissions arise at
all steps of the polymerization. In both processes, the VDC
monomer is washed to remove the inhibitor. During the reaction,
the material is agitated. When the reaction is complete, the
residual monomer is removed by flashing in vertical tanks and
steam stripping in single or multiple stages. Fugitive emissions
of the monomer may occur from leaks in equipment, agitators,
vents, valves, and rupture discs. A liquid waste stream results
from water-washing of the monomer feedstock to remove the
inhibitor. The wastewater loading for polyvinylidene chloride
is estimated to be 4.2 m3/metric ton product. Additional liquid
waste may result from leaks in the equipment. Another source of
emissions is the cleaning of the reactors, accomplished by
removal of solid deposits or by washing down the side with
solvent or high-pressure steam (2).
In the drying stage of these processes, gaseous emissions of
VDC and other low boiling compounds may result. Wastewater is
produced from the dryers containing VDC and chemical additives.
(8) Faith, Keyes, and Clark's Industrial Chemicals, Fourth
Edition. F. A. Lowenheim and M. K. Movan, eds. John Wiley
and Sons, New York, New York, 1975. pp. 837-838.
13
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VENT
VENT
MONOMER STORAGE
AND PURIFICATION
POLYMERIZATION
-VENT
MONOMER
RECOVERY
•VENT
Figure 3. Saran emulsion process (2).
VENT
VENT
Figure 4. Saran suspension process (2)
14
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In the suspension addition process, contaminated wastewater
streams are produced from the centrifugation and filtration oper-
ations. Particulate emissions may arise from dusting in the
dryers. In the final product preparation using suspension addi-
tion polymerization, the devolatilization procedure may cause
gaseous emissions of VDC. Particulates may be emitted from
pelletizing and bagging. Also, the extrusion of the polymer may
produce a wastewater stream from quenching (2). There are no
estimates of the levels of unreacted monomer emitted in the
polymerization process. However, one EPA report estimates that
as much as 25% of the VDC used in any given Saran production run
is disposed of in landfill mainly in polymerized form (2).
Table 7 summarizes the estimated annual emissions of VDC from
various sources in the United States.
TABLE 7. ESTIMATED ANNUAL EMISSIONS OF VINYLIDENE
CHLORIDE IN THE UNITED STATES (2)
VDC emissions,
Source metric tons/yr
Monomer synthesis l,500h
280
Polymer synthesis:
Latex for burner coatings 54
Latex for miscellaneous coatings 68
Synthetic fibres 73
Coating resin for cellophane 82
Extrusion resin (emulsion) 12
Extrusion resin (suspension) 18
TOTAL 308
Fabrication polymer processing:
Coating cellophane , 0.7
Coating plastics, paper and glassine 7.4
Extrusion °-2
Miscellaneous coating
TOTAL 14
Q
TOTAL 1,840
Emissions using an existing control technology.
bEmissions reflecting new control technology at PPG
plant by late 1975.
CTotal of uncontrolled emissions.
15
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Population at Risk
Worker exposure has generally not been monitored in the past.
Tests have shown that 20,000 ppm can easily be reached in the
proximity of a spill. In some cases, past worker exposures to
VDC may have exceeded those of vinyl chloride, which were
measured at 300 ppm to 1,000 ppm before OSHA limits were imposed
(6) .
To estimate the number of persons who may be exposed to VDC emis-
sions, the population in a 5-mile radius around each plant listed
in Table 6 and Table 5 has been determined (6). Approximately
3.5 million persons reside within this area near plants which
either synthesize or polymerize VDC and/or fabricate materials
based on VDC (Table 8) (6).
TABLE 8. ESTIMATED POPULATION AROUND VDC PLANTS (6)
Number of
Process persons
Monomer synthesis 89,000
Polymer synthesis 605,000
Fabrication 2,880,000
TOTAL 3,574,000
HEALTH EFFECTS
Exposure to either vapor or liquid VDC may be harmful. VDC has a
moderate vapor toxicity (9). The exposure to high vapor concen-
trations of VDC results mainly in central nervous system depres-
sion and the associated symptoms of drunkenness. VDC has a
characteristic mild, sweet odor resembling carbon tetrachloride
or chloroform. A definite odor can be detected by most people
at 1,000 ppm in air although some people detect the odor at
500 ppm. A disagreeable odor can be detected in vapors contain-
ing decomposition products at less than 500 ppm (9).
The odor or irritating property is usually inadequate to warn of
overexposure. A drunkenness is rapidly produced with a single
exposure of a few minutes to a high concentration of VDC (in the
order of 4,000 ppm). Continued exposure at this concentration
(9) Irish, D. C. Aliphatic Halogenated Hydrocarbons. In:
Industrial Hygiene and Toxicology, D. W. Fassett and D. D.
