c/EPA
             United States
             Environmental Protection
             Agency
              Industrial Environmental Research  EPA-600/2-79-210m
              Laboratory           December 1979 ...
              Cincinnati OH 45268              Vi '
             Research and Development
Status
Assessment of
Toxic  Chemicals
            \
             Trichloroethylene

-------
                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.

-------
                                     EPA-600/2-79-210m
                                     December 1979
    STATUS ASSESSMENT OF TOXIC CHEMICALS:

              TRICHLOROETHYLENE
                     by
                J. C. Ochsner
               T. R. Blackwood
        Monsanto Research Corporation
             Dayton, Ohio  45407

                     and

              W. C. Micheletti
             Radian Corporation
            Austin, Texas  78766
           Contract No. 68-03-2550
               Project Officer

               David L. Becker
    Industrial Pollution Control Dvision
Industrial Environmental Research Laboratory
           Cincinnati, Ohio  45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
     OFFICE OF RESEARCH AND DEVELOPMENT
    U.S.  ENVIRONMENTAL PROTECTION AGENCY
           CINCINNATI, OHIO  45268

-------
                           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

-------
                            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 im-
proved methodologies that will meet these needs both efficiently
and economically.

     This report contains a status assessment of the air emis-
sions, water pollution, health effects, and environmental signi-
ficance of trichloroethylene.  This study was conducted to
provide a better understanding of the distribution and character-
istics 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 communicate
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 indi-
cative rather than exhaustive.
                                   David G.  Stephan
                                        Director
                     Industrial Environmental Research Laboratory
                                       Cincinnati
                              iii

-------
                            ABSTRACT
Trichloroethylene is a colorless, volatile, nonflammable liquid
at normal temperatures, which has a powerful solvent action on
fats, greases, and waxes.  For this reason, approximately 99%
of all domestic trichloroethylene consumed per year is by metal
and fabric degreasing operations.  Trichloroethylene is also
used in food processing, polyvinyl chloride production, fungicide
manufacturing, textile treating, and medicinal anesthetizing.

United States production in 1974 amounted to 176 x 103 metric
tons and consumption was at 173.7 x 103 metric tons.  However,
these figures have been declining each year because of changes
in production processes and restrictive legislation.

The use of trichloroethylene as a solvent by degreasers is the
major source of emissions.  The four categories of degreasing
operations (cold metal cleaning, open top vapor, conveyorized
vapor, and fabric scouring) emit a total of 116.4 x 103 metric
tons of trichloroethylene per year and open top vapor degreasers
account for 55% of it.  Emissions data from other sources is
unavailable.

Ambient concentrations in the atmosphere have been estimated to
range from 2 ppt to 16 ppt in industrial areas.  The EPA has also
measured traces of trichloroethylene in the water of major cities
and in some drinking water.  However, the environmental impact
of trichloroethylene is not fully understood.

Emission control can best be accomplished through better equip-
ment design and improved operating practices.  The extent of
control technology available to, or being used by, industrial
producers or consumers is unknown.

The use of trichloroethylene has been a matter of great concern
to many governmental agencies.  Evidence that trichloroethylene
is a potent carcinogen has caused industry to avoid this chemi-
cal for many applications.  At present its use is expected to
decline at 8%/yr through 1979.  Based on information contained in
this report, the following should be considered in future
studies:  1) the environmental fate of trichloroethylene, 2) the
extent of control technology in use, 3) information on emission
quantities from production, transportation, or consumer end
products, and 4) an assessment of trichloroethylene's future
market.

                                iv

-------
This report was submitted in partial fulfillment of Contract
68-03-2550 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.
                               v

-------
                            CONTENTS
Foreword	iii
Abstract	   iv
Tables	viii
Conversion Factors and Metric Prefixes 	   ix
Acknowledgement	    x

   1.  Introduction	    1
   2.  Summary	    2
   3.  Source Description	    5
          Physical and chemical properties 	    5
          Production	    6
          Process description	    7
          Uses	    8
          Transportation methods 	    9
   4.  Environmental Significance and Health Effects ....   11
          Environmental significance 	   11
          Health effects 	   14
   5.  Control Technology	   17
          Control methods	   17
          Efficiencies of the control methods	   20
          Economics of control methods 	   20
   6.  Regulatory Action 	   22

References	   24
                               vn

-------
                             TABLES

Number                                                      Page
   1      Trichloroethylene 	   4
   2      Physical and Chemical Properties of Trichloro-
            ethylene	   6
   3      U.S. Trichloroethylene Capacity in 1975 	   7
   4      1974 Degreasing Consumption of Trichloroethylene.   9
   5      Emission Factors for Degreasing Operation Types .  12
   6      Trichloroethylene Toxicity Data for Animals ...  16
   7      Efficiencies of Control Methods 	  21
                              Vlll


-------
             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 101
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 10 k
                         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 380-76e, IEEE Std 268-1976, American Society for Testing and
 Materials, Philadelphia, Pennsylvania, February 1976. - 37 pp.

                                ix

-------
                         ACKNOWLEDGEMENT
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.  Frank,  EPA
Consultant, was principal advisor and reviewer.

-------
                            SECTION 1

                          INTRODUCTION
Trichloroethylene is a highly volatile chlorinated hydrocarbon
which is widely used for degreasing of fabricated metal parts
and, to a lesser extent, in cleaning fluids.  Production and
industrial use result in potential for extensive worker ex-
posure.  Trichloroethylene has been detected in ambient air and
water in industrial areas, in food, and in human tissues.  Tri-
chloroethylene contributes to photochemical smog and is a sus-
pected carcinogen in laboratory animals.

This report on trichloroethylene (CHC1=CC12) provides available
information on the health effects,  environmental behavior and
destiny, production, commercial uses, control technology, and
present regulatory action for trichloroethylene.

-------
                            SECTION 2

                             SUMMARY
Trichloroethylene, CHC1=CC12/ is a colorless, sweet-smelling,
volatile liquid at normal temperatures.  Commercial grades of
trichloroethylene contain stabilizers to prevent decomposition by
oxygen.  Approximately 99% of all domestic trichloroethylene is
consumed by the metal and fabric degreasing trades.  This is
because of its nonflammability,  volatility, and powerful solvent
action for fats, greases, and waxes.  Trichloroethylene is also
used in food processing,  polyvinyl chloride production, fungicide
manufacturing, textile treating, and medicinal anesthetizing.

United States production of trichloroethylene in 1974 amounted to
176 x 103 metric tons;3 however, it dropped in 1975 to 133 x
103 metric tons.  The reason for this decline is because of
changes in production processes and restrictive legislation.
Evidence that trichloroethylene is a carcinogen is not likely to
improve its market position.

