United States
                 Environmental Protection
                 Agency
Pollution Prevention
and Toxics
(7407)
November 1994
EPA 749-F-95-020
&EPA     OPPT  Chemical  Fact Sheets
                    1,2,4-Trichlorobenzene (CAS No.  120-82-1)
                Chemicals can be released to the environment as a result of their
                manufacture, processing, and use.  EPA has developed information
                summaries on selected chemicals to describe how you might be
                exposed to these chemicals, how exposure to them might affect you
                and the environment, what happens to them in the environment, who
                regulates them, and whom to contact for additional information. EPA is
                committed to reducing environmental releases of chemicals through
                source reduction and other practices that reduce creation of pollutants.
  WHAT IS 1,2,4-TRICHLOROBENZENE, HOW IS IT USED, AND HOW MIGHT I BE EXPOSED?

        1,2,4-Trichlorobenzene (also known as trichlorobenzene or TCB) is a nonflammable liquid. It does not occur
  naturally.  TCB is produced in large amounts (estimated to be between 22 million and 32 million pounds in 1990) by
  two companies in the United States. Because of environmental concerns for chlorinated organic chemicals U.S.
  demand for TCB is likely to fall.  The largest users of TCB are companies that use it as a solvent to make dyes and
  other chemicals. It can also be added to dielectric fluids, transformer oils, cleaners, and lubricants.

        Exposure to 1,2,4-trichlorobenzene can occur in the workplace or in the environment following releases to air,
  water, land, or groundwater.  TCB enters the body when people breathe air or consume food or water contaminated
  with TCB. It can also be absorbed through skin contact. Once in the body small amounts of TCB can remain, stored
  in fat tissue.
  WHAT HAPPENS TO TCB IN THE ENVIRONMENT?

        1,2,4-Trichlorobenzene evaporates slowly when exposed to air. It mixes poorly in water. Most direct releases
  of TCB to the U.S. environment are to air. TCB also evaporates slowly from surface water and soil exposed to air.
  Once in air, it breaks down to other chemicals. Unless it evaporates, TCB is likely to stay in soil and water.
  Microorganisms that live in soil can break down small amounts of TCB. Because TCB sticks to soil, it is not likely to
  move into deep soil. If released into deep soil, TCB can move through the ground and enter groundwater. Plants and
  animals can store small amounts of TCB.

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HOW DOES TCB AFFECT HUMAN HEALTH AND THE ENVIRONMENT?

       Effects of 1,2,4-trichlorobenzene on human health and the environmental depend on how much TCB is present
and the length and frequency of exposure. Effects also depend on the health of a person or the condition of the
environment when exposure occurs.

       1,2,4-Trichlorobenzene vapor irritates the eye and respiratory tract. Direct contact with TCB irritates the skin
and may cause dermatitis. Liver damage and nervous system effects such as tremors have occurred in experimental
animals exposed to high levels of TCB for short periods  of time.  These acute effects are not likely to occur at levels of
TCB that are normally found in the U.S. environment.

       Human health effects associated with exposure  of small amounts of 1,2,4-trichlorobenzene over long periods
of time are not known.  Several repeat-dose laboratory animal studies have shown that TCB can adversely  affect the
liver, the kidney, and the adrenal gland. An animal study has shown that repeat exposure of mothers to large amounts
of TCB in drinking water causes adverse effects of the adrenal gland in pups. The chlorinated benzene industry has
completed cancer studies on TCB in animals in response to an EPA request for testing. Large amounts of  1,2,4-
trichlorobenzene in the diet of these animals causes cancer in mice but not in rats. The information has limited use in
assessing the potential of TCB to cause cancer in humans.

       The chlorinated benzene industry has also completed aquatic toxicity studies on 1,2,4-trichlorobenzene in
response to an EPA request for testing.  Results show that TCB is highly toxic to aquatic life.


WHAT EPA  OFFICES OR OTHER FEDERAL AGENCIES CAN I CONTACT FOR ADDITIONAL
INFORMATION ON THE REGULATION OF TCB?

       EPA OFFICES                       STATUTE                    PHONE NUMBER
       Pollution  Prevention                  Pollution Prevention Act (PPA)  (202)260-1023
         and Toxics                        Emergency Planning and
                                             Community Right-to-Know Act
                                             (EPCRA) ( 313/TRI)         (800)535-0202
                                           Toxic Substances Control Act
                                             (TSCA) (4, 8A, 8D)          (202)554-1404
       Pesticides                           Federal Insecticide, Fungicide
                                             and Rodenticide Act (FIFRA)  (800)858-7378
       Air                                  Clean Air Act                 (919)541-0888
       Solid Waste and                      Resource Conservation and
       Emergency Response                   Recovery Act (RCRA)         (800)535-0202
                                           Comprehensive Environmental
                                             Response, Compensation, and
                                             Liability Act (CERCLA)        (800)535-0202
       Water                              Clean Water Act               (202)260-7588
                                           Safe Drinking Water Act        (800)426-4791
                                           (Drinking Water Standard: 0.07 mg/L)

       OTHER FEDERAL AGENCIES/DEPARTMENTS                     PHONE NUMBER

       Agency for Toxic Substances & Disease Registry                     (404) 639-6000
       American Conference of Governmental Industrial Hygienists             (513) 742-2020
       Consumer Product Safety Commission                               (301) 504-0994
       Food and Drug Administration                                       (301) 443-3170
       National Institute for Occupational Safety and Health                   (800) 356-4674
       Occupational Safety & Health Administration
         (Check local phone book for phone number under Department of Labor)

The Support Document for this  and other OPPT Chemical Fact Sheets can be found on the Internet at:
       http://www.epa.gov/chemfact

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