Desmedipham (Betanex) Herbicide Profile 3/85
CHEMICAL name: Ethyl m-hydroxycarbanilate carbanilate (ester)
TRADE name(S): Betanex (58)
FORMULATION(S): Emulsifiable concentrate (1.3 lb/gal) (56)
TYPE: Carbamate herbicide
BASIC PRODUCER(S): NOR-AM Agricultural Products, Inc.
350 W. Shuman Blvd.
Naperville, IL 60566
STATUS: General use
PRINCIPAL USES: Postemergence sugarbeet herbicide for control of
annual weeds such as pigweed, mustard, lambsquarters, nightshade,
shepherdspurse, London rocket, chickweed, buckwheat, ragweed,
fiddleneck, and kochia (58).
APPLICATION METHOD(S): Desmedipham is applied as a postemergence
foliar spray, etiher as a broadcast or as a band application (58).
Important Weeds Controlled: The same as Betanal (phenmedipham) except
most effective on pigweed (8b).
Rainfall within 6 hours will reduce the effectiveness (8b).
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C16 H16 N2 O4 (58)
MOLECULAR WEIGHT: 300.3 (58)
PHYSICAL STATE: Colorless or light yellow crystalline substance
(pure compound) (58); the technical grade is c. 96%
MELTING POINT: 120 C (pure compound) (58)
VAPOR PRESSURE: Low (pure compound) (58); 400 nPa at 25 C (pure
SOLUBILITY: 9 mg/l water at room temperature (pure compound)
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: None established
NIOSH RECOMMENDED LIMIT: None established
ACGIH RECOMMENDED LIMIT: None established
A. ACUTE TOXICITY
DERMAL: LD50 = >318 mg a.i. (as e.c.)/kg (rabbit) (62).
LD50 = >2,025 <10,250 mg/kg (rabbit, Betanex-16%
Some irritation may occur after prolonged skin
contact with Betanex (16.0% desmedipham) (58).
ORAL: LD50 = 10,260 mg a.i./kg (rat) (62).
LD50 = 3,720 mg/kg (rat), 2,150 mg/kg (dog-minimum
lethal dose) (Betanex-16% desmedipham) (58).
B. SUBACUTE AND CHRONIC TOXICITY:
Ninety-day feeding studies with Betanex (containing 16.0%
desmedipham) on rats and dogs showed a no-effect level of more than
1,250 ppm of the formulation in the diet (58).
IV. ENVIRONMENTAL CONSIDERATIONS
Behavior In Or On Soils
1. Adsorption and leaching characteristics in basic soil types:
Desmedipham remains in the top layers of soil (0 to 2 inches)
after application. No appreciable leaching occurs.
2. Resultant average persistence at recommended rates: Half life of
desmedipham in silty loam, sandy loam and silty clay loam
soils was less than 1 month (58).
General toxicity to wildlife and fish:
Toxicities of Betanex (16% desmedipham):
Bobwhite quail, oral LC50 - 4 days - 2,480 mg/kg
Trout LC50 - 96 hr 3.8 ppm
Bluegill LC50 - 96 hr 13.4 ppm (58)
Acute oral LD50 = 390 mg a.i. (as e.c./kg) (quail) (62).
LC50 (96 hr) is: for rainbow trout 0.6 mg a.i. (as e.c.)/l;
for bluegill 2.1 mg a.i. (as e.c.)/l (62).
Toxic to fish (8b).
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 substitute for a more exhaustive
review of the literature nor for the judgement of a physician or other
If poisoning is suspected, do not wait for symptoms to develop.
Contact a physician, the nearest hospital, or the nearest Poison
SYMPTOMS OF POISONING: Hypoactivity, muscular weakness (58).
SKIN CONTACT: Thoroughly rinse contaminated areas (58).
INGESTION: Induce vomiting (58).
EYE CONTACT: Thoroughly rinse contaminated areas (58).
VI. FIRE AND EXPLOSION INFORMATION
Flammability: Flash point: 68 C (TOC-ASTM D-1310) (58).
Desmedipham formulation presents no particular corrosion problems
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Betanex was stable for 4.5 months during an
accelerated storage test at 70 C. Do not breathe spray mist. Do not
eat, drink, or smoke while spraying (58).
Do not store below -20 C. Wear goggles to prevent splashing into
PROTECTIVE CLOTHING: None required (56).
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
X. LITERATURE CITED
8b. Thomson, W.T. 1981. Agricultural chemicals - book 2:
herbicides. Revised ed. Thomson Publications, Fresno, CA.
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.