As of July 1975, only five companies were producing trichloro-
ethylene.  There are two basic processes depending upon whether
the feedstock is acetylene or ethylene dichloride.  Although the
acetylene process has been the dominant method in the past, only
8% of the reported 1975 capacity relied on it.  The common modes
of shipping trichloroethylene are by barge (47.8%), tank car
(40.3%) and tank truck (11.9%).

Trichloroethylene emissions can occur from three sources:
production, transportation, and consumption.  The main exposure
hazard is believed to be for users  (consumption) rather than
producers.  Domestic consumption in 1974 was 173.7 x 103 metric
tons.

The use of trichloroethylene as a solvent by degreasers is the
major  source of emissions.  Total annual emission quantities for
degreasing operations are given in Table 1.

Ambient concentrations in the atmosphere have been estimated to
range  from 2 ppt  (parts per trillion) to 16 ppt in industrial
 al metric ton = 106 grams; conversion factors and metric system
 prefixes are presented in the prefatory pages of this report.

-------
areas.   The EPA has also measured traces of trichloroethylene in
the water of major cities and in some drinking water.   Due to the
lack of ecological studies,  the impact of trichloroethylene is
not well known.

The primary physiological response from exposure to trichloro-
ethylene is depression of the central nervous system.   In addi-
tion, animal investigation has led to its classification as a
suspected carcinogen.

Emission control can be accomplished through better equipment
design and improved operating practices.  This is particularly
true for metal degreasing operations where proper design and
operation can decrease evaporation and other emissions.  The
extent of control technology in use is unknown.

The use of trichloroethylene in metal degreasing operations and
food processing has been a matter of concern to many governmental
agencies.  In late 1977, the Food and Drug Administration  (FDA)
considered a ban on the use of trichloroethylene in food process-
ing because of its possible carcinogenic effects.

Information on emissions, population exposed, control methods and
regulatory action are summarized in Table 1.  Areas in which
information is not available are noted.  Based upon information
contained in this report, the following should be considered in
future studies:

    • Emission quantities from production, transportation,  or con-
     sumer use of products which may contain trichloroethylene.

    • The environmental  fate of trichloroethylene and information
     on  its transportation routes or degradation in air, water
     or  soil.

    • The extent of control technology utilized by industrial
     producers or consumers and control efficiencies.

    • An  assessment of trichloroethylene1s  future use.

    • Economic  substitute chemicals  for  all  trichloroethylene
     uses.

-------
                                                 TABLE  1.    TRICHLOROETHYLENE
   Emission source
Total emission quantity,
   103 metric tons/yr
                                     Extent of problem
                                                  Population exposed
 Production:

   Acetylene-based:
     Reactor  reflux
       condenser vent

     Tail  gas absorber
       vent

   Ethylene-based:
     None  identified
Transportation:

  Loading

  Transfer

  accidental spills
Produced only at Taft,  Louisiana
  by this process
                      Produced  at  Deer  Park  and
                        Freeport,  Texas, and Baton
                        Rouge and  Lake  Charles,
                        Louisiana  by  this process
                                                                                        Control method
                                                                                                                             Regulation
                                                          Incineration (95%  efficiency)
                                                          Treatment of aqueous  waste
                                                            streams
                                    Incineration (95% efficiency)
                                    Treatment of aqueous waste
                                      streams
                                                         Proper operating practices
                                                                        Workplace exposure limit of
                                                                          100 ppm at 8 hr (OSHA)
                                                                        Trichloroethylene is designated
                                                                          a priority pollutant under
                                                                          Federal Water Pollution  Control
                                                                          Act
Industrial use:

  Cold cleaners
  Open top vapor
    degreasers
  Conveyorized vapor
    degreasers
  Fabric scouring

  Food processing

  Miscellaneous
Consumer use of
  end products:

  Public exposure
    due to use of
    products
        19.5

        63.5

        25.9
         7.5
         _b
         _b
Number of operations:

  149,715

   11,440

    1,713
      693
                                    Proper  design and operation of
                                      equipment  (25% -  60% efficiency)
                                    Carbon  absorption  (95% -  100%
                                      efficiency)
                                    Incineration
                                    Liquid  absorption
                                    Waste solvent reclamation  (90%
                                      efficiency)
                                    Waste solvent landfills
Workplace exposure limit of
  100 ppm in 8 hr (OSHA)
                                                                                             The FDA is considering a ban on
                                                                                               use in foods,  drugs, and cos-
                                                                                               metic products.  Present FDA
                                                                                               limits on trichloroethylene in
                                                                                               decaffeinated instant coffee,
                                                                                               decaffeinated ground coffee,
                                                                                               and spices are 10 ppm, 25 ppm,
                                                                                               and 30 ppm, respectively.
 Extent of use is -mknown.
 Information not known.

-------
                            SECTION 3

                       SOURCE DESCRIPTION
The importance of trichloroethylene in the degreasing industry
cannot be overemphasized.  Its nonflammability,  volatility, low
cost, and powerful solvent action for fats, greases, and waxes.
have made trichloroethylene a standard solvent for the cleaning
of metal parts since World War II.  Perchloroethylene has been
used as a substitute for trichloroethylene and can be made
utilizing similar process technology.

The miscellaneous uses of trichloroethylene are expected to show
the most growth through 1980.  This will primarily be the result
of increased usage in fungicide manufacture and polyvinyl
chloride production.

PHYSICAL AND CHEMICAL PROPERTIES

At normal temperatures trichloroethylene (1,1,2-trichloroeth-
ylene), CHC1=CC12, is a colorless, sweet-smelling, volatile
liquid.  In the absence of stabilizers, the liquid is slowly
decomposed by oxygen in the atmosphere; the vapor, when the
liquid phase is absent, is thermally stable at relatively high
temperatures.  All commercial grades of trichloroethylene con-
tain added stabilizers (1).  Stabilizers are usually added in
quantitites of much less than 1%  (by weight) to the trichloro-
ethylene.  There is a great variety of stabilizers including
acetone, aniline, n-butane, diisopropylamine, isobutyl alcohol,
phenol, and tetrahydrofuran.  The exact mechanism of the sta-
bilizing action is not yet fully understood.

Some of the more important physical and chemical properties of
trichloroethylene are given in Table 2 (1).
 (1) Kirk-Othmer Encyclopedia of Chemical Technology, Second
    Edition, Vol. 5.  John Wiley and Sons, Inc., New York, New
    York, 1969.  pp. 183-195.

