Endothall - Herbicide Profile 2/85
CHEMICAL NAME: 7-Oxabicyclo (2,2,1)heptane-2,3-dicarboxylic acid
(used as sodium, potassium, or amine salts) (56)
TRADE NAME(S): Endothal Technical (acid) (58)
FORMULATION(S): Water-miscible, granular, and pelletized in various
These include: disodium, diammonium and mono(ethyl-
dimethylammonium) salts (62).
TYPE: Herbicide - growth regulator
BASIC PRODUCER(S): Pennwalt Corp.
Ag Chem Div.
Philadelphia, PA 19102
STATUS: General use
PRINCIPAL USES: Herbicide, pre- and postemergence; defoliant;
desiccant; aquatic algicide and herbicide; growth regulator. Many
derivatives or formulations of endothall are being used on sugar beets
and turf; as aquatic herbicides and algicides; as alfalfa and clover
dessicants; and as cotton harvest aids, and as potato vine killers
To be developed.
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C8 H10 O5 (62)
MOLECULAR WEIGHT: 186.2 (62)
PHYSICAL STATE: Colorless solid (hydrate) (62)
ODOR: Odorless (pure compound) (58)
MELTING POINT: 144 C (hydrate) (62)
DECOMPOSITION TEMPERATURE: Stable to about 90 C, at which
temperature it undergoes a slow conversion to anhydride (58).
SOLUBILITY: 100 g/kg water at 20 C (hydrate) (62)
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: NA
NIOSH RECOMMENDED LIMIT: NA
ACGIH RECOMMENDED LIMIT: NA
A. ACUTE TOXICITY
DERMAL: Endothal-sodium (19.2% formulation) causes light to
moderate skin irritation (62).
May be absorbed through the skin, causing light to
moderate irritation. More severe effects at
concentrations over 1%, with an immediate burning
sensation on abraded skin (58).
ORAL: LD50 (rat) = 51 mg endothal/kg; 182-197 mg
endothal-sodium (for 19.2% formulation)/kg (62).
LD50 (rat) = 38-51 mg/kg for acid (technical);
182-197 mg/kg for Na salt (19.2% solution);
206 mg/kg for amine salt (66.7% formulation) (58).
EYES: Greatest occupational hazard is eye irritation
caused by burning of tissues on exposure (58).
B. SUBACUTE AND CHRONIC TOXICITY:
In 2-year feeding trials rats receiving 1000 mg/kg diet suffered
no ill-effect (62).
Two-year dog and rat oral feeding studies were performed with
disodium endothall and it was demonstrated that for rats (which are the
most sensitive) a "no harmful effect" dosage level is in excess of 300
ppm. Since the residues of disodium endothall likely to remain on
agricultural commodities under conditions of use would not exceed 10
ppm, the safety factor is at least 150 (calculated on possible daily
intake by humans) and, therefore, would not constitute a hazard to
public health (58).
IV. ENVIRONMENTAL CONSIDERATIONS
Disappears from soil and water by microbiological breakdown at
rates dependent upon soil temperature, moisture, type, and
microbiological activity (58).
V. EMERGENCY AND FIRST AID PROCEDURES
The chemical information provided below has been condensed
from original source documents, primarily from "Recognition and
Management of Pesticide Poisonings", 3rd ed. by Donald P. Morgan,
which have been footnoted. This information has been provided in
this form for your convenience and general guidance only. In
specific cases, further consultation and reference may be required
and is recommended. This information is not intended as a sub-
stitute for a more exhaustive review of the literature nor for the
judgement of a physician or other trained professional.
If poisoning is suspected, do not wait for symptoms to develop.
Contact a physician, the nearest hospital, or the nearest Poison
FREQUENT SYMPTOMS AND SIGNS OF POISONING
It is irritating to eyes, mucous membranes and skin, but it is not
sensitizing. Mechanisms of systemic toxicity are not clear, but the
central nervous system, heart, blood vessels, and gastrointestinal
lining appear to be primary targets. Poisoned animals exhibit ataxia,
convulsions, shock, and respiratory depression. Erosions and ulcers of
the gastrointestinal tract follow ingestion.
There are no standard analytical methods for confirming poisoning
SKIN CONTACT: Wash contaminated skin (25).
INGESTION: Instead of gastric evacuation following ingestion,
administer cold milk or aluminum hydroxide gel (25).
EYE CONTACT: Flush eyes with copious amounts of water (25).
NOTES TO PHYSICIAN:
Wash contaminated skin and flush eyes with copious amounts of
water. Instead of gastric evacuation following ingestion, administer
cold milk or aluminum hydroxide gel. This may be followed by saline
catharsis. There is no specific antidote. Shock may require blood
transfusions. Use of adrenergic amines is probably hazardous in view
of myocardial irritability (25).
VI. FIRE AND EXPLOSION INFORMATION
To be developed.
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Stable to light. Liquid formulations should be
stored at 0 C or above to prevent crystallization (58).
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
X. LITERATURE CITED
25. Morgan, D.P. 1982. Recognition and management of pesticide
poisonings, 3rd ed. U.S. Environmental Protection Agency,
Washington, DC. 120 pp.
56. Farm Chemicals Handbook, 70th ed. 1984. R. T. Meister, G. L.
Berg, C. Sine, S. Meister, and J. Poplyk, eds. Meister
Publishing Co., Willoughby, OH.
58. Weed Science Society of America, Herbicide Handbook Committee.
1983. Herbicide handbook of the weed science society of
America, 5th ed. Weed Science Society of America, Champaign,
IL. 515 pp.
62. The Pesticide Manual: A World Compendium, 7th ed. 1983. C.R.
Worthing, ed. The British Crop Protection Council, Croydon,
England. 695 pp.