Irish, Eds. Interscience Publishers, New York, New York,
1962. pp. 1305-1307.
16
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may cause unconsciousness. Prompt and complete recovery from
the anesthetic effects is usually observed if the exposure is
of short duration. Prolonged exposure or repeated short-term
exposures may be dangerous even if the vapor concentrations are
too low to cause drunkenness. Organic injury may occur to the
kidneys and liver. It has been recommended that the vapor con-
centration of VDC be below a time-weighted average of 25 ppm for
repeated exposures (8 hr/day, 5 days/wk). Injury should not
result from a single exposure of about 1,000 ppm for up to one
hour or 200 ppm for up to eight hours (1).
Liquid VDC is irritating to the skin and eyes. Skin irritation
has been noted after only a few minutes of contact; prolonged
contact can cause first degree burns (2). This irritation may be
partially due to the inhibitor (MEHQ or phenol) used in VDC to
prevent polymerization.
Injury from skin absorption of the amount of phenol used in
inhibited VDC appears to be unlikely. Inhibited VDC is moder-
ately irritating to the eyes and will cause pain and conjunctival
irritation and, possibly, some transient corneal injury and
iritis (2).
VDC has recently been reported to cause liver impairment. At
the BASF Wyandotte VDC polymerization plant in South Kearny,
New Jersey, 27 of 46 workers examined showed 50% or greater loss
in liver function. Other examinations indicate that VDC is
biochemically altered in the body and may form intermediates
similar to the cancer-producing metabolites of vinyl chloride
(10).
VDC is a suspected carcinogen (3). Inhaled VDC is reported to
produce liver tumors in rats at 200 ppm. Inhalation experiments
with animals showed that VDC causes liver and kidney damage.
When rats were pre-exposed to vinyl chloride and then tested with
VDC, the acute toxicity of VDC was greatly enhanced. Concurrent
exposure with vinyl chloride reduces the acute effects and may
potentiate the carcinogenic effects. This is important because
a significant part of polymer production involves the use of
both chemicals (2). Acute toxicity data is given in Table 9.
(10) Summary Characteristics of Selected Chemicals of Near-Term
Interest. EPA-560/4-76-004 (PB-253 817), U.S. Environmental
Protection Agency, Washington, D.C., April 1976. 50 pp.
17
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TABLE 9. ACUTE TOXICITY OF VINYLIDENE CHLORIDE (3)
Lowest toxicitya
Lethal dose
Lethal concentration
Dosage
3,700 mg/kg
5,750 mg/kg
225 mg/kg
10,000 ppm
Animal
Rabbit
Dog
Dog
Rat
Route
Subcutaneous
Oral
Intravenous
Inhalation
a
Known to cause death.
18
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SECTION 5
CONTROL TECHNOLOGY
WORKSPACE ENVIRONMENT
Vinylidene chloride is a toxic and volatile chemical requiring
careful handling and storage during its synthesis or polymeriza-
tion. To avoid worker exposure to VDC, spills should be cleaned
up immediately, equipment periodically inspected, and leaks
repaired (11).
There are no specific government regulations concerning VDC
emissions from monomer synthesis or processing. Several methods
are available, however, to control vinylidene chloride emissions
during monomer production, storage, and transportation. The ef-
ficiencies and costs of the control methods described were not
available for this report.
PROCESS VENTS
Vents are located on the separator, finishing columns, recycling
tower, and storage tanks of a VDC production facility (2). VDC
emissions are ducted from the vents to activated carbon adsorbers
where VDC is removed. Industry has not found it economically
feasible to regenerate spent carbon thus requiring its disposal
as a waste product.
VDC RECOVERY
Vinylidene chloride can be recovered from gas purging operations
by refrigerated solvent scrubbing (2). Solvents which have been
used for this control technique are acetone, methyl ethyl ketone,
ethylene dichloride, butyl acetate and heptyl butyl ketone.
Recovered vinylidene chloride is returned to the process system
while the purge gases are being cleaned of VDC.
ORGANIC. WASTE INCINERATION
Incinerators are generally used to dispose of flammable liquid
wastes produced during VDC synthesis (2). Process air streams
(11) Vinylidene Chloride Monomer, Physical Properties and Han-
dling Precautions. Dow Chemical Company, Coatings Technical
Service, Midland, Michigan.
19
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may be vented to the incinerator to control hydrocarbon
emissions.
STORAGE TANK EMISSIONS
Emissions from storage tanks may be controlled by other refrig-
erated vent recovery systems or by venting storage tank emissions
to the main process stream. Vinylidene chloride is then recov-
ered and the inerts are removed along with production wastes (2).
»
CURRENT INDUSTRY EFFORTS
The VDC industry is adopting control procedures for vinylidene
chloride which parallel those for vinyl chloride (2). The type
of control technology used in controlling vinyl chloride emis-
sions could be applicable to VDC. Suggested control measures
for VDC from existing vinyl chloride technology are given in the
following paragraphs.