-------
            TABLE 2.  PHYSICAL AND CHEMICAL PROPERTIES
                      OF TRICHLOROETHYLENE  (1)
   Physical state, STP                      Colorless liquid
   Molecular weight                                    131.4
   Specific gravity, 20°/4°C                           1.464
   Boiling point, at 760 mm Hg, °C                      86.7
   Melting point, °C                                     -37
   Vapor density, air = 1.0, g/Jl                        4.54
   Latent heat of vaporization, bp, cal/g               57.2
   Specific heat, 80°C, 1 atm, cal/(g)(°C):
     Liquid                                            0.225
     Gas                                               0.156
   Water solubility, g/100 g H2O:
     25°C                                               0.11
     60°C                                              0.125
PRODUCTION

United States production of trichloroethylene in 1974 amounted
to 176 x 103 metric tons, but it dropped in 1975 to 133 x 103
metric tons  (2).

U.S. demand for trichloroethylene was 195 x 103 metric tons in
1974  (3).  Between 1964 and 1974 its growth in demand has been
1.25%/yr; however, it is predicted to drop 8%/yr through 1979
(3).  The reason for this decline is two-fold.  First, restric-
tive legislation, such as the Los Angeles' Rule 66 and the 1970
Clean Air Act, has created a rather uncertain market for the
chemical.  Consequently, manufacturers have delayed the construc-
tion of new plants or the expansion of existing capacity.
Second, the acetylene-based process is now considered outmoded
technology and these plants are being phased out of operation.
In addition, evidence that trichloroethylene is a potent carcin-
ogen has caused many industrial consumers to avoid this chemical
for many applications.

As of July 1975, only five companies were producing trichloro-
ethylene in the United States.  Table 3 summarizes the location,
capacity, and feedstock of these plants (3).
 (2) Chemical Origins and Markets, Fifth Edition.  G. M. Lawler,
    ed.  Chemical  Information Services, Stanford Research
    Institute, Menlo Park, California, 1977.  118 pp.
 (3) Chemical Profile:  Trichloroethylene.  Chemical Marketing
    Report, 208 (12) :9, 1975.

-------
PROCESS DESCRIPTION

There are two basic processes for manufacturing
depending upon the feedstock.  Trichloroethylene may be produced
from acetylene or ethylene dichloride.  Although the acetylene
process has been the dominant method in the past, only 8% of the
reported 1975 capacity relied on this process.

In the acetylene process, acetylene is chlorinated to 1,1,2,2-
tetrachloroethane, which is then dehydrochlorinated by reaction

     TABLE 3.  U. S. TRICHLOROETHYLENE CAPACITY IN 1975 (3)
      Company and location
Annual capacity,3
 103 metric tons
Feedstock
 Diamond Shamrock Chemical Company
 Electro Chemicals Division
 Deer Park,  Texas

 Dow Chemical,  USA
 Freeport,  Texas

 Ethyl Corporation
 Industrial  Chemicals Division
 Baton Rouge,  Louisiana

 Hooker Chemicals and Plastics
  Corporation
 Electrochemical Division
 Taft, Louisiana

 PPG Industries, Inc.
 Industrial  Chemical Division
 Lake Charles,  Louisiana

 TOTAL
       22.7
       68.0
       18.1
       18.1



       90.7

      217.6
Ethylene


Ethylene



Ethylene




Acetylene



Ethylene
  plant capacities are very flexible, since at least one other
  chlorinated hydrocarbon can be made in the same equipment,
  depending on demand.
(4)  Sittig, M.  Pollution Control in the Organic Chemical
    Industry.  Noyes Data Corporation, Park Ridge, New Jersey,
    1974.  304 pp.

-------
with calcium hydroxide or by pyrolysis to yield trichloroethyl-
ene.  The  process  reactions are shown below  (4) :


                               +Ca (OH) 2 - ^ 2CHC1=CC12 + CaCl2 + 2H20
                              /            trichloro-  calcium  water
  2HC=CH + 4C12 - 2CHC12CHC12 — /            ethylene   chloride
  acety-   chlo-   1,1,2,2-      \
  lene     rine    tetrachloro-  \Pyro ysis — ^ 2CHC1=CC12 + 2HC1
                 ethane                   trichloro-  hydrogen
                                          ethylene   chloride

In addition, perchloroethylene  can  be produced by oxychlorination
of the ethylene  dichloride as illustrated below  (5) :
2CH2C1CH2C1 + 1.5 C12 + 1.75 O2            CHC1=CC12 + C12C=CC12 + 3.5 H2O


The amount of  perchloroethylene coproduced can be controlled
according  to the mole ratio of dichloride to chlorine  in the
feed.

Other processes are technically available for the manufacture of
trichloroethylene  but are not commercially competitive with the
two methods described above.

USES

Trichloroethylene  is a powerful solvent for a large number of
natural and synthetic organic substances.  It is also  nonflam-
mable under conditions of normal use.  Because of its  powerful
solvent action for fats,  greases,  and waxes and its nonf lammabil
ity and volatility,  trichloroethylene has become one of the most
important  industrial chlorinated solvents for vapor degreasing
and dry cleaning.

Vapor degreasers operate  by condensation of vaporized  solvent
on the surface of  the metal parts.  The condensing solvent
dissolves  away oil and grease,  and washes the parts as it drips
down into  a collection tank.   Cold cleaners remove oil base
impurities from metal parts in a batch loaded procedure that
can include spraying,  brushing,  flushing, and immersion.

The types  of degreasing performed in the United States fall into
four categories, which are 1)  cold cleaning, 2)  open top vapor
(5) Lowenheim, F. A., and M.  K.  Moran.   Faith, Keyes, and
    Clark's Industrial Chemical,  Fourth Edition, John Wiley and
    Sons, Inc., New York, New York,  1975.   pp. 605-607.  845-848.
                                 8

-------
degreasing, 3) conveyorized vapor degreasing, and 4) fabric
scouring (6).

Each type of degreasing requires specific solvents.  Trichloro-
ethylene is needed in all four categories to some extent.
Table 4 presents the 1974 consumption pattern for degreasing
operations  (6).  Total domestic consumption of trichloroethylene
in 1974 was 173.7 x 103 metric tons  (6); therefore, degreasing
operations represent 99% of total U.S. consumption.

