dalapon (Dowpon, Revenge) Herbicide Profile 2/85
CHEMICAL NAME: 2,2-Dichloropropionic acid (56)
TRADE NAME(S): Dalapon 85, Dowpon, Dowpon M, Radapon Liquid,
FORMULATION(S): Dowpon - the sodium salt of dalapon; Dowpon M -
contains 72.5% of sodium salt and 12.0% magnesium salt of dalapon;
Radapon Liquid - a liquid formulation of sodium salt of dalapon;
Revenge - contains 46.7% sodium salt of dalapon, 7.8% of magnesium salt
of dalapon, and 30.6% sodium TCA (58).
TYPE: Aliphatic acid herbicide
BASIC PRODUCER(S): SDS Biotech Corp.
7528 Auburn Rd.
P.O. Box 348
Painesville, OH 44077
Vertac Chemical Corp.
Memphis, TN 38137
STATUS: General use
PRINCIPAL USES: For the control of annual and perennial grasses,
dalapon is used in sugarcane, sugarbeets, corn, potatoes, asparagus,
grapes, flax, new legume spring seedlings, citrus, and deciduous fruit;
coffee, certain stone fruits, nut trees, and on noncrop lands (58).
APPLICATION METHOD(S): Can be applied with conventional aerial or
ground equipment as a foliage application. Apply prior to crop
emergence or postemergence. Addition of wetting agent is usuallly
Effective against quackgrass, bermudagrass, johnsongrass, and
other perennial and annual grasses as well as cattails and rushes.
Often it is used as a preplant treatment to control established
perennial grasses in cropland and noncropland areas and irrigation
ditch banks in 17 western states. It is translocated to the roots of
most species and acts as a growth regulator (58).
Important Weeds Controlled: Quackgrass, bluegrass, Johnsongrass,
barnyardgrass, Bermudagrass, foxtails, crabgrass, cattails, paragrass
and most other perennial and annual grasses (8b).
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C3 H4 Cl2 O2 (dalapon); C3 H3 Cl2 Na O2
MOLECULAR WEIGHT: 143.0 (dalapon); 165.0 (dalapon-sodium) (62).
PHYSICAL STATE: Colorless liquid (dalapon); hygroscopic powder
Colorless liquid (pure compound); off-white
powder (Dowpon M - contains 72.5% of sodium salt
and 12% magnesium salt of dalapon) (58).
ODOR: Odorless (pure compound) (58)
MELTING POINT: 166.5 C (dalapon-sodium, decomposes before melting)
Decomposes before melting (Dowpon M) (58)
DECOMPOSITION TEMPERATURE: 167.7 C (Dowpon M) (58)
BOILING POINT: 185-190 C (pure compound) (58)
SOLUBILITY: Very soluble in water (pure compound); 110 g/100 ml
of water having 100 ppm hardness (Dowpon M) (58).
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: NA
NIOSH RECOMMENDED LIMIT: NA
ACGIH RECOMMENDED LIMIT: TWA (Time Weighted Average) = 1 ppm; 6 mg/m3
A. ACUTE TOXICITY
DERMAL: Moderate irritation, even a mild burn, upon repeated
prolonged contact. Occasional contact not likely to
cause significant irritation. Not absorbed through
the skin in toxic amounts (58).
It is corrosive to the skin (15b).
ORAL: LD50 = 970 mg/kg (tech a.i.), 7570 mg/kg (sodium salt)
(female rat) (56).
LD50 (mg/kg) - 9330 (male rat); 7570 (female rat);
>4600 (female mouse); 3860 (female guinea-pig); 3860
(female rabbit); 5660 (chick, mixed) (58).
INHALATION: Dusts may be irritating to upper respiratory
tract. Not likely to cause systemic injury (58).
Rats exposed for 7 hours to an atmosphere saturated
with dalapon vapor showed no ill effects (15b).
EYES: Moderate irritation and transient corneal injury.
Healing should be complete in several days (58).
It can cause permanent eye injury (15b).
B. SUBACUTE AND CHRONIC TOXICITY:
In 2-year feeding trials no effect was observed in rats receiving
15 mg/kg daily, there was a slight increase in kidney weight in rats at
50 mg/kg daily (62).
A 120-day diet study of rats indicated a no-ill-effect level of 15
Dogs - 1 year, 100 mg/kg per day - slight average kidney weight
increase. 50 mg/kg per day - no adverse effects (58).
Heifer calf - 10 days. 1000 mg/kg per day - general nonspecific
symptoms during last of experiment but completely recovered upon
cessation of dosing.
Bull calf - 10 days. 1000 mg/kg per day - no adverse effects
during dosing. Autopsy showed possible slight kidney involvement.
Dogs - 80 days. Daily doses 5 days a week: Doses started at 50
mg/kg per day but gradually increased to 1000 mg/kg per day. Other
than vomiting, dogs were not adversely affected (58).
