phenmedipham (Betanal, Spin-Aid) Herbicide Profile 2/85
CHEMICAL NAME: Methyl-m-hydroxycarbanilate-m-methylcarbanilate
TRADE NAME(S): Spin-aid, Betanal (56)
FORMULATION(S): Emulsifiable concentrate (1.3 pounds/gallon) (56)
TYPE: Postemergence herbicide
BASIC PRODUCER(S): NOR-AM Agricultural Products, Inc.
350 W. Shuman Blvd.
Naperville, IL 60566
STATUS: General use
PRINCIPAL USES: For control of weeds such as kochia, lambsquarters,
mustard, green foxtail, etc. in red table beets and spinach (56).
Postemergence sugarbeet herbicide for control of annual weeds such as
lambsquarters, shepherdspurse, dogfennel, yellow mustard, chickweed,
wild radish, ragweed, kochia, wild buckwheat, foxtail, nightshade,
field pennycress, London rocket, purslane, fiddleneck, ground cherry,
and goosefoot (58).
APPLICATION METHOD(S): Phenmedipham is applied as a postemergence
spray. It is applied either broadcast or as a band treatment. Apply
when beets are at the 2 true-leaf stage or larger. Weeds should be
at the cotyledonary to 2-leaf stage for best results (58).
Group I: Weeds susceptible to Betanal if sprayed before reaching the
Common Name Scientific Name
lambsquarters Chenopodium album
wild buckwheat Polygonum convolvulus
green foxtail Setaria viridis
pigeon grass (yellow foxtail) Setaria glauca
mustard Brassica spp.
purslane Portulaca oleracea
chickweed Stellaria media
shepherdspurse Capsella bursa-pastoris
London rocket Sisymbrium irio
Group II: Weeds which may be controlled if sprayed before reaching the
prostrate pigweed Amaranthus graecizans
nightshade Solanum spp.
ragweed Ambrosia spp.
kochia* Kochia scoparia
fiddleneck Amsinckia spp.
ground cherry Pysalis spp.
goosefoot Chenopodium murale
* Spray kochia while in the rosette stage, less than 1 inch in diameter
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C16 H16 N2 O4 (62)
MOLECULAR WEIGHT: 300.3 (62)
PHYSICAL STATE: Colorless crystals (pure compound) (62); amber
colored liquid (Betanal) (36d).
ODOR: Faint solvent odor (Betanal) (36d)
MELTING POINT: 143-144 C (pure compound); 140-144 C (technical
product, >95% pure) (62).
VAPOR PRESSURE: 1.3 nPa at 25 C (technical product) (62)
SOLUBILITY: 4.7 mg/l water at room temperature (pure compound)
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: NA
NIOSH RECOMMENDED LIMIT: NA
ACGIH RECOMMENDED LIMIT: NA
A. ACUTE TOXICITY
DERMAL: LD50 = >4000 mg/kg (rat) (phenmedipham) (58)
LD50 (for Betanal - 15.9% phenmedipham): >20,000
mg/kg (rat); >10,000 mg/kg (rabbit) (58).
LD50 (for formulation less active ingredient):
13,500 mg/kg (rat); 3900 mg/kg (rabbit) (58).
ORAL: LD50 = >8000 mg/kg (rats and mice); >4000 mg/kg
(dogs and guinea pigs); >3000 mg/kg (chickens)
LD50 = 2000 mg/kg (rat, Betanal-15.9 phenmedipham)
INHALATION: LC50 (4 hour exposure), aerosol inhalation,
undiluted Betanal: more than 6.2 mg/l (rat)
B. SUBACUTE AND CHRONIC TOXICITY:
In 120-d feeding trials rats receiving up to 500 mg a.i./kg
daily survived, but there was a reduced food intake dependent on the
A 2-year rat oncogenicity study showed no compound related
histomorphologic alterations at dietary levels of 500 ppm and less.
A 2-year dog feeding study showed no compound related effects at dietary
levels of 1000 ppm and less (58).
C. EPA TOLERANCE SUPPORT DATA:
The toxicological data considered in support of the proposed
tolerance included: A three-generation rat reproduction study with a
no-observable-effect-level (NOEL) (for reproductive effects) of 500 ppm
(highest dose tested); a rat teratology study with no teratogenic or
fetal toxic effects noted at 500 ppm (highest dose tested); a two-year
dog feeding study with a NOEL of 1,000 ppm (highest dose tested); a rat
chronic feeding and oncogenic study with no unusual incidence of tumor
formation and a NOEL (based on body weight change) of 100 ppm; and a
mouse mutagenic potential study (using micronucleus test) with no
evidence of mutagenicity (53b).
IV. ENVIRONMENTAL CONSIDERATIONS
In soil, 71-86% of the amount determined 1 d after treatment was
degraded in 90 d, mainly to methyl 3-hydroxycarbanilate (62).
Phenmedipham remains in the top layers of soil (0 to 2 inches)
after application. Half-life of phenmedipham is approximately 25 days
Rainbow trout: some toxic symptoms at 0.01 ml of phenmedipham per
liter of water; lethal concentration 0.02 ml of phenmedipham per
No effect on trout at 1.6 mg a.i. (as 'Betanal')/l and carp
2.4 mg a.i. (as 'Betanal')/l (62).
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
SYMPTOMS OF POISONING: Massive doses might cause signs of central
nervous system stimulation such as hyperactivity, tremors or muscle
SKIN CONTACT: Thoroughly rinse contaminated areas (58).
INGESTION: Induce vomiting (58).
EYE CONTACT: Thoroughly rinse contaminated areas (58).
VI. FIRE AND EXPLOSION INFORMATION
GENERAL: Flash point: 74 C - TCC (58). When Betanal is subjected to
extremely high temperatures such as in a warehouse fire, it may
decompose and give off poisonous vapors. Personnel fighting the fire
should wear a self-contained breathing apparatus (36d).
EXTINGUISHER TYPE: Any type extinguisher may be used; however, water
should not be used if there is a chance that run-off may contaminate
water supplies (36d).
Phenmedipham presents no particular corrosion problems (58).
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Do not store below 20 C. Avoid breathing spray
mist (56). Phenmedipham has a shelf life of over 1 year. Do not
breathe spray mist. Do not eat, drink, or smoke while spraying (58).
PROTECTIVE CLOTHING: None required (56).
PROTECTIVE EQUIPMENT: Wear goggles to prevent splashing into eyes (56).
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
Betanal spillage should be absorbed in a suitable material such as
sawdust or lime. The area should then be washed with water containing
ammonia and a detergent. Wear rubber gloves (synthetic or natural)
when cleaning up Betanal spillage. Make sure that spillage or wash
water does not contaminate sewers or waterways. Material used for
soaking up Betanal spillage and washing liquids used for cleaning up
contaminated areas should be placed in a separate container and treated
with lime and soda ash for several hours prior to disposal in a
designated area away from water supplies. Check local and state
authorities for regulations with regard to pesticide disposal (36d).
X. LITERATURE CITED
36c. Nor-Am Agricultural Products, Inc. 1973. Information bulletin:
Betanal. Chicago, IL.
36d. Nor-Am Agricultural Products, Inc. ---- . Safety manual: Betanal
post-emergence sugar beet herbicide. Chicago, IL.
53b. U.S. Government Printing Office. 1981. Federal Register.
46(236):60217-60218. Superintendent of Documents.
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.