 TABLE 4.  1974 DEGREASING CONSUMPTION OF TRICHLOROETHYLENE  (6)


                                     Average
      Degreasing       Number of   consumption    U.S. Total
      operation	operations	kg/yr	10 3 metric tons
Cold cleaning
Open top vapor
Conveyorized vapor
Fabric scouring
TOTAL
149,715
11,440
1,713
693

293
7,165
17,780
21,664

43.8
82.0
30.7
15.0
171.5

Trichloroethylene was also used in food processing, chiefly in
the extraction of caffeine for decaffeinated coffee, and in
polyvinyl chloride production as a chain terminator.  Other uses
of trichloroethylene included fungicide manufacturing, textile
treating, and medicinal anesthetizing.

TRANSPORTATION METHODS

Shipment of trichloroethylene can be by tank cars or tank trucks
or in iron drums, cans, or bottles.  It will not attack the com-
mon metals, even in .the presence of moisture.  Although no
Department of Transportation shipping label is required, the
Manufacturing Chemists Association does require a warning label
(5).   The common modes of transportation for trichloroethylene
are by barge  (47.8%), tank car  (40.3%), and tank truck (11.9%)  (7).
(6)   Hoogheem, T. J.,  P. J. Marn, and T. Hughes.  Source Assess-
     ment:  Solvent Evaporation - Degreasing.  Contract 68-02-
     1874, U.S. Environmental Protection Agency, Cincinnati,
     Ohio.  (Final document submitted to the EPA by Monsanto
     Research Corporation, November 1977.)   180 pp.

(7)   Ocean Affairs Board, National Research Council.  Assessing
     Potential Ocean Pollutants, Report 0-309-02325-4, U.S.
     Environmental Protection Agency and National Science
     Foundation, Washington, D.C., January 1975.  456 pp.

-------
Trichloroethylene should be stored in a cool, dry, well-venti-
lated area, away from acute fire hazards and direct sunlight.   It
should also be protected from excessive heat and sudden tempera-
ture increases.  Ultraviolet radiation and high temperatures can
result in chemical degradation.
                               10

-------
                            SECTION 4

          ENVIRONMENTAL SIGNIFICANCE AND HEALTH EFFECTS
ENVIRONMENTAL SIGNIFICANCE

Since detailed ecological studies have not yet been made, the
environmental impact of trichloroethylene is not well known.
Studies in England, however, have revealed that traces of tri-
chloroethylene have been noted in samples of air, water, soil,
and marine life (7).  Precise transport routes or degradation
processes were not suggested.

Sources of Emissions

Trichloroethylene emissions can occur from three sources:  pro-
duction, transportation, and consumption.  In the acetylene-
based process, there are two sources of air pollution, the vent
on the reactor reflux condenser and the vent on the tail gas
absorber (5).  For the ethylene-based process, no specific
process units have been identified as potential emission
sources.  There is general agreement that the main exposure
hazard is for users rather than producers, since the chemical is
made in a closed system.  Pittsburgh Plate Glass and Dow Chemical
companies report levels in their production plants well below
100 ppm  (parts per million)  (8).

The quantity of trichloroethylene discharged from domestic
transport is very difficult to evaluate.  Emissions occur almost
inevitably from loading and transfer operations and accidental
spills (7).

The major source of emissions resulting from trichloroethylene
consumption can be attributed to its use as a solvent in open top
and conveyorized vapor degreasers.  Emissions occur due to diffu-
sion and evaporation from the solvent bath, solvent carry-out on
(8)  Reactions Grow to Trichloroethylene Alert.  Chemical &
     Engineering News, 53 (20) :41-43, 1975.

                                11

-------
parts, waste solvent evaporation, and exhaust (9).   Table 5 pre-
sents emission factors for the four categories of degreasing (6).
These four categories of degreasing operations emit a total of
116.4 x 103 metric tons of trichloroethylene per year and open
top vapor degreasers account for 55% of it.

  TABLE 5.  EMISSION FACTORS FOR DEGREASING OPERATION TYPES (6)


                                    Emissions factor,9
         Degreasing operation	g/kg solvent consumed

         Cold cleaning                  430 ± 30%
         Open top vapor                 775 ± 30%
         Conveyor!zed vapor             850 ± 30%
         Fabric scouring                500 ± 30%


    Emission factors were calculated in Reference 6 by deter-
    mining the difference between the total amount of solvent
    utilized and the amount accountable through degreaser
    waste solvent activities.  Thus, all solvents used within
    a specific degreasing operation are assumed to have the
    emission factor calculated for that operation.

Environmental Levels

Traces of trichloroethylene have been found in air and water
samples taken in industrialized areas across the United States.
Ambient concentrations in the atmosphere have been estimated by
industry to range from 2 ppt to 16 ppt.  Water concentrations
have been measured at about 0.1 ppt (10).  The U.S. Environmental
Protection Agency has also measured traces of trichloroethylene
in the water of major cities and in some drinking water (10, 11).
There have also been several reports of contamination of wells
and ground waters from careless disposal practices and accidents.
Trichloroethylene levels in the soil are either unknown or the
data are not readily available.
 (9) Control Techniques for Volatile Organic Emissions from
     Stationary Sources.  (Draft report by Radian Corporation,
     AP-68), Contract 68-02-2608, U.S. Environmental Protection
     Agency, Research Triangle Park, North Carolina, July 1977.
(10) Office of Toxic Substances.  Summary Characterizations of
     Selected Chemicals of Near-Term Interest.  EPA-560/4-76-
     004, U.S. Environmental Protection Agency, Washington,
     D.C., April 1976.  50 pp.

(11) Shakelford, W. M., and L. H. Keith.  Frequency of Organic
     Compounds Identified in Water.  EPA-600/4-76-062, U.S.
     Environmental Protection Agency, Athens, Georgia, December
     1976.  629 pp.


                               12

-------
  Secondary Effects

 Since the environmental fate of trichloroethylene is not com-
 pletely understood, assessing the secondary environmental effects
 of this chemical would depend more on speculation than on fact.
 The atmospheric photoxidation of trichloroethylene is the only
 environmental process for which any definitive data exist.   The
 oxidation is believed to follow two main courses, the initial
 stages of which are the formation of the following oxygen
 compounds:

                C12C                          C12C-0
                ClHcP^0                      C1HC-0

                  (A)                            (B)

 During the  oxidation,  a small  amount of hexachlorobutylene  is
 formed by dimerization of the  trichloroethylene.   Over 80%  of
 the initial oxidation products  consists of compound (A).  Com-
 pound (A)  decomposes  to yield  dichloroacetyl  chloride, ClaCHCOCl;
 compound (B)  yields phosgene,  carbon monoxide,  and hydrogen
 chloride (1).
        *

 Very  little information is  available on the degradation of  tri-
 chloroethylene  in  aqueous environments  and soils.   Various  routes
 of  chemical and biological  degradation  have been  suggested  but
 no  definitive data exist.   It has only  been suggested  that  sig-
 nificant  amounts of trichloroethylene evaporate from the water
 or  soil  and undergo photoxidation in the atmosphere; however,  no
 definitive  data have been reported  (7).

