United States Office of Water EPA 811-F-95-003 n-T
Environmental Protection 4601 October 1995
Agency
National Primary Drinking
Water Regulations
Endothall
CHEMICAL/PHYSICAL PROPERTIES DENSITY/SPEC. GRAV.: 1.431at15°C BIOCONCENTRATION FACTOR:
: BCF <1 in fish; not expected to biocon-
CAS NUMBER: 145-73-3 SOLUBILITY: 100 g/L of water at 20° C; centrate in aquatic organisms.
Very soluble in water
COLOR/ FORM/ODOR: TRADE NAMES/SYNONYMS:
Odorless, white crystals SOIL SORPTION COEFFICIENT: Hexahydro-3,6-endo-epoxy-1,2-
.. n <**.^^ * Koc <2; high mobility in soil benzenedicarboxylic acid; Accelerate;
M.P, 144 C (decomposes) QDO^ASTE THRESHOLDS: N/A Aquathol; Des-i-cate; Endothal. Turf
VAPOR PRESSURE: very low at room temp. . ' Herbicide; Endothall Weed Killer;
HENRY'S LAW COEFFICIENT: N/A Herbicide 273; Hydrothol; Herbon
OCTANOL/WATER PARTITION (Kow): N/A Pennout; Hydout.
DRINKING WATER STANDARDS clover desiccants; potato vine killers.
MCLG: 0.1 mg/L EPA estimated total domestic usage in 1982 to have
MCL- 0 1 mg/L been aPProximate'y 1 -5 million Ibs. In California in 1984,
87,000 Ibs. of the mono(N,N-diethylalkylamine) salt were
HAL(child): 1- to 10-day: 0.8 mg/L used; 4 000 ,bs of the dimethylamine salt were used;
Longer-term: 0.2 mg/L minor amounts of the dimethylalkylamine and dipotassium
salts were used. Its estimated applications in California
HEALTH EFFECTS SUMMARY were as follows: Cotton production, 95.6%; Sugarbeets,
Acute: EPA has found endothall to potentially cause 3-9%: Remainder in landscape maintenance or "public
the following health effects from acute exposures at health Pest control-
levels above the MCL: depressed breathing and heart _ _
. RELEASE PATTERNS
Drinking water levels which are considered "safe" for Release of endothall to the environment is expected to
short-term exposures: For a 10-kg (22 Ib.) child consum- occur Pnmanly dunng its use as a pre-emergence, post-
ing 1 literofwaterperday, upto a ten-day exposure to 0.8, emergence, turf and aquatic herbicide and harvest a.d.
or up to a 7-year exposure to 0 2 mg/L Other sources of release include loss dunng manufactur-
ing, formulation, packaging or disposal of this herbicide.
Chronic: Endothall has the potential to cause the _. . „_ „. . ,- . . . . ,. tu -r •
following health effects from long-term exposures at S,nce endothall ,s not a listed chem.cal m the Tox.cs
levels above the MCL: increased organ weights and Release Inventory, data on releases dunng .ts manufac-
organ-to-body weight ratios of stomach and intestine. ture and handlin9 are not available'
Cancer: There is inadequate evidence to state whether ENVIRONMENTAL FATE
or not endothall has the potential to cause cancer from a re|eased SQ endotha)| js e d {Q jd|
lifetime exposure in drinking water. biodegrade under aerobic conditions. The half-life of
endothall in soil is reported to be 4 to 9 days. Endothall
USAGE PATTERNS should be highly mobile in soil; however, rapid degrada-
Endothall is used as a defoliant for a wide range oftion would limit the extent of leaching. Its persistence in
Irops and as a herbicide for both terrestrial and aquatic soil may De prolonged by adsorption to organic matter or
weeds. It is used as a desiccant on lucerne and on potato, by factors inhibiting microbial activity. Chemical hydroly-
forthe defoliation of cotton, to control aquatic weeds and sis and volatilization are not expected to be significant.
as an aquatic algicide growth regulator. It has been used |f released to water, endothall should rapidly biode-
for: sugar beets, turf, hops sucker suppression; alfalfa, grade under aerobic conditions (half-life approximately 1
October 1995 Technical Version Printed on Recycled Paper
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week or less) and biodegrade more slowly under anaero-
bic conditions. Glutamic acid is a major biotransformation
product of endothall under aerobic conditions. Endothall
is not expected to oxidize, chemically hydrolyze, photo-
lyze, volatilize or adsorb to suspended solids or sedi-
ments in water. The soil adsorption coefficient (Koc) of
endothall in sediment/water systems has been mea-
sured to be < 2.
If released to the atmosphere, endothall is expected to
exist predominantly on particles and should either settle
out or wash out in precipitation. It is not expected to
chemically react or photolyze in the atmosphere.
The whole body bioconcentration factor (BCF) of en-
dothall in bluegill (Lepomis macrochirus) has been mea-
sured to be < 1. Based on a its water solubility, a BCF of
< 1 has also been calculated. With these BCF values,
endothall is not expected to bioaccumulate in aquatic
organisms.
The most probable routes of human exposure to endo-
thall are inhalation and dermal contact of workers in-
volved in the manufacture, handling or application of
endothall. The general public could potentially be ex-
posed through use for lawn weed control.
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 >33QO persons;
1 sample per 3 years for smaller systems
TRIGGERS - Return to Initial Freq. rf detect at > 0.009 mg/L
ANALYSIS: '•
REFERENCE SOURCE METHOD NUMBERS
EPA 600/4-88-039 548.1
TREATMENT:
BEST AVAILABLE TECHNOLOGIES
Granular Activated Charcoal
FOR ADDITIONAL INFORMATION:
* EPA can provide further regulatory and other general information:
• EPA Safe Drinking Water Hotline - 800/426-4791
A 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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