The emissions from pump, compressor, and agitator seals can be
controlled by installing double mechanical seals and maintaining
a liquid between the seals at sufficient pressure to cause the
liquid to leak into the pump should the seal fail.
VDC that is present in equipment that is to be opened for main-
tenance or inspection can be vented to a control device by
purging the equipment with an inert gas such as nitrogen or
displacing the contents with water before it is opened.
The emissions occurring during loading and unloading from the
loading area lines can be controlled by purging the lines to a
control device such as an incinerator or carbon adsorption unit.
The emissions from slip gauges can also be vented to a control
device.
Emissions from leaking pressure relief valves can be reduced by
installing leak proof rupture discs upstream of the relief
valve.
Emissions resulting from sampling for laboratory analysis can be
virtually eliminated by letting the gas that is to be sampled
flow through the sample flask to a lower pressure point in the
process. The sample flask can then be blocked off and any VDC
that remains in the sample lines can be purged to a control
device before the sample flask is removed.
Many fugitive sources can be monitored with a formal program of
leak detection and repair. The detection can be accomplished
with both fixed point and portable monitoring devices. Using
methods described above, fugitive emissions could be reduced
by 90%.
20
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VDC can be stripped from the inprocess wastewater, and transfer-
red to a control device, such as an incinerator or adsorber; VDC
could possibly be recovered from the adsorber.
VDC that is present in the polymerization reactors can be dis-
placed to the monomer recovery system for reuse by filling the
reactor with water before it is opened for cleaning, maintenance,
or inspection.
The need to open the reactors for cleaning can be reduced by
cleaning the reactor while it is closed with high pressure water
sprays, circulating an organic solvent through the reactor to
dissolve any solids that may have accumulated and by a combina-
tion of recipe reformulation and reactor design to reduce scale
formation.
Polymerization reactor safety valve discharges can be avoided
by instrumenting each reactor with a pressure or temperature
alarm to alert the operator to take appropriate action. This
could include venting the reactor contents to a gasholder where
the VDC can be recycled, or injecting certain chemicals into the
reactor to stop the reaction and prevent further pressure build-
up. During power failure, these chemicals could be added manu-
ally by hydraulic injection systems.
VDC that is present in all captive or point sources in the
monomer and polymer plants can be controlled by adsorption on
activated carbon, by absorption in an organic solvent, or by
incineration. For vinyl chloride, each of these techniques can
reduce the vinyl chloride content of the gas being treated to
less than 10 ppm.
Control levels equivalent to the "add-on" devices discussed
above can be achieved in certain point sources in the polymeriza-
tion process by stripping the slurry leaving the reactors of the
residual, unreacted VDC. These sources, which are downstream
of the stripper, include the slurry blend tanks, the centrifuges,
the dryers, and the bulk resin storage areas.
i
It is difficult to estimate the emissions reduction and costs of
these control strategies as applied to VDC. Control test data
and cost estimates for vinyl chloride are available in EPA's
publication on the Emission Standard for Vinyl Chloride (12).
(12) Standard Support and Environmental Impact Statement: Emis-
sion Standard for Vinyl Chloride. EPA-450/2-75-009, U.S.
Environmental Protection Agency, 1975. 536 pp.
21
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SECTION 6
REGULATORY ACTIONS IN PROGRESS
The American Conference of Governmental Industrial Hygienists has
established a threshold limit value of 10 ppm (13). Vinylidene
chloride has recently been reported to cause liver impairment.
Workers examined at the BASF Wyandotte VDC polymerization plant
in South Kearny, New Jersey showed a 50% or greater loss in liver
function. Other studies have indicated that VDC is biochemically
altered in the body and may form intermediates similar to the
cancer-producing metabolites of vinyl chloride (10).
NIOSH is planning to monitor the follow-up studies on workers at
the South Kearny BASF plant and will survey other VDC production
sites in 1977 to determine if a workplace standard should be
recommended (10).
EPA is preparing an assessment of the air pollution problems
associated with VDC production and use. Fetotoxicity and embryo-
toxicity have been demonstrated under EPA-funded contracts. Data
on environmental effects of VDC are also being obtained (10).
A preliminary air pollution assessment of VDC indicates that
regulation under Sections 111 and 112 of the Clean Air Act is
not warranted at this time (14). VDC has been designated as a
priority pollutant for study under the Federal Water Pollution
Control Act.
(13) TLV's® Threshold Limit Values for Chemical Substances and
Physical Agents in the Workroom Environment with Intended
Changes for 1975. American Conference of Governmental
Industrial Hygienists. Cincinnati, Ohio, 1975. 97 pp.