 Population  at Risk

 According to recent estimates  (10),  over 20,000 workers are
 directly  exposed to trichloroethylene at five manufacturing
 plants and  the  many companies which  routinely use  solvent metal
 cleaning  operations.   In  addition, the  general  public  is indi-
 rectly exposed  via inhalation of cleaning  fluids and ingestion
 of  foods, spices,  and medicines from which undesirable components
 have been removed  by trichloroethylene  extraction.  Foreign
 studies have detected residues ranging  from 0.02 ppt to 22.0 ppt
 in  human tissue  (10).  The Food and  Drug Administration is
 currently determining if  trichloroethylene can  be detected in
 their food monitoring program.

Reactions and Pathways in the Environment

Since trichloroethylene has a low solubility,  high vapor pres-
sure, and relatively high photodegradation rate at sea level, it
is not expected to accumulate in the atmosphere.  The reported
half-life of trichloroethylene in air ranges from 157 minutes


                               13

-------
(7)  to eight hours (.10) .   Trichloroethylene is oxidized by ozone
to yield phosgene, hydrogen chloride, carbon monoxide, and
dichloroacetylchloride (12).   This autoxidation process is
greatly enhanced by high temperatures and exposure to light,
especially ultraviolet radiation.  Even so, traces of trichloro-
ethylene as high as 160 ppt have been noted in the industrial
areas of England  (7).  More study is needed in the area of
atmospheric degradation to solve this contradiction.

The possibility of water pollution by trichloroethylene has
recently become a matter of some concern.  Mollusks around Port
Erin, Isle of Man, where the waters are considered relatively
unpolluted, were found to contain traces of trichloroethylene
(7).  This can be taken as an indication that trichloroethylene,
which has a half-life in water on the order of months, is
entering the biological food chain of the ocean.  As of yet,
adverse ecological effects have not been reported.

HEALTH EFFECTS

The primary physiological response from exposure to trichloro-
ethylene is depression of the central nervous system.  Prolonged
moderate exposure may cause headaches and drowsiness.  Acute
exposure may lead to ventricular fibrillation resulting in
cardiac failure and death  (13).  In addition, animal investiga-
tion has led to the classification of trichloroethylene as a
suspected carcinogen  (14).

Effects on Humans

Nervous system depression is the dominant problem from acute
exposure to trichloroethylene.  Visual disturbances, mental con-
fusion, fatigue, and sometimes nausea and vomiting are observed.
The dangers in industry are accentuated by lack of coordination
which may lead to poor manual manipulation and, consequently,
unsafe mechanical operations.  In some instances, a form of
addiction has been observed in exposed workers.
 (12) Dorigan, J.  Scoring of Organic Air Pollutants:  Chemistry,
     Production and Toxicity of Selected Synthetic Organic
     Chemicals.
 (13) Sax,  I. N.  Dangerous Properties of Industrial Materials,
     Fourth Edition, Van Nostrand Reinhold, New York, New York,
     1975.  1258 pp.

 (14) Registry of Toxic Effects of Chemical Substances.
     Christensen, H. E. and E. J. Fairchild,  ed.  Contract
     210-75-0034, U.S. Department of Health,  Education,  and
     Welfare, Rockville, Maryland, June 1976.  1245 pp.

                               14

-------
Chronic exposure to low levels of trichloroethylene can cause
growth depression, liver injury and kidney changes (15) although
injury is not definitely established as a result of chronic
exposure (13, 16).  Even though moderate exposure does not have
the same dramatic effect on the nervous system as acute exposure,
symptoms similar to alcohol inebriation can occur.  In one study,
six students exposed to 110 ppm for two 4-hr periods separated by
1 1/2 hr showed significantly lower levels of performance in per-
ception, memory, and manual dexterity tests (10).

In April 1961, the American Conference of Governmental Industrial
Hygienists established the threshold limit for trichloroethylene
at 100 ppm (15).

In addition to these limits and gradations, a variety of dosages
and concentrations have been determined as a measure of the
effect of trichloroethylene on humans.  The lowest published
oral lethal dose is 857 mg/kg.  For inhalation, the lowest pub-
lished toxic concentration is 160 ppm in 83 min and 110 ppm in
8 hr for a man (14).

Studies have also determined that the body retains a significant
amount of trichloroethylene for some period of time following
exposure.  The percentage of inhaled trichloroethylene that is
exhaled ranges from 21% to 28% for a short exposure and 32% to
60% for a long exposure.  The remainder is excreted or converted
in some other way  (unknown metabolites).  Approximately 1.2% to
7.8% are recovered in the urine as trichloroacetic acid (15).
In fact, the excretion of trichloroacetate is considered a
reasonable index of exposure to trichloroethylene.

Effects on Animals

Experimental work done on animals is the major basis for the
link between trichloroethylene and abnormalities in the liver
and kidney.  Experiments completed in 1951 showed that rats and
rabbits exposed to 3,000 ppm of trichloroethylene for 7 hr/day,
5 days/wk during a 6-month period experienced an increase in
liver and kidney weight.  At lower concentrations (400 ppm), the
increase in liver and kidney weight was still noticeable in rats,
but much less dramatic than before.  In addition, many animals,
particularly the male of the species, showed less growth (15).
Threshold dosages and concentrations for several animals are
given in Table 6  (14) .
(15) Industrial Hygiene and Toxicology, Volume II.  F. A. Patty,
     ed.  John Wiley and Sons, Inc., New York, New York, 1962.
     2305 pp.

(16) The Merck Index, M. Windholz, ed.  Merck and Co., Inc.,
     Rahway, New Jersey, 1976.  1313 pp.

                               15

-------
TABLE 3.  TRICHLOROETHYLENE TOXICITY DATA FOR ANIMALS (14)
Animal
Rat
Route
Oral
Inhalation
Acute
toxicity
LD50b
LCLO
Dosage
4,920 mg/kg
8,000 ppm (4 hr)
Mouse    Oral
         Inhalation
         Intravenous

Dog      Oral                LD
         Intraperitoneal     LD
         Intravenous         LD

Rabbit   Inhalation          LC
         Subcutaneous        LD
                                 LO
                                 50
                                 LO
                                 LO
                                 LO
135 g/kg (27 wk)
3,000 ppm (2 hr)
        34 mg/kg

     5,860 mg/kg
     1,900 mg/kg
       150 mg/kg

      11,000 ppm
     1,800 mg/kg
   Lethal dose;  50 percent kill.
   Lowest lethal concentration.
  'Lowest toxic  dose.
   Lowest lethal dose.
                            16

-------
                             SECTION  5

                        CONTROL  TECHNOLOGY


 The  available methods  for  controlling  trichloroethylene  emissions
 from production,  transportation,  and consumption  operations will
 vary only  slightly.  Any major  differences will be  reflected  as
 emission reductions  economically  achievable.

