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.: -9°C 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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