(14) Identification of Selected Federal Activities Directed to
Chemicals of Near-term Concern. EPA-560/4-76-006, U.S.
Environmental Protection Agency, Washington, D.C., July
1976. 36 pp.
22
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REFERENCES
1. Kirk-Othmer Encyclopedia of Chemical Technology, Second
Edition, Volume 21. John Wiley and Sons, Inc., New York,
New York, 1970. pp. 275-279.
2. Hushon, J. and M. Kornreich. Air Pollution Assessment of
Vinylidene Chloride. MTR-7230. U.S. Environmental Protec-
tion Agency, Research Triangle Park, North Carolina,
May 1976. 73 pp.
3. Dorigan J. Scoring of Organic Air Pollutants: Chemistry,
Production, and Toxicity of Selected Synthetic Organic
Chemicals. Mitre Corporation, September 1976.
4. Sherwood, P. W. Raw Materials for Plastics and Resins.
Industrial and Engineering Chemistry, 54(12):30, 1962.
5. Shelton, L. G., D. E. Hamilton and R. H. Fisackerly. Vinyl
and Vinylidene Chloride. In: Vinyl and Diene Monomers,
Part 3, Volume 24. E. C. Leonard, ed. Wiley, Interscience,
New York, New York, 1971. pp. 1205-1282.
6. Landau, E., and N. E. Manos. Epidemiology Studies, Task IV
Vinylidene Chloride. EPA-560/6-76-022, U.S. Environmental
Protection Agency, Washington, D.C., August 1976. 128 pp.
7. Chemical Origins and Markets, Fifth Edition. G. M. Lawler,
ed. Chemical Information Services, Menlo Park, California,
1977. 118 pp.
8. Faith, Keyes, and Clark's Industrial Chemicals, Fourth
Edition. F. A. Lowenheim and M. K. Movan, eds. John Wiley
and Sons, New York, New York, 1975. pp 837-838.
9. Irish, D. D. Aliphatic Halogenated Hydrocarbons. In:
Industrial Hygiene and Toxicology, D. W. Fassett and D. D.
Irish, Eds. Interscience Publishers, New York, New York,
1962. pp. 1305-1307.
10. Summary Characteristics of Selected Chemicals of Near-Term
Interest. EPA-560/4-76-004 (PB-253 817), U.S. Environmental
Protection Agency, Washington, D.C., April 1976. 50 pp.
23
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11. Vinylidene Chloride Monomer, Physical Properties and
Handling Precautions. Dow Chemical Company, Coatings Tech-
nical Service, Midland, Michigan.
12. Standard Support and Environmental Impact Statement: Emis-
sion Standard for Vinyl Chloride. EPA-450/2-75-009. U.S.
Environmental Protection Agency, 1975. 536 pp.
13. TLV's® Threshold Limit Values for Chemical Substances and
Physical Agents in the Workroom Environment with Intended
Changes for 1975. American Conference of Governmental Indus-
trial Hygienists. Cincinnati, Ohio, 1975. 97 pp.
14. Identification of Selected Federal Activities Directed to
Chemicals of Near-term Concern. EPA-560/4-76-006, U.S.
Environmental Protection Agency, Washington, D.C., July 1976.
36 pp.
24
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TECHNICAL REPORT DATA
(riease read Instructions on the reverse before completing)
REPORT NO.
EPA-600/2-79-2100
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
Status Assessment of Toxic Chemicals:
Vinylidene
Chloride
5. REPORT DATE
December 1979 issuing date
6. PERFORMING ORGANIZATION CODE
AUTHOR(S)
T.R. Blackwood, D.R. Tierney
M.R. Piana
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Monsanto Research Corp Radian Corp
1515 Nichols Road 8500 Shoal Creek Blvd
Dayton, Ohio ^07 P.O. Box 99^8
Austin, Texas 78766
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-03-2550
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research La"b«
Office of Research and Development
U.S. Environmental Protection Agency
Cinr-lnnat.T . Ohio
- Cinn, OH
13. TYPE OF REPORT AND PERIOD COVERED
Task Final 11/77 - 12/77
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
lERL-Ci project leader for this report is Dr. Charles Frank,
16. ABSTRACT
This report details the uses and the technology employed to control
emissions of vinylidene chloride. Data on vinylidene chloride
emissions and their sources are given, as well as information dealing
with the effects of exposure to vinylidene chloride. Finally, regula-
tory actions and areas requiring further study are outlined.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
COS AT I Field/Group
Vinylidene Chloride copolymers, Vinylidene
Chloride resins, Polyvinylidene Chloride,
Saran®, Vinylidene resins, Addition resins,
Thermoplastic resins, vinyl resins
Ethylene dichloride
68A
68G
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
33
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
ft U.S. GOVERNMENT PRINTING OFFICE: 1980 -657-146/5514
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