 CONTROL METHODS

 In almost  all instances emission  control can be accomplished
 through better equipment design and  improved operating practices.
 This is particularly true  for metal  degreasing operations where
 proper design and operation  can decrease evaporation and carry-
 out  emissions.

 For  the production of  trichloroethylene the major emission
 sources are vents on the reactor  reflux condenser and tail gas
 absorber,  gaseous waste streams,  and aqueous waste  streams.   The
 recommended method of  control for vents and gaseous waste
 streams is incineration, preferably  after mixing with another
 combustible fuel.  Care must be exercised to assure complete
 combustion in order  to prevent the formation of phosgene.  In
 addition,  an acid scrubber is necessary to remove the halogen
 acids produced.  Control methods  for aqueous waste  streams would
 involve some type of separation process before final water dis-
 charge.  Likely separation processes would be distillation,
 liquid-liquid extraction, and carbon adsorption.  No details  are
 available as to which, if any, are in use.

 For  the transportation of trichloroethylene, the best means of
 emission reduction is proper operating practices.  Care must
 always be taken when handling a chemical which might contaminate
waters in the event of an accident.  Spill prevention is essen-
 tial, but if a spill should occur, personnel should be prepared
 to properly contain the liquid.   Any transfer operation will
probably result in evaporation,  but proper handling can reduce
the amount so that vapor recovery is unnecessary.  In any event,
safety of the personnel requires that the transfer area be
properly ventilated.

Trichloroethylene is predominantly used as a solvent in open top
vapor degreasers.  Major emissions from these degreasers result
from diffusion and evaporation from the solvent bath,  solvent

        5                       17

-------
carry-out, exhaust, and waste solvent evaporation.  The best
method for reducing most of these emissions is simply proper
design and operation.

The cover is the single most important control device for open
top vapor degreasers.  They have been shown to reduce total emis-
sions by 20% to 40%; effectiveness varies depending upon the
frequency of cover use (6).  Diffusion and evaporation losses can
also be reduced by as much as 50% if the freeboard ratio is
increased from 0.5 to 1.0 (9).  The freeboard for an open top
vapor degreaser is the air layer above the vapor zone which is
cooled by a series of condensing coils that ring the internal
wall of the jacket.  The freeboard typically ranges from 50% to
70% of the width of the vapor degreaser and protects the solvent
vapor zone from disturbance caused by air movement around the
equipment.  The freeboard ratio is defined as the freeboard
height divided by the width of the air/solvent area and is
usually 0.5 to 0.75.  By increasing the freeboard ratio from 0.5
to 0.75 for an idle open top vapor degreaser, emission reductions
of 25% to 30% are expected  (9).

Another design change is the use of refrigerated chillers.  Re-
frigerated chillers are a second set of condenser coils located
slightly above the primary condenser coils of the degreasers.
By creating a cold blanket of air immediately above the vapor
zone, refrigerated chillers are estimated to reduce emission
rates by approximately 40%.  Actual tests on below freezing
(-23°C to -29°C) units have achieved reductions of 28% to  62% (9).

Collection and removal of trichloroethylene vapors by carbon
adsorbers, incinerators, and liquid absorbers are also possible.
Carbon adsorption is a well proven technology for the control of
solvent emissions from degreasing operations, particularly for
spray chambers where the area must be exhausted to protect the
operator.  Activated carbon has a very good capacity for common-
ly used solvents such as trichloroethylene, perchloroethylene,
and 1,1,1-trichloroethane.  Although carbon adsorption units can
remove 95% to essentially 100% of the organic input to the bed,
reductions in the total solvent emission are only 40% to  65%.
Many systems achieve less than 40% emission reduction because of
poor inlet collection efficiency and an improperly maintained or
adjusted carbon adsorber  (9).

Although incineration is widely used for emission control in
many industries, special problems make it an unattractive option
for degreasing operations.  For instance, chlorinated hydro-
carbons present in  the organic solvents are pyrolized at  incin-
erator temperatures  releasing chlorine, hydrochloric acid, and
phosgene.  Removal  of these gases from the incinerator exhaust
requires additional  gas cleaning equipment.  Cold cleaners often
use solvents of low volatility, so combustion requires the use
of supplemental fuel.  These  factors, along with  the high capital
cost, make incineration an  unlikely choice for emission control.
                               18

-------
Liquid absorption is also a well-known method of controlling
organic emissions, but has design problems which make it an
impractical alternative.  For example, trichloroethylene vapors
are easily absorbed by mineral oil.  The absorption column is
operated at 30°C and the column effluent contains about 120 ppm
mineral oil vapors.  In essence, one emission problem is ex-
changed for another.  Chilling the absorbing fluid would reduce
the concentration of mineral oil in the exhaust gas, but would
also lead to ice formation within the column and greatly in-
crease the energy requirement.

Carry-out emissions can be appreciable if proper materials
handling procedures are not followed.  While drainage facilities
are used to control emissions from cold cleaners, no special
controls have been reported for open top vapor degreasers.

Exhaust emissions result when exhaust rates for open top vapor
degreasers are set too high.  The average exhaust rate is
0.25 m3/s m2 of degreaser opening (9).  However, this rate is
sometimes exceeded in order to comply with OSHA regulations on
solvent threshold limit values (TLV®).  For trichloroethylene the
TLV is 100 ppm or 535 mg/m3 (17).

Emissions from waste solvent evaporation occur in a number of
different ways,  none of which can easily be monitored or quanti-
fied.   Approximately one-third of the total solvent emissions
from degreasing operations are estimated to be from waste solvent
evaporation.  Recommended methods of waste solvent disposal
include reclamation, direct incineration, and chemical landfills.

Solvent reclamation is considered the best method for reducing
emissions from evaporation of waste solvent since almost 90%
of the solvent is recovered as usable product.   Reclamation can
be done through a private contractor or in-house distillation.
Private contractors usually collect waste solvent,  distill it,
and return the reclaimed portion.  Users are charged about half
the market value of the solvent.   This method is economically
attractive in industrial areas where users are not separated by
large  distances.

