United States
                             Environmental Protection
                             Agency
                     Office of Water
                     4601
            EPA 811-F-95-003I-T
                  October 1995
                             National Primary Drinking
                            Water Regulations
                             Hexachlorocyclopentadiene
  CHEMICAL/ PHYSICAL PROPERTIES

  CAS NUMBER:.77-47-4

  COLOR/ FORM/ODOR:
    dense, oily, yellow green liquid with a
  -  pungent odor.

  M.P.: -9C    B.P.: 239 C

  VAPOR PRESSURE: 0.08 mm Hg at 25 C
OCTANOL/WATER PARTITION (Kow):
  Log Kow = 3.99

DENSITY/SPEC. GRAV.: 1.7 at 25 C

SOLUBILITY: 2 m/L of water at 25 C;
  Insoluble in water

SOIL SORPTION COEFFICIENT:
  Koc measured at 4,265; low mobility
  in soil
ODOR/TASTE THRESHOLDS:  N/A

EtlOCONCENTRATlON FACTOR:
  BCFs range from 100 to 1230 in fish;
  some potential to bioconcentrate in .
  aquatic organisms.

HENRY'S LAW COEFFICIENT:
  2.7x1 Or2 atm-cu m/mole;

TRADE NAMES/SYNONYMS:
  HEX, Hexachloropentadiene
DRINKING WATER STANDARDS
  MCLG:      0.05 mg/L
  MCL:       0.05 mg/L
  HAL(child):  none

HEALTH EFFECTS SUMMARY
  Acute: EPA has found hexachlorocyclopentadiene
(HEX) to potentially cause the following health effects
from acute exposures at levels above the MCL: gastroi-
ntestinal distress; damage to liver, kidneys and heart.
  At present, EPA has issued no drinking water health
advisory providing guidance on safe levels for short-term
exposures to this chemical in drinking water.
  Chronic: HEX has the potential to cause the following
health effects from long-term exposures at levels above
the MCL: damage to the stomach and kidneys.
  Cancer:  There is no evidence that HEX has the
potential to cause cancer from a  lifetime  exposure in
drinking water.

USAGE PATTERNS
  It has been estimated that between 8 and 15 million Ibs.
of HEX are produced each year.
  Its greatest use is as  an intermediate  in chemical
.manufacture, including the synthesis of chlorinated pes-
Jcides, flame retardants, resins, dyes, Pharmaceuticals,
plastics, etc. HEX has no end uses of its own.
               RELEASE PATTERNS
                 Major sources of release of hexachlorocyclopentadiene
               to the environment are emissions and contaminated
               wastewater from facilities which manufacture or use this
               compound as a  chemical intermediate, and from the
               application of pesticides where it may remain as an
               impurity. Other sources are air emissions from the incin-
               eration of certain chlorinated wastes, and from water
               treatment plants receiving contaminated wastestreams.
                 From 1987 to 1993, according to EPA's Toxic Chemi-
               cal Release Inventory, HEX releases to land and water
               totalled only 78 Ibs., all of which was to water. These
               releases were primarily from alkalis and chlorine indus-
               tries. The largest releases occurred in New York.

               ENVIRONMENTAL FATE
                 Hexachlorocyclopentadiene is not a persistent envi-
               ronmental contaminant. If released to soil, it is predicted
               to be relatively immobile. In moist soil, this compound
               would be  subject to breakdown by light and chemical
               reaction (half-life hours to weeks). Volatilization from soil
               surfaces is expected to be minor.
                 If released to water, this compound will degrade within
               minutes to hours primarily by photolysis and chemical
               hydrolysis. Though HEX can adsorb to sediments, this
               does not slow its  rate of degradation. Volatilization from
               water is expected to be a significant removal mechanism,
               although high turbidity could extend the half-life to sev-
               eral weeks. Biodegradation is expected to be of minor
               importance.
                 Hexachlorocyclopentadiene could potentially bioac-
October 1995
         Technical Version
             Printed on Recycled Paper

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cumulate in some aquatic organisms depending upon
the   species.    Bioconcentration   factors   of
hexachlorocyclopentadiene in a laboratory model eco-
system: alga, 341; snail, 929; mosquito, 1634; and fish,
448.
                                                             OTHER REGULATORY INFORMATION	

                                                             MONITORING:
                                                             FOR GROUND/SURFACE WATER SOURCES:
                                                               INITIAL FREQUENCY-  4 quarterly samples every 3 years
                                                               REPEAT FREQUENCY- If no detections during initial round:
                                                                               2 quarterly per year if serving >3300 persons;
                                                                               1 sample per 3 years for smaller systems
                                                             TRIGGERS - Return to Initial Freq. rf detect at > 0.0002 mg/L
                                                                                          METHOD NUMBERS
                                                                                          505; 508; 508.1; 525.2
          ANALYSIS:
          REFERENCE SOURCE
          EPA 600/4-88-039

          TREATMENT:
          BEST AVAILABLE TECHNOLOGIES .
          Granular Activated Charcoal
                                                             FOR ADDITIONAL INFORMATION:
                                                             4  EPA can provide further regulatory and other general information:
                                                              EPA Safe Drinking Water Hotline -  800/426-4791

                                                             4  Other sources of lexicological and environmental fate data include:
                                                              Toxic Substance Control Act Information Line - 202/554-1404
                                                              Toxics Release Inventory, National Library of Medicine - 301/496-6531
                                                              Agency for Toxic Substances and Disease Registry - 404/639-6000
                                                              National Pesticide Hotline - 800/858-7378
October 1995
Technical Version
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