Occupational vapor exposures up to 2.65 ppm (TWA) have been observed;
minimal respiratory irritation was noted at concentrations between 2
and 7 ppm (15b).
IV. ENVIRONMENTAL CONSIDERATIONS
Goldfish mortality at the end of 24 hr of exposure was 0% at 100
ppm and 100% at 500 ppm and above. In static water on twelve species
of fish including rainbow trout and coho salmon, the LC50 was greater
than 100 ppm of dalapon which represents a very low order of toxicity
to fish. In short exposure tests, the no effect level of dalapon for
snails, dragonflies, stoneflies, and several crustaceans is at least
200 ppm (58).
Behavior In Or On Soils
1. Adsorption and leaching characteristics in basic soil types:
Leaches readily in soils.
2. Microbial breakdown: Breaks down rapidly and completely in soil.
Several organisms have been isolated and identified (58).
LC50 (5-day) for pheasants, Japanese quail, and mallard duck was
>500 mg dalapon-sodium/kg diet. LC50 (96-hr) for rainbow trout,
channel catfish and goldfish >100 mg/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
KNOWN OR SUSPECTED ADVERSE EFFECTS: Skin and eye irritant (25).
Symptoms are likely to be general in nature and may include a
feeling of lassitude, vomiting, diarrhea, slowing of pulse, loss of
SKIN CONTACT: Wash contaminated skin with soap and water (25).
INGESTION: Ingestions of small amounts (less than 10 mg/kg body
weight) occurring less than an hour before treatment, are probably best
A. Syrup of Ipecac, followed by 1-2 glasses of water. Dose for
adults and children over 12 years: 30 ml. Dose for children
under 12 years: 15 ml.
B. Activated Charcoal - Administer 30-50 gm as a slurry in tap water,
after vomiting stops.
C. Sodium of Magnesium Sulfate, 0.25 gm/kg in tap water, as a
EYE CONTACT: Flush contaminated eyes with copious amounts of
fresh water for 15 minutes (25).
NOTES TO PHYSICIAN:
1. INGESTIONS of LARGE amounts (more than 10 mg/kg) occurring less
than an hour before treatment, should probably be treated by
A. INTUBATE stomach and ASPIRATE contents.
B. LAVAGE stomach with slurry of ACTIVATED CHARCOAL in 0.9%
saline. Leave 30-50 gm activated charcoal in the stomach
before withdrawing tube.
C. SODIUM SULFATE, 0.25 gm/kg in tap water, as a cathartic.
CAUTION: Hydrocarbons (kerosene, petroleum distillates) are
included in some formulations of these chemicals.
Ingestion of very LARGE AMOUNTS may cause CNS
depression. In this case, IPECAC IS
CONTRAINDICATED. Also, gastric intubation incurs a
risk of HYDROCARBON PNEUMONITIS. For this reason
observe the following precautions:
(1) If the victim is unconscious or obtunded and
facilities are at hand, insert an ENDOTRACHEAL
TUBE (cuffed, if available) prior to gastric
(2) Keep victim's HEAD BELOW LEVEL OF STOMACH
during intubation and lavage (Trendelenburg, or
left lateral decubitus, with head of table
tipped downward). Keep victim's head turned to
(3) ASPIRATE PHARYNX as regularly as possible to
remove gagged or vomited stomach contents.
2. INGESTIONS occurring MORE THAN an HOUR before treatment are
probably best treated only by ACTIVATED CHARCOAL, 30-50 gm, and
SODIUM or MAGNESIUM SULFATE, 0.25 gm/kg, as described above.
3. There are no specific antidotes for these chemicals. Because
manifestations of toxicity do occasionally occur in peculiarly
predisposed individuals, MAINTAIN CONTACT with victim for at least
72 hours so that unexpected adverse effects can be treated
VI. FIRE AND EXPLOSION INFORMATION
Compatible with hard water and liquid fertilizers. Formulations
are mildly corrosive to equipment (58).
It is subject to hydrolysis, slight at 25 C but comparatively
rapid at greater than or equal to 50 C; so aqueous solutions should
not be kept for any length of time. Alkali causes dehydrochlorination
above 120 C. Its solutions are corrosive to iron (62).
May be combined with other specified herbicides such as atrazine
and others (8b).
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Do not contaminate water, food, or feed by
storage or disposal of this product. Do not use spray equipment
contaminated with this product for any purpose unless thoroughly
cleaned with a suitable cleaner (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.
15b. American Conference of Governmental Industrial Hygienists. 1971.
Documentation of the threshold limit values for substances in
workroom air with supplements for those substances added or
changed since 1971, 3rd ed., 4th printing (1977). Cincinnati,
OH. 484 pp.
15c. American Conference of Governmental Industrial Hygienists. 1984.
TLVs: threshold limit values for chemical substances and
physical agents in the work environment and biological exposure
indices with intended changes for 1984-85. Cincinnati, OH.
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.