In-house distillation is common among users employing multiple
open top degreasers.  One report states that the annual operating
costs  of an in-house reclamation system are recovered from the
first  1.32 m3 of chlorinated solvents distilled.  In-house
(17)  TLVs® Threshold Limit Values  for  Chemical  Substances and
     Physical  Agents in the Workroom Environment  with Intended
     Changes  for  1976.   American Conference  of  Governmental
     Industrial Hygienists,  Cincinnati,  Ohio, 1976.   94 -pp.
                               19

-------
distillation involves some significant problems.   These include
disposal of distillate bottoms containing metals  and sludge,
decomposition of chlorinated solvents, formation  of azeotropes,
and occurrence of adverse chemical reactions.

Direct incineration is not as desirable as reclamation since it
does not result in a usable product.  Furthermore, it may require
substantial amounts of supplemental fuel.  Incineration requires
temperatures of 1200°C, sufficient residence time (about 2 s),
and exhaust gas cleaning equipment.  Although capital invest-
ments are high, operating costs have been estimated at less than
4.4C/kg of waste solvent incinerated.

Most chemical landfills are presently inadequate  as waste solvent
disposal methods.  Chemical landfills would be suitable if
steps were taken to eliminate evaporation and permeation.  One
method under consideration involves sealing the waste solvent
in lined drums and surrounding these drums with 1.2 m to 6.1 m
of packed clay.  This method has not been demonstrated.

EFFICIENCIES OF THE CONTROL METHODS

The efficiency of any specific control method will depend on a
number of operating variables such as temperature, residence
time, and the amount and nature of the waste gas.  In addition,
adequate maintenance of emission control equipment is a prereq-
uisite for proper operation.  The efficiencies of the control
methods discussed and documented in the previous section are
summarized in Table 7  (9).  No information is available on the
extent to which any of the control measures discussed are being
utilized in plants practicing degreasing  (6).

ECONOMICS OF CONTROL METHODS

Estimating the economics of a particular control method is a
very complicated matter.  Proper operation and maintenance of
manufacturing equipment and careful handling and storage of tri-
chloroethylene result  in minor costs, if any.

The costs of add-on pollution abatement equipment can cover a
broad spectrum and will depend on the amount and nature of the
waste, the difficulty  in retrofitting any necessary equipment,
and the recurrent use  of additional materials such as catalyst,
supplemental fuel, or  activated carbon.  No definitive data for
trichloroethylene are  presently available.  A general discussion
of environmental control methods for volatile organic emissions
can be found in the recently revised draft edition of EPA pub-
lication AP-68  (9) .
                                 20

-------
  TABLE 4.  EFFICIENCIES OF CONTROL METHODS (9)S

~~~ ~~~                            ~      Removal
	Control method	efficiency,

Production of trichloroethylene
  Incineration of vent and waste gas       95+
  Treatment of aqueous waste streams

Transport of trichloroethylene
  Proper handling and storage

Consumption of trichloroethylene
  Increased freeboard ratio on
    open top vapor degreasers           25 to 50
  Refrigerated chillers                 28 to 62
  Carbon adsorption                     95 to 100
  Waste gas incineration                   95+
  Liquid absorption
  Waste solvent reclamation                90
  Waste solvent incineration               95+
  Waste solvent landfills
aBlanks indicate information unknown or unavailable.
                        21

-------
                            SECTION 6

                        REGULATORY ACTION


The use of trichloroethylene in metal degreasing operations and
food processing has been a matter of concern to many governmental
agencies.  Perhaps the most restrictive legislation has been the
Los Angeles Air Pollution Control District's Rule 66 which was
passed in December 1974.  According to Rule 66, not more than
20% by volume of trichloroethylene could be used in formulating
solvent blends that are evaporated into the atmosphere.  In
addition, the sum of all restricted solvents in the final solvent
blend could not exceed 20% by volume.  Rule 66 also prohibited
vapor degreasing plants from discharging into the atmosphere
more than 17 kg of trichloroethylene in any single day, or more
than 3.6 kg of trichloroethylene in any one hour, unless the
discharge had been reduced by at least 85%.  Amendments to
Rule 66 have been even/!more restrictive.  Although Rule 66 ap-
plies to only a small portion of the country, environmentally
conscious communities have adopted parts of it for their own use.

Since trichloroethylene contributes to photochemical smog, State
Implementation Plans  (SIP) provide a mechanism for limiting
emissions.  Discharge permits limiting biological oxygen demand
(BOD), chemical oxygen demand (COD), and suspended solids also
provide some control over effluent discharges.  Detailed health,
environmental, and economic analyses are being conducted to
determine the necessity of revisions to these regulations.

In 1973, the National Institute for Occupational Safety and
Health,  (NIOSH) recommended that the Occupational Safety and
Health Administration  (OSHA) establish worker exposure limits at
100 ppm trichloroethylene with a peak concentration of 150 ppm
trichloroethylene.  In July 1975, the American Conference of
Governmental Industrial Hygienists determined that there is
insufficient evidence to warrant any change in the existing tri-
chloroethylene TLV set at 100 ppm.  The maximum allowable con-
centration  is 200 ppm provided the TLV does not exceed 100 ppm.
For a maximum cumulative exposure of 5 min in any 2-hr period,
the acceptable maximum peak above the maximum allowable con-
centration  is 300 ppm.

In April  1975, a  "memorandum of alert" was issued by the National
Cancer  Institute  (NCI) concerning the link between trichloro-
ethylene  and cancer in mice.  The NCI has begun  studies to

                                22

-------
determine effects on humans.  In addition, trichloroethylene
producers have conducted epidemiological studies, long-term
animal feeding studies, and long-term animal inhalation studies.
And an in-depth literature survey has also been completed for
the Manufacturing Chemists Assocation (MCA).

The Food and Drug Administration (FDA) has been urged to ban the
use of trichloroethylene in food processing because of its pos-
sible carcinogenic effects.  At present the FDA limits trichloro-
ethylene to 10 ppm in decaffeinated instant coffee, 25 ppm in
decaffeinated ground coffee, and 30 ppm in spices (8).  The
Commissioner of Food and Drugs expects to issue final regula-
tions ba,sed on proposals no later than January 25, 1978 (18).
These proposals would amend regulations by prohibiting trichloro-
ethylene in human food, drugs, and cosmetic products or in animal
food and drugs, because it may pose a risk of cancer in man or
animals.

Trichloroethylene has been designated a priority pollutant under
the Federal Water Pollution Control Act.
(18)  Code of Federal Regulations 21 - Food and Drug Administra-
     tion - Parts 73,  172,  173,  175,  177,  189, 250, 500,  510,
     700  - Trichloroethylene - Proposed Rules.  Federal Register,
     42(187):49464-49471,  1977.

                               23

-------
                           REFERENCES
 1.   Kirk-Othmer Encyclopedia of Chemical Technology,  Second
     Edition,  Vol.  5.   John Wiley and Sons,  Inc.,  New York,  New
     York,  1969.  pp.  183-195.

 2.   Chemical  Origins  and Markets,  Fifth Edition.   G.  M.  Lawler,
     ed.   Chemical  Information Services, Stanford  Research
     Institute,  Menlo  Park, California,  1977.   118 pp.

 3.   Chemical  Profile:  Trichloroethylene.   Chemical Marketing
     Reporter, 208(12):9, 1975.

 4.   Sittig, M.   Pollution Control  in the Organic  Chemical
     Industry.  Noyes  Data Corporation,  Park Ridge, New Jersey,
     1974.   304  pp.

 5.   Lowenheim,  F.  A., and M. K. Moran.   Faith,  Keyes, and
     Clark's  Industrial Chemical, Fourth Edition,  John Wiley and
     Sons,  Inc., New York, New York,  1975.   pp.  605-607,
     845-848.

 6.   Hoogheem, T.  J.,  P.  J. Marn, and T. Hughes.   Source Assess-
     ment:   Solvent Evaporation - Degreasing.   Contract 68-02-
     1874,  U.S.  Environmental Protection Agency, Cincinnati,
     Ohio.   (Final  document submitted to the EPA by Monsanto
     Research  Corporation, November 1977.)   180  pp.

 7.   Ocean Affairs  Board, National  Research  Council.  Assessing
     Potential Ocean Pollutants, Report  0-309-02325-4, U.S.
     Environmental  Protection Agency and National  Science
     Foundation, Washington,  D.C.,  January 1975.   456  pp.

 8.   Reactions Grow to Trichloroethylene Alert.  Chemical &
     Engineering News, 53 (20) :41-43,  1975.

 9.   Control Techniques for Volatile Organic Emissions from
     Stationary  Sources.   (Draft report  by Radian  Corporation,
     AP-68), Contract  68-02-2608, U.S. Environmental Protection
     Agency,  Research  Triangle Park,  North Carolina, July 1977.

10.   Office of Toxic Substances.  Summary Characterizations  of
     Selected  Chemicals of Near-Term Interest.   EPA-560/4-76-
     004,  U.S. Environmental Protection  Agency,  Washington,
     D.C.,  April 1976.  50 pp.

                               24

-------
11.  Shackelford, W. M.,  and L. H. Keith.  Frequency of Organic
     Compounds Identified in Water.  EPA-600/4-76-062, U.S.
     Environmental Protection Agency, Athens, Georgia, December
     1976.  629 pp.

12.  Dorigan, J.  Scoring of Organic Air Pollutants:  Chemistry,
     Production and Toxicity of Selected Synthetic Organic
     Chemicals.

13.  Sax, I. N.  Dangerous Properties of Industrial Materials,
     Fourth Edition.  Van Nostrand Reinhold, New York, New York,
     1975.  1258 pp.

14.  Registry of Toxic Effects of Chemical Substances.
     Christensen, H. E. and E. J. Fairchild, ed.  Contract 210-
     75-0034, U.S. Department of Health, Education, and
     Welfare, Rockville,  Maryland, June 1976.  1245 pp.

15.  Industrial Hygiene and Toxicology, Volume II.  F. A.  Patty,
     ed.  John Wiley and  Sons, Inc., New York, New York,  1962.
     2305 pp.

16.  The Merck Index, M.  Windholz, ed.  Merck and Co., Inc.,
     Rahway, New Jersey,  1976.  1313 pp.

17.  TLVs® Threshold Limit Values for Chemical Substances  and
     Physical Agents in the Workroom Environment with Intended
     Changes for 1976. American Conference of Governmental
     Industrial Hygienists, Cincinnati, Ohio, 1976.  94 pp.

18.  Code of Federal Regulations 21 - Food and Drug Administra-
     tion - Parts 73, 172, 173, 175, 177, 189, 250, 500,  510,
     700 - Trichloroethylene - Proposed Rules.  Federal Register,
     42(187) :49464-49471, 1977.
                               25

-------
                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
  REPORT NO.
  EPA-600/2-79-210m
                                                            3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
                                                            5. REPORT DATE
                                                              December 1979  issuing date
 Status Assessment  of Toxic Chemicals:   Trichloroethylene
                                                            6. PERFORMING ORGANIZATION CODE
 '. AUTHOR(S)
 T.R.  Blackwood, J.C.  Ochsner
 W.C.  Micheletti
                                                            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    1^07             P.O.  Box 99^8
                                  Austin,  Texas  78766
                                                            10. PROGRAM ELEMENT NO.
                  1AB60U
             11. CONTRACT/GRANT NO.

                  68-03-2550
12. SPONSORING AGENCY NAME AND ADDRESS
 Industrial Environmental Research Lab«  - Cinn, OH
 Office of Research  and Development
 U.S.  Environmental  Protection Agency
 Cincinnati, Ohio    1+5268
             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,  513-68i|-UU8l.
16. ABSTRACT
             The production processes,  uses, and properties  of trichloroethylene
             are revealed in this report.   The sources and amounts of trichloro-
             ethylene  pollution are  identified as well as  the health effects  and
             environmental significance.   Current control  technologies are  identi-
             fied,  along with assessments  on their cost  and  effectiveness.  Recent
             regulatory actions are  explained and areas  where further study is
             called for are identified.
17.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                               b.IDENTIFIERS/OPEN ENDED TERMS  C.  COS AT I Field/Group
 Hydrocarbons, aliphatic hydrocarbons,
 Ethylene
 Trichloroethylene, De-
 greasing, Anesthetic,
 Food Processing Textile
 Treatment,  Polyvinyl
 Chloride Production,
 Fungicides,  Halogenated
 Aliphatics          	
68A
68D
68G
18. DISTRIBUTION STATEMENT
 Release to Public
                                               19. SECURITY CLASS (ThisReport)
                                                Unclassified
                           21. NO. OF.PAGES
                                 36
20. SECURITY CLASS (This page)
 Unclassified
                                                                          22. PRICE
 EPA Form 2220-1 (Rev. 4-77)
                       PREVIOUS EDITION IS OBSOLETE
                                              26
                                                                   TV U S. GOVERNMENT PRINTING OFFICE: 1980 -657